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/core/tv80_mcode_base.v
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// |
// TV80 8-Bit Microprocessor Core |
// Based on the VHDL T80 core by Daniel Wallner (jesus@opencores.org) |
// |
// Copyright (c) 2004 Guy Hutchison (ghutchis@opencores.org) |
// |
// Permission is hereby granted, free of charge, to any person obtaining a |
// copy of this software and associated documentation files (the "Software"), |
// to deal in the Software without restriction, including without limitation |
// the rights to use, copy, modify, merge, publish, distribute, sublicense, |
// and/or sell copies of the Software, and to permit persons to whom the |
// Software is furnished to do so, subject to the following conditions: |
// |
// The above copyright notice and this permission notice shall be included |
// in all copies or substantial portions of the Software. |
// |
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, |
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. |
// IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY |
// CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, |
// TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE |
// SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. |
|
module tv80_mcode_base |
(/*AUTOARG*/ |
// Outputs |
output_vector, |
// Inputs |
IR, MCycle, F, NMICycle, IntCycle, tstate |
); |
|
parameter Mode = 0; |
parameter Flag_C = 0; |
parameter Flag_N = 1; |
parameter Flag_P = 2; |
parameter Flag_X = 3; |
parameter Flag_H = 4; |
parameter Flag_Y = 5; |
parameter Flag_Z = 6; |
parameter Flag_S = 7; |
|
output [67:0] output_vector; |
|
input [7:0] IR; |
input [6:0] MCycle ; |
input [7:0] F ; |
input NMICycle ; |
input IntCycle ; |
input [6:0] tstate; |
|
// regs |
reg [2:0] MCycles ; |
reg [2:0] TStates ; |
reg [1:0] Prefix ; // None,BC,ED,DD/FD |
reg Inc_PC ; |
reg Inc_WZ ; |
reg [3:0] IncDec_16 ; // BC,DE,HL,SP 0 is inc |
reg Read_To_Reg ; |
reg Read_To_Acc ; |
reg [3:0] Set_BusA_To ; // B,C,D,E,H,L,DI/DB,A,SP(L),SP(M),0,F |
reg [3:0] Set_BusB_To ; // B,C,D,E,H,L,DI,A,SP(L),SP(M),1,F,PC(L),PC(M),0 |
reg [3:0] ALU_Op ; |
reg Save_ALU ; |
reg PreserveC ; |
reg Arith16 ; |
reg [2:0] Set_Addr_To ; // aNone,aXY,aIOA,aSP,aBC,aDE,aZI |
reg IORQ ; |
reg Jump ; |
reg JumpE ; |
reg JumpXY ; |
reg Call ; |
reg RstP ; |
reg LDZ ; |
reg LDW ; |
reg LDSPHL ; |
reg [2:0] Special_LD ; // A,I;A,R;I,A;R,A;None |
reg ExchangeDH ; |
reg ExchangeRp ; |
reg ExchangeAF ; |
reg ExchangeRS ; |
reg I_DJNZ ; |
reg I_CPL ; |
reg I_CCF ; |
reg I_SCF ; |
reg I_RETN ; |
reg I_BT ; |
reg I_BC ; |
reg I_BTR ; |
reg I_RLD ; |
reg I_RRD ; |
reg I_INRC ; |
reg SetDI ; |
reg SetEI ; |
reg [1:0] IMode ; |
reg Halt ; |
reg NoRead ; |
reg Write ; |
|
parameter aNone = 3'b111; |
parameter aBC = 3'b000; |
parameter aDE = 3'b001; |
parameter aXY = 3'b010; |
parameter aIOA = 3'b100; |
parameter aSP = 3'b101; |
parameter aZI = 3'b110; |
// constant aNone : std_logic_vector[2:0] = 3'b000; |
// constant aXY : std_logic_vector[2:0] = 3'b001; |
// constant aIOA : std_logic_vector[2:0] = 3'b010; |
// constant aSP : std_logic_vector[2:0] = 3'b011; |
// constant aBC : std_logic_vector[2:0] = 3'b100; |
// constant aDE : std_logic_vector[2:0] = 3'b101; |
// constant aZI : std_logic_vector[2:0] = 3'b110; |
|
function is_cc_true; |
input [7:0] F; |
input [2:0] cc; |
begin |
if (Mode == 3 ) |
begin |
case (cc) |
3'b000 : is_cc_true = F[7] == 1'b0; // NZ |
3'b001 : is_cc_true = F[7] == 1'b1; // Z |
3'b010 : is_cc_true = F[4] == 1'b0; // NC |
3'b011 : is_cc_true = F[4] == 1'b1; // C |
3'b100 : is_cc_true = 0; |
3'b101 : is_cc_true = 0; |
3'b110 : is_cc_true = 0; |
3'b111 : is_cc_true = 0; |
endcase |
end |
else |
begin |
case (cc) |
3'b000 : is_cc_true = F[6] == 1'b0; // NZ |
3'b001 : is_cc_true = F[6] == 1'b1; // Z |
3'b010 : is_cc_true = F[0] == 1'b0; // NC |
3'b011 : is_cc_true = F[0] == 1'b1; // C |
3'b100 : is_cc_true = F[2] == 1'b0; // PO |
3'b101 : is_cc_true = F[2] == 1'b1; // PE |
3'b110 : is_cc_true = F[7] == 1'b0; // P |
3'b111 : is_cc_true = F[7] == 1'b1; // M |
endcase |
end |
end |
endfunction // is_cc_true |
|
|
reg [2:0] DDD; |
reg [2:0] SSS; |
reg [1:0] DPAIR; |
|
always @ (/*AUTOSENSE*/F or IR or IntCycle or MCycle or NMICycle |
or tstate) |
begin |
DDD = IR[5:3]; |
SSS = IR[2:0]; |
DPAIR = IR[5:4]; |
|
MCycles = 3'b001; |
if (MCycle[0] ) |
begin |
TStates = 3'b100; |
end |
else |
begin |
TStates = 3'b011; |
end |
Prefix = 2'b00; |
Inc_PC = 1'b0; |
Inc_WZ = 1'b0; |
IncDec_16 = 4'b0000; |
Read_To_Acc = 1'b0; |
Read_To_Reg = 1'b0; |
Set_BusB_To = 4'b0000; |
Set_BusA_To = 4'b0000; |
ALU_Op = { 1'b0, IR[5:3] }; |
Save_ALU = 1'b0; |
PreserveC = 1'b0; |
Arith16 = 1'b0; |
IORQ = 1'b0; |
Set_Addr_To = aNone; |
Jump = 1'b0; |
JumpE = 1'b0; |
JumpXY = 1'b0; |
Call = 1'b0; |
RstP = 1'b0; |
LDZ = 1'b0; |
LDW = 1'b0; |
LDSPHL = 1'b0; |
Special_LD = 3'b000; |
ExchangeDH = 1'b0; |
ExchangeRp = 1'b0; |
ExchangeAF = 1'b0; |
ExchangeRS = 1'b0; |
I_DJNZ = 1'b0; |
I_CPL = 1'b0; |
I_CCF = 1'b0; |
I_SCF = 1'b0; |
I_RETN = 1'b0; |
I_BT = 1'b0; |
I_BC = 1'b0; |
I_BTR = 1'b0; |
I_RLD = 1'b0; |
I_RRD = 1'b0; |
I_INRC = 1'b0; |
SetDI = 1'b0; |
SetEI = 1'b0; |
IMode = 2'b11; |
Halt = 1'b0; |
NoRead = 1'b0; |
Write = 1'b0; |
|
|
casex (IR) |
// 8 BIT LOAD GROUP |
8'b01xxxxxx : |
begin |
if (IR[5:0] == 6'b110110) |
Halt = 1'b1; |
else if (IR[2:0] == 3'b110) |
begin |
// LD r,(HL) |
MCycles = 3'b010; |
if (MCycle[0]) |
Set_Addr_To = aXY; |
if (MCycle[1]) |
begin |
Set_BusA_To[2:0] = DDD; |
Read_To_Reg = 1'b1; |
end |
end // if (IR[2:0] == 3'b110) |
else if (IR[5:3] == 3'b110) |
begin |
// LD (HL),r |
MCycles = 3'b010; |
if (MCycle[0]) |
begin |
Set_Addr_To = aXY; |
Set_BusB_To[2:0] = SSS; |
Set_BusB_To[3] = 1'b0; |
end |
if (MCycle[1]) |
Write = 1'b1; |
end // if (IR[5:3] == 3'b110) |
else |
begin |
Set_BusB_To[2:0] = SSS; |
ExchangeRp = 1'b1; |
Set_BusA_To[2:0] = DDD; |
Read_To_Reg = 1'b1; |
end // else: !if(IR[5:3] == 3'b110) |
end // case: 8'b01xxxxxx |
|
8'b00xxx110 : |
begin |
if (IR[5:3] == 3'b110) |
begin |
// LD (HL),n |
MCycles = 3'b011; |
if (MCycle[1]) |
begin |
Inc_PC = 1'b1; |
Set_Addr_To = aXY; |
Set_BusB_To[2:0] = SSS; |
Set_BusB_To[3] = 1'b0; |
end |
if (MCycle[2]) |
Write = 1'b1; |
end // if (IR[5:3] == 3'b110) |
else |
begin |
// LD r,n |
MCycles = 3'b010; |
if (MCycle[1]) |
begin |
Inc_PC = 1'b1; |
Set_BusA_To[2:0] = DDD; |
Read_To_Reg = 1'b1; |
end |
end |
end |
|
8'b00001010 : |
begin |
// LD A,(BC) |
MCycles = 3'b010; |
if (MCycle[0]) |
Set_Addr_To = aBC; |
if (MCycle[1]) |
Read_To_Acc = 1'b1; |
end // case: 8'b00001010 |
|
8'b00011010 : |
begin |
// LD A,(DE) |
MCycles = 3'b010; |
if (MCycle[0]) |
Set_Addr_To = aDE; |
if (MCycle[1]) |
Read_To_Acc = 1'b1; |
end // case: 8'b00011010 |
|
8'b00111010 : |
begin |
if (Mode == 3 ) |
begin |
// LDD A,(HL) |
MCycles = 3'b010; |
if (MCycle[0]) |
Set_Addr_To = aXY; |
if (MCycle[1]) |
begin |
Read_To_Acc = 1'b1; |
IncDec_16 = 4'b1110; |
end |
end |
else |
begin |
// LD A,(nn) |
MCycles = 3'b100; |
if (MCycle[1]) |
begin |
Inc_PC = 1'b1; |
LDZ = 1'b1; |
end |
if (MCycle[2]) |
begin |
Set_Addr_To = aZI; |
Inc_PC = 1'b1; |
end |
if (MCycle[3]) |
begin |
Read_To_Acc = 1'b1; |
end |
end // else: !if(Mode == 3 ) |
end // case: 8'b00111010 |
|
8'b00000010 : |
begin |
// LD (BC),A |
MCycles = 3'b010; |
if (MCycle[0]) |
begin |
Set_Addr_To = aBC; |
Set_BusB_To = 4'b0111; |
end |
if (MCycle[1]) |
begin |
Write = 1'b1; |
end |
end // case: 8'b00000010 |
|
8'b00010010 : |
begin |
// LD (DE),A |
MCycles = 3'b010; |
case (1'b1) // MCycle |
MCycle[0] : |
begin |
Set_Addr_To = aDE; |
Set_BusB_To = 4'b0111; |
end |
MCycle[1] : |
Write = 1'b1; |
default :; |
endcase // case(MCycle) |
end // case: 8'b00010010 |
|
8'b00110010 : |
begin |
if (Mode == 3 ) |
begin |
// LDD (HL),A |
MCycles = 3'b010; |
case (1'b1) // MCycle |
MCycle[0] : |
begin |
Set_Addr_To = aXY; |
Set_BusB_To = 4'b0111; |
end |
MCycle[1] : |
begin |
Write = 1'b1; |
IncDec_16 = 4'b1110; |
end |
default :; |
endcase // case(MCycle) |
|
end |
else |
begin |
// LD (nn),A |
MCycles = 3'b100; |
case (1'b1) // MCycle |
MCycle[1] : |
begin |
Inc_PC = 1'b1; |
LDZ = 1'b1; |
end |
MCycle[2] : |
begin |
Set_Addr_To = aZI; |
Inc_PC = 1'b1; |
Set_BusB_To = 4'b0111; |
end |
MCycle[3] : |
begin |
Write = 1'b1; |
end |
default :; |
endcase |
end // else: !if(Mode == 3 ) |
end // case: 8'b00110010 |
|
|
// 16 BIT LOAD GROUP |
8'b00000001,8'b00010001,8'b00100001,8'b00110001 : |
begin |
// LD dd,nn |
MCycles = 3'b011; |
case (1'b1) // MCycle |
MCycle[1] : |
begin |
Inc_PC = 1'b1; |
Read_To_Reg = 1'b1; |
if (DPAIR == 2'b11 ) |
begin |
Set_BusA_To[3:0] = 4'b1000; |
end |
else |
begin |
Set_BusA_To[2:1] = DPAIR; |
Set_BusA_To[0] = 1'b1; |
end |
end // case: 2 |
|
MCycle[2] : |
begin |
Inc_PC = 1'b1; |
Read_To_Reg = 1'b1; |
if (DPAIR == 2'b11 ) |
begin |
Set_BusA_To[3:0] = 4'b1001; |
end |
else |
begin |
Set_BusA_To[2:1] = DPAIR; |
Set_BusA_To[0] = 1'b0; |
end |
end // case: 3 |
|
default :; |
endcase // case(MCycle) |
end // case: 8'b00000001,8'b00010001,8'b00100001,8'b00110001 |
|
8'b00101010 : |
begin |
if (Mode == 3 ) |
begin |
// LDI A,(HL) |
MCycles = 3'b010; |
case (1'b1) // MCycle |
MCycle[0] : |
Set_Addr_To = aXY; |
MCycle[1] : |
begin |
Read_To_Acc = 1'b1; |
IncDec_16 = 4'b0110; |
end |
|
default :; |
endcase |
end |
else |
begin |
// LD HL,(nn) |
MCycles = 3'b101; |
case (1'b1) // MCycle |
MCycle[1] : |
begin |
Inc_PC = 1'b1; |
LDZ = 1'b1; |
end |
MCycle[2] : |
begin |
Set_Addr_To = aZI; |
Inc_PC = 1'b1; |
LDW = 1'b1; |
end |
MCycle[3] : |
begin |
Set_BusA_To[2:0] = 3'b101; // L |
Read_To_Reg = 1'b1; |
Inc_WZ = 1'b1; |
Set_Addr_To = aZI; |
end |
MCycle[4] : |
begin |
Set_BusA_To[2:0] = 3'b100; // H |
Read_To_Reg = 1'b1; |
end |
default :; |
endcase |
end // else: !if(Mode == 3 ) |
end // case: 8'b00101010 |
|
8'b00100010 : |
begin |
if (Mode == 3 ) |
begin |
// LDI (HL),A |
MCycles = 3'b010; |
case (1'b1) // MCycle |
MCycle[0] : |
begin |
Set_Addr_To = aXY; |
Set_BusB_To = 4'b0111; |
end |
MCycle[1] : |
begin |
Write = 1'b1; |
IncDec_16 = 4'b0110; |
end |
default :; |
endcase |
end |
else |
begin |
// LD (nn),HL |
MCycles = 3'b101; |
case (1'b1) // MCycle |
MCycle[1] : |
begin |
Inc_PC = 1'b1; |
LDZ = 1'b1; |
end |
|
MCycle[2] : |
begin |
Set_Addr_To = aZI; |
Inc_PC = 1'b1; |
LDW = 1'b1; |
Set_BusB_To = 4'b0101; // L |
end |
|
MCycle[3] : |
begin |
Inc_WZ = 1'b1; |
Set_Addr_To = aZI; |
Write = 1'b1; |
Set_BusB_To = 4'b0100; // H |
end |
MCycle[4] : |
Write = 1'b1; |
default :; |
endcase |
end // else: !if(Mode == 3 ) |
end // case: 8'b00100010 |
|
8'b11111001 : |
begin |
// LD SP,HL |
TStates = 3'b110; |
LDSPHL = 1'b1; |
end |
|
8'b11xx0101 : |
begin |
// PUSH qq |
MCycles = 3'b011; |
case (1'b1) // MCycle |
MCycle[0] : |
begin |
TStates = 3'b101; |
IncDec_16 = 4'b1111; |
Set_Addr_To = aSP; |
if (DPAIR == 2'b11 ) |
begin |
Set_BusB_To = 4'b0111; |
end |
else |
begin |
Set_BusB_To[2:1] = DPAIR; |
Set_BusB_To[0] = 1'b0; |
Set_BusB_To[3] = 1'b0; |
end |
end // case: 1 |
|
MCycle[1] : |
begin |
IncDec_16 = 4'b1111; |
Set_Addr_To = aSP; |
if (DPAIR == 2'b11 ) |
begin |
Set_BusB_To = 4'b1011; |
end |
else |
begin |
Set_BusB_To[2:1] = DPAIR; |
Set_BusB_To[0] = 1'b1; |
Set_BusB_To[3] = 1'b0; |
end |
Write = 1'b1; |
end // case: 2 |
|
MCycle[2] : |
Write = 1'b1; |
default :; |
endcase // case(MCycle) |
end // case: 8'b11000101,8'b11010101,8'b11100101,8'b11110101 |
|
8'b11xx0001 : |
begin |
// POP qq |
MCycles = 3'b011; |
case (1'b1) // MCycle |
MCycle[0] : |
Set_Addr_To = aSP; |
MCycle[1] : |
begin |
IncDec_16 = 4'b0111; |
Set_Addr_To = aSP; |
Read_To_Reg = 1'b1; |
if (DPAIR == 2'b11 ) |
begin |
Set_BusA_To[3:0] = 4'b1011; |
end |
else |
begin |
Set_BusA_To[2:1] = DPAIR; |
Set_BusA_To[0] = 1'b1; |
end |
end // case: 2 |
|
MCycle[2] : |
begin |
IncDec_16 = 4'b0111; |
Read_To_Reg = 1'b1; |
if (DPAIR == 2'b11 ) |
begin |
Set_BusA_To[3:0] = 4'b0111; |
end |
else |
begin |
Set_BusA_To[2:1] = DPAIR; |
Set_BusA_To[0] = 1'b0; |
end |
end // case: 3 |
|
default :; |
endcase // case(MCycle) |
end // case: 8'b11000001,8'b11010001,8'b11100001,8'b11110001 |
|
|
// EXCHANGE, BLOCK TRANSFER AND SEARCH GROUP |
8'b11101011 : |
begin |
if (Mode != 3 ) |
begin |
// EX DE,HL |
|
case (1'b1) |
tstate[3] : |
begin |
Set_BusA_To = 4'b0100; |
Set_BusB_To = 4'b0010; |
ExchangeDH = 1'b1; |
end |
|
tstate[4] : |
begin |
Set_BusA_To = 4'b0010; |
ExchangeDH = 1'b1; |
end |
|
default :; |
endcase |
end |
end |
|
8'b00001000 : |
begin |
if (Mode == 3 ) |
begin |
// LD (nn),SP |
MCycles = 3'b101; |
case (1'b1) // MCycle |
MCycle[1] : |
begin |
Inc_PC = 1'b1; |
LDZ = 1'b1; |
end |
|
MCycle[2] : |
begin |
Set_Addr_To = aZI; |
Inc_PC = 1'b1; |
LDW = 1'b1; |
Set_BusB_To = 4'b1000; |
end |
|
MCycle[3] : |
begin |
Inc_WZ = 1'b1; |
Set_Addr_To = aZI; |
Write = 1'b1; |
Set_BusB_To = 4'b1001; |
end |
|
MCycle[4] : |
Write = 1'b1; |
default :; |
endcase |
end |
else if (Mode < 2 ) |
begin |
// EX AF,AF' |
ExchangeAF = 1'b1; |
end |
end // case: 8'b00001000 |
|
8'b11011001 : |
begin |
if (Mode == 3 ) |
begin |
// RETI |
MCycles = 3'b011; |
case (1'b1) // MCycle |
MCycle[0] : |
Set_Addr_To = aSP; |
MCycle[1] : |
begin |
IncDec_16 = 4'b0111; |
Set_Addr_To = aSP; |
LDZ = 1'b1; |
end |
|
MCycle[2] : |
begin |
Jump = 1'b1; |
IncDec_16 = 4'b0111; |
I_RETN = 1'b1; |
SetEI = 1'b1; |
end |
default :; |
endcase |
end |
else if (Mode < 2 ) |
begin |
// EXX |
ExchangeRS = 1'b1; |
end |
end // case: 8'b11011001 |
|
8'b11100011 : |
begin |
if (Mode != 3 ) |
begin |
// EX (SP),HL |
MCycles = 3'b101; |
case (1'b1) // MCycle |
MCycle[0] : |
Set_Addr_To = aSP; |
MCycle[1] : |
begin |
Read_To_Reg = 1'b1; |
Set_BusA_To = 4'b0101; |
Set_BusB_To = 4'b0101; |
Set_Addr_To = aSP; |
end |
MCycle[2] : |
begin |
IncDec_16 = 4'b0111; |
Set_Addr_To = aSP; |
TStates = 3'b100; |
Write = 1'b1; |
end |
MCycle[3] : |
begin |
Read_To_Reg = 1'b1; |
Set_BusA_To = 4'b0100; |
Set_BusB_To = 4'b0100; |
Set_Addr_To = aSP; |
end |
MCycle[4] : |
begin |
IncDec_16 = 4'b1111; |
TStates = 3'b101; |
Write = 1'b1; |
end |
|
default :; |
endcase |
end // if (Mode != 3 ) |
end // case: 8'b11100011 |
|
|
// 8 BIT ARITHMETIC AND LOGICAL GROUP |
8'b10xxxxxx : |
begin |
if (IR[2:0] == 3'b110) |
begin |
// ADD A,(HL) |
// ADC A,(HL) |
// SUB A,(HL) |
// SBC A,(HL) |
// AND A,(HL) |
// OR A,(HL) |
// XOR A,(HL) |
// CP A,(HL) |
MCycles = 3'b010; |
case (1'b1) // MCycle |
MCycle[0] : |
Set_Addr_To = aXY; |
MCycle[1] : |
begin |
Read_To_Reg = 1'b1; |
Save_ALU = 1'b1; |
Set_BusB_To[2:0] = SSS; |
Set_BusA_To[2:0] = 3'b111; |
end |
|
default :; |
endcase // case(MCycle) |
end // if (IR[2:0] == 3'b110) |
else |
begin |
// ADD A,r |
// ADC A,r |
// SUB A,r |
// SBC A,r |
// AND A,r |
// OR A,r |
// XOR A,r |
// CP A,r |
Set_BusB_To[2:0] = SSS; |
Set_BusA_To[2:0] = 3'b111; |
Read_To_Reg = 1'b1; |
Save_ALU = 1'b1; |
end // else: !if(IR[2:0] == 3'b110) |
end // case: 8'b10000000,8'b10000001,8'b10000010,8'b10000011,8'b10000100,8'b10000101,8'b10000111,... |
|
8'b11xxx110 : |
begin |
// ADD A,n |
// ADC A,n |
// SUB A,n |
// SBC A,n |
// AND A,n |
// OR A,n |
// XOR A,n |
// CP A,n |
MCycles = 3'b010; |
if (MCycle[1] ) |
begin |
Inc_PC = 1'b1; |
Read_To_Reg = 1'b1; |
Save_ALU = 1'b1; |
Set_BusB_To[2:0] = SSS; |
Set_BusA_To[2:0] = 3'b111; |
end |
end |
|
8'b00xxx100 : |
begin |
if (IR[5:3] == 3'b110) |
begin |
// INC (HL) |
MCycles = 3'b011; |
case (1'b1) // MCycle |
MCycle[0] : |
Set_Addr_To = aXY; |
MCycle[1] : |
begin |
TStates = 3'b100; |
Set_Addr_To = aXY; |
Read_To_Reg = 1'b1; |
Save_ALU = 1'b1; |
PreserveC = 1'b1; |
ALU_Op = 4'b0000; |
Set_BusB_To = 4'b1010; |
Set_BusA_To[2:0] = DDD; |
end // case: 2 |
|
MCycle[2] : |
Write = 1'b1; |
default :; |
endcase // case(MCycle) |
end // case: 8'b00110100 |
else |
begin |
// INC r |
Set_BusB_To = 4'b1010; |
Set_BusA_To[2:0] = DDD; |
Read_To_Reg = 1'b1; |
Save_ALU = 1'b1; |
PreserveC = 1'b1; |
ALU_Op = 4'b0000; |
end |
end |
|
8'b00xxx101 : |
begin |
if (IR[5:3] == 3'b110) |
begin |
// DEC (HL) |
MCycles = 3'b011; |
case (1'b1) // MCycle |
MCycle[0] : |
Set_Addr_To = aXY; |
MCycle[1] : |
begin |
TStates = 3'b100; |
Set_Addr_To = aXY; |
ALU_Op = 4'b0010; |
Read_To_Reg = 1'b1; |
Save_ALU = 1'b1; |
PreserveC = 1'b1; |
Set_BusB_To = 4'b1010; |
Set_BusA_To[2:0] = DDD; |
end // case: 2 |
|
MCycle[2] : |
Write = 1'b1; |
default :; |
endcase // case(MCycle) |
end |
else |
begin |
// DEC r |
Set_BusB_To = 4'b1010; |
Set_BusA_To[2:0] = DDD; |
Read_To_Reg = 1'b1; |
Save_ALU = 1'b1; |
PreserveC = 1'b1; |
ALU_Op = 4'b0010; |
end |
end |
|
// GENERAL PURPOSE ARITHMETIC AND CPU CONTROL GROUPS |
8'b00100111 : |
begin |
// DAA |
Set_BusA_To[2:0] = 3'b111; |
Read_To_Reg = 1'b1; |
ALU_Op = 4'b1100; |
Save_ALU = 1'b1; |
end |
|
8'b00101111 : |
// CPL |
I_CPL = 1'b1; |
|
8'b00111111 : |
// CCF |
I_CCF = 1'b1; |
|
8'b00110111 : |
// SCF |
I_SCF = 1'b1; |
|
8'b00000000 : |
begin |
if (NMICycle == 1'b1 ) |
begin |
// NMI |
MCycles = 3'b011; |
case (1'b1) // MCycle |
MCycle[0] : |
begin |
TStates = 3'b101; |
IncDec_16 = 4'b1111; |
Set_Addr_To = aSP; |
Set_BusB_To = 4'b1101; |
end |
|
MCycle[1] : |
begin |
TStates = 3'b100; |
Write = 1'b1; |
IncDec_16 = 4'b1111; |
Set_Addr_To = aSP; |
Set_BusB_To = 4'b1100; |
end |
|
MCycle[2] : |
begin |
TStates = 3'b100; |
Write = 1'b1; |
end |
|
default :; |
endcase // case(MCycle) |
|
end |
else if (IntCycle == 1'b1 ) |
begin |
// INT (IM 2) |
MCycles = 3'b101; |
case (1'b1) // MCycle |
MCycle[0] : |
begin |
LDZ = 1'b1; |
TStates = 3'b101; |
IncDec_16 = 4'b1111; |
Set_Addr_To = aSP; |
Set_BusB_To = 4'b1101; |
end |
|
MCycle[1] : |
begin |
TStates = 3'b100; |
Write = 1'b1; |
IncDec_16 = 4'b1111; |
Set_Addr_To = aSP; |
Set_BusB_To = 4'b1100; |
end |
|
MCycle[2] : |
begin |
TStates = 3'b100; |
Write = 1'b1; |
end |
|
MCycle[3] : |
begin |
Inc_PC = 1'b1; |
LDZ = 1'b1; |
end |
|
MCycle[4] : |
Jump = 1'b1; |
default :; |
endcase |
end |
end // case: 8'b00000000 |
|
8'b11110011 : |
// DI |
SetDI = 1'b1; |
|
8'b11111011 : |
// EI |
SetEI = 1'b1; |
|
// 16 BIT ARITHMETIC GROUP |
8'b00001001,8'b00011001,8'b00101001,8'b00111001 : |
begin |
// ADD HL,ss |
MCycles = 3'b011; |
case (1'b1) // MCycle |
MCycle[1] : |
begin |
NoRead = 1'b1; |
ALU_Op = 4'b0000; |
Read_To_Reg = 1'b1; |
Save_ALU = 1'b1; |
Set_BusA_To[2:0] = 3'b101; |
case (IR[5:4]) |
0,1,2 : |
begin |
Set_BusB_To[2:1] = IR[5:4]; |
Set_BusB_To[0] = 1'b1; |
end |
|
default : |
Set_BusB_To = 4'b1000; |
endcase // case(IR[5:4]) |
|
TStates = 3'b100; |
Arith16 = 1'b1; |
end // case: 2 |
|
MCycle[2] : |
begin |
NoRead = 1'b1; |
Read_To_Reg = 1'b1; |
Save_ALU = 1'b1; |
ALU_Op = 4'b0001; |
Set_BusA_To[2:0] = 3'b100; |
case (IR[5:4]) |
0,1,2 : |
Set_BusB_To[2:1] = IR[5:4]; |
default : |
Set_BusB_To = 4'b1001; |
endcase |
Arith16 = 1'b1; |
end // case: 3 |
|
default :; |
endcase // case(MCycle) |
end // case: 8'b00001001,8'b00011001,8'b00101001,8'b00111001 |
|
8'b00000011,8'b00010011,8'b00100011,8'b00110011 : |
begin |
// INC ss |
TStates = 3'b110; |
IncDec_16[3:2] = 2'b01; |
IncDec_16[1:0] = DPAIR; |
end |
|
8'b00001011,8'b00011011,8'b00101011,8'b00111011 : |
begin |
// DEC ss |
TStates = 3'b110; |
IncDec_16[3:2] = 2'b11; |
IncDec_16[1:0] = DPAIR; |
end |
|
// ROTATE AND SHIFT GROUP |
8'b00000111, |
// RLCA |
8'b00010111, |
// RLA |
8'b00001111, |
// RRCA |
8'b00011111 : |
// RRA |
begin |
Set_BusA_To[2:0] = 3'b111; |
ALU_Op = 4'b1000; |
Read_To_Reg = 1'b1; |
Save_ALU = 1'b1; |
end // case: 8'b00000111,... |
|
|
// JUMP GROUP |
8'b11000011 : |
begin |
// JP nn |
MCycles = 3'b011; |
if (MCycle[1]) |
begin |
Inc_PC = 1'b1; |
LDZ = 1'b1; |
end |
|
if (MCycle[2]) |
begin |
Inc_PC = 1'b1; |
Jump = 1'b1; |
end |
|
end // case: 8'b11000011 |
|
8'b11000010,8'b11001010,8'b11010010,8'b11011010,8'b11100010,8'b11101010,8'b11110010,8'b11111010 : |
begin |
if (IR[5] == 1'b1 && Mode == 3 ) |
begin |
case (IR[4:3]) |
2'b00 : |
begin |
// LD ($FF00+C),A |
MCycles = 3'b010; |
case (1'b1) // MCycle |
MCycle[0] : |
begin |
Set_Addr_To = aBC; |
Set_BusB_To = 4'b0111; |
end |
MCycle[1] : |
begin |
Write = 1'b1; |
IORQ = 1'b1; |
end |
|
default :; |
endcase // case(MCycle) |
end // case: 2'b00 |
|
2'b01 : |
begin |
// LD (nn),A |
MCycles = 3'b100; |
case (1'b1) // MCycle |
MCycle[1] : |
begin |
Inc_PC = 1'b1; |
LDZ = 1'b1; |
end |
|
MCycle[2] : |
begin |
Set_Addr_To = aZI; |
Inc_PC = 1'b1; |
Set_BusB_To = 4'b0111; |
end |
|
MCycle[3] : |
Write = 1'b1; |
default :; |
endcase // case(MCycle) |
end // case: default :... |
|
2'b10 : |
begin |
// LD A,($FF00+C) |
MCycles = 3'b010; |
case (1'b1) // MCycle |
MCycle[0] : |
Set_Addr_To = aBC; |
MCycle[1] : |
begin |
Read_To_Acc = 1'b1; |
IORQ = 1'b1; |
end |
default :; |
endcase // case(MCycle) |
end // case: 2'b10 |
|
2'b11 : |
begin |
// LD A,(nn) |
MCycles = 3'b100; |
case (1'b1) // MCycle |
MCycle[1] : |
begin |
Inc_PC = 1'b1; |
LDZ = 1'b1; |
end |
MCycle[2] : |
begin |
Set_Addr_To = aZI; |
Inc_PC = 1'b1; |
end |
MCycle[3] : |
Read_To_Acc = 1'b1; |
default :; |
endcase // case(MCycle) |
end |
endcase |
end |
else |
begin |
// JP cc,nn |
MCycles = 3'b011; |
case (1'b1) // MCycle |
MCycle[1] : |
begin |
Inc_PC = 1'b1; |
LDZ = 1'b1; |
end |
MCycle[2] : |
begin |
Inc_PC = 1'b1; |
if (is_cc_true(F, IR[5:3]) ) |
begin |
Jump = 1'b1; |
end |
end |
|
default :; |
endcase |
end // else: !if(DPAIR == 2'b11 ) |
end // case: 8'b11000010,8'b11001010,8'b11010010,8'b11011010,8'b11100010,8'b11101010,8'b11110010,8'b11111010 |
|
8'b00011000 : |
begin |
if (Mode != 2 ) |
begin |
// JR e |
MCycles = 3'b011; |
case (1'b1) // MCycle |
MCycle[1] : |
Inc_PC = 1'b1; |
MCycle[2] : |
begin |
NoRead = 1'b1; |
JumpE = 1'b1; |
TStates = 3'b101; |
end |
default :; |
endcase |
end // if (Mode != 2 ) |
end // case: 8'b00011000 |
|
8'b00111000 : |
begin |
if (Mode != 2 ) |
begin |
// JR C,e |
MCycles = 3'b011; |
case (1'b1) // MCycle |
MCycle[1] : |
begin |
Inc_PC = 1'b1; |
if (F[Flag_C] == 1'b0 ) |
begin |
MCycles = 3'b010; |
end |
end |
|
MCycle[2] : |
begin |
NoRead = 1'b1; |
JumpE = 1'b1; |
TStates = 3'b101; |
end |
default :; |
endcase |
end // if (Mode != 2 ) |
end // case: 8'b00111000 |
|
8'b00110000 : |
begin |
if (Mode != 2 ) |
begin |
// JR NC,e |
MCycles = 3'b011; |
case (1'b1) // MCycle |
MCycle[1] : |
begin |
Inc_PC = 1'b1; |
if (F[Flag_C] == 1'b1 ) |
begin |
MCycles = 3'b010; |
end |
end |
|
MCycle[2] : |
begin |
NoRead = 1'b1; |
JumpE = 1'b1; |
TStates = 3'b101; |
end |
default :; |
endcase |
end // if (Mode != 2 ) |
end // case: 8'b00110000 |
|
8'b00101000 : |
begin |
if (Mode != 2 ) |
begin |
// JR Z,e |
MCycles = 3'b011; |
case (1'b1) // MCycle |
MCycle[1] : |
begin |
Inc_PC = 1'b1; |
if (F[Flag_Z] == 1'b0 ) |
begin |
MCycles = 3'b010; |
end |
end |
|
MCycle[2] : |
begin |
NoRead = 1'b1; |
JumpE = 1'b1; |
TStates = 3'b101; |
end |
|
default :; |
endcase |
end // if (Mode != 2 ) |
end // case: 8'b00101000 |
|
8'b00100000 : |
begin |
if (Mode != 2 ) |
begin |
// JR NZ,e |
MCycles = 3'b011; |
case (1'b1) // MCycle |
MCycle[1] : |
begin |
Inc_PC = 1'b1; |
if (F[Flag_Z] == 1'b1 ) |
begin |
MCycles = 3'b010; |
end |
end |
MCycle[2] : |
begin |
NoRead = 1'b1; |
JumpE = 1'b1; |
TStates = 3'b101; |
end |
default :; |
endcase |
end // if (Mode != 2 ) |
end // case: 8'b00100000 |
|
8'b11101001 : |
// JP (HL) |
JumpXY = 1'b1; |
|
8'b00010000 : |
begin |
if (Mode == 3 ) |
begin |
I_DJNZ = 1'b1; |
end |
else if (Mode < 2 ) |
begin |
// DJNZ,e |
MCycles = 3'b011; |
case (1'b1) // MCycle |
MCycle[0] : |
begin |
TStates = 3'b101; |
I_DJNZ = 1'b1; |
Set_BusB_To = 4'b1010; |
Set_BusA_To[2:0] = 3'b000; |
Read_To_Reg = 1'b1; |
Save_ALU = 1'b1; |
ALU_Op = 4'b0010; |
end |
MCycle[1] : |
begin |
I_DJNZ = 1'b1; |
Inc_PC = 1'b1; |
end |
MCycle[2] : |
begin |
NoRead = 1'b1; |
JumpE = 1'b1; |
TStates = 3'b101; |
end |
default :; |
endcase |
end // if (Mode < 2 ) |
end // case: 8'b00010000 |
|
|
// CALL AND RETURN GROUP |
8'b11001101 : |
begin |
// CALL nn |
MCycles = 3'b101; |
case (1'b1) // MCycle |
MCycle[1] : |
begin |
Inc_PC = 1'b1; |
LDZ = 1'b1; |
end |
MCycle[2] : |
begin |
IncDec_16 = 4'b1111; |
Inc_PC = 1'b1; |
TStates = 3'b100; |
Set_Addr_To = aSP; |
LDW = 1'b1; |
Set_BusB_To = 4'b1101; |
end |
MCycle[3] : |
begin |
Write = 1'b1; |
IncDec_16 = 4'b1111; |
Set_Addr_To = aSP; |
Set_BusB_To = 4'b1100; |
end |
MCycle[4] : |
begin |
Write = 1'b1; |
Call = 1'b1; |
end |
default :; |
endcase // case(MCycle) |
end // case: 8'b11001101 |
|
8'b11000100,8'b11001100,8'b11010100,8'b11011100,8'b11100100,8'b11101100,8'b11110100,8'b11111100 : |
begin |
if (IR[5] == 1'b0 || Mode != 3 ) |
begin |
// CALL cc,nn |
MCycles = 3'b101; |
case (1'b1) // MCycle |
MCycle[1] : |
begin |
Inc_PC = 1'b1; |
LDZ = 1'b1; |
end |
MCycle[2] : |
begin |
Inc_PC = 1'b1; |
LDW = 1'b1; |
if (is_cc_true(F, IR[5:3]) ) |
begin |
IncDec_16 = 4'b1111; |
Set_Addr_To = aSP; |
TStates = 3'b100; |
Set_BusB_To = 4'b1101; |
end |
else |
begin |
MCycles = 3'b011; |
end // else: !if(is_cc_true(F, IR[5:3]) ) |
end // case: 3 |
|
MCycle[3] : |
begin |
Write = 1'b1; |
IncDec_16 = 4'b1111; |
Set_Addr_To = aSP; |
Set_BusB_To = 4'b1100; |
end |
|
MCycle[4] : |
begin |
Write = 1'b1; |
Call = 1'b1; |
end |
|
default :; |
endcase |
end // if (IR[5] == 1'b0 || Mode != 3 ) |
end // case: 8'b11000100,8'b11001100,8'b11010100,8'b11011100,8'b11100100,8'b11101100,8'b11110100,8'b11111100 |
|
8'b11001001 : |
begin |
// RET |
MCycles = 3'b011; |
case (1'b1) // MCycle |
MCycle[0] : |
begin |
TStates = 3'b101; |
Set_Addr_To = aSP; |
end |
|
MCycle[1] : |
begin |
IncDec_16 = 4'b0111; |
Set_Addr_To = aSP; |
LDZ = 1'b1; |
end |
|
MCycle[2] : |
begin |
Jump = 1'b1; |
IncDec_16 = 4'b0111; |
end |
|
default :; |
endcase // case(MCycle) |
end // case: 8'b11001001 |
|
8'b11000000,8'b11001000,8'b11010000,8'b11011000,8'b11100000,8'b11101000,8'b11110000,8'b11111000 : |
begin |
if (IR[5] == 1'b1 && Mode == 3 ) |
begin |
case (IR[4:3]) |
2'b00 : |
begin |
// LD ($FF00+nn),A |
MCycles = 3'b011; |
case (1'b1) // MCycle |
MCycle[1] : |
begin |
Inc_PC = 1'b1; |
Set_Addr_To = aIOA; |
Set_BusB_To = 4'b0111; |
end |
|
MCycle[2] : |
Write = 1'b1; |
default :; |
endcase // case(MCycle) |
end // case: 2'b00 |
|
2'b01 : |
begin |
// ADD SP,n |
MCycles = 3'b011; |
case (1'b1) // MCycle |
MCycle[1] : |
begin |
ALU_Op = 4'b0000; |
Inc_PC = 1'b1; |
Read_To_Reg = 1'b1; |
Save_ALU = 1'b1; |
Set_BusA_To = 4'b1000; |
Set_BusB_To = 4'b0110; |
end |
|
MCycle[2] : |
begin |
NoRead = 1'b1; |
Read_To_Reg = 1'b1; |
Save_ALU = 1'b1; |
ALU_Op = 4'b0001; |
Set_BusA_To = 4'b1001; |
Set_BusB_To = 4'b1110; // Incorrect unsigned !!!!!!!!!!!!!!!!!!!!! |
end |
|
default :; |
endcase // case(MCycle) |
end // case: 2'b01 |
|
2'b10 : |
begin |
// LD A,($FF00+nn) |
MCycles = 3'b011; |
case (1'b1) // MCycle |
MCycle[1] : |
begin |
Inc_PC = 1'b1; |
Set_Addr_To = aIOA; |
end |
|
MCycle[2] : |
Read_To_Acc = 1'b1; |
default :; |
endcase // case(MCycle) |
end // case: 2'b10 |
|
2'b11 : |
begin |
// LD HL,SP+n -- Not correct !!!!!!!!!!!!!!!!!!! |
MCycles = 3'b101; |
case (1'b1) // MCycle |
MCycle[1] : |
begin |
Inc_PC = 1'b1; |
LDZ = 1'b1; |
end |
|
MCycle[2] : |
begin |
Set_Addr_To = aZI; |
Inc_PC = 1'b1; |
LDW = 1'b1; |
end |
|
MCycle[3] : |
begin |
Set_BusA_To[2:0] = 3'b101; // L |
Read_To_Reg = 1'b1; |
Inc_WZ = 1'b1; |
Set_Addr_To = aZI; |
end |
|
MCycle[4] : |
begin |
Set_BusA_To[2:0] = 3'b100; // H |
Read_To_Reg = 1'b1; |
end |
|
default :; |
endcase // case(MCycle) |
end // case: 2'b11 |
|
endcase // case(IR[4:3]) |
|
end |
else |
begin |
// RET cc |
MCycles = 3'b011; |
case (1'b1) // MCycle |
MCycle[0] : |
begin |
if (is_cc_true(F, IR[5:3]) ) |
begin |
Set_Addr_To = aSP; |
end |
else |
begin |
MCycles = 3'b001; |
end |
TStates = 3'b101; |
end // case: 1 |
|
MCycle[1] : |
begin |
IncDec_16 = 4'b0111; |
Set_Addr_To = aSP; |
LDZ = 1'b1; |
end |
MCycle[2] : |
begin |
Jump = 1'b1; |
IncDec_16 = 4'b0111; |
end |
default :; |
endcase |
end // else: !if(IR[5] == 1'b1 && Mode == 3 ) |
end // case: 8'b11000000,8'b11001000,8'b11010000,8'b11011000,8'b11100000,8'b11101000,8'b11110000,8'b11111000 |
|
8'b11000111,8'b11001111,8'b11010111,8'b11011111,8'b11100111,8'b11101111,8'b11110111,8'b11111111 : |
begin |
// RST p |
MCycles = 3'b011; |
case (1'b1) // MCycle |
MCycle[0] : |
begin |
TStates = 3'b101; |
IncDec_16 = 4'b1111; |
Set_Addr_To = aSP; |
Set_BusB_To = 4'b1101; |
end |
|
MCycle[1] : |
begin |
Write = 1'b1; |
IncDec_16 = 4'b1111; |
Set_Addr_To = aSP; |
Set_BusB_To = 4'b1100; |
end |
|
MCycle[2] : |
begin |
Write = 1'b1; |
RstP = 1'b1; |
end |
|
default :; |
endcase // case(MCycle) |
end // case: 8'b11000111,8'b11001111,8'b11010111,8'b11011111,8'b11100111,8'b11101111,8'b11110111,8'b11111111 |
|
// INPUT AND OUTPUT GROUP |
8'b11011011 : |
begin |
if (Mode != 3 ) |
begin |
// IN A,(n) |
MCycles = 3'b011; |
case (1'b1) // MCycle |
MCycle[1] : |
begin |
Inc_PC = 1'b1; |
Set_Addr_To = aIOA; |
end |
|
MCycle[2] : |
begin |
Read_To_Acc = 1'b1; |
IORQ = 1'b1; |
end |
|
default :; |
endcase |
end // if (Mode != 3 ) |
end // case: 8'b11011011 |
|
8'b11010011 : |
begin |
if (Mode != 3 ) |
begin |
// OUT (n),A |
MCycles = 3'b011; |
case (1'b1) // MCycle |
MCycle[1] : |
begin |
Inc_PC = 1'b1; |
Set_Addr_To = aIOA; |
Set_BusB_To = 4'b0111; |
end |
|
MCycle[2] : |
begin |
Write = 1'b1; |
IORQ = 1'b1; |
end |
|
default :; |
endcase |
end // if (Mode != 3 ) |
end // case: 8'b11010011 |
|
|
//---------------------------------------------------------------------------- |
//---------------------------------------------------------------------------- |
// MULTIBYTE INSTRUCTIONS |
//---------------------------------------------------------------------------- |
//---------------------------------------------------------------------------- |
|
8'b11001011 : |
begin |
if (Mode != 2 ) |
begin |
Prefix = 2'b01; |
end |
end |
|
8'b11101101 : |
begin |
if (Mode < 2 ) |
begin |
Prefix = 2'b10; |
end |
end |
|
8'b11011101,8'b11111101 : |
begin |
if (Mode < 2 ) |
begin |
Prefix = 2'b11; |
end |
end |
|
endcase // case(IR) |
|
|
end // always @ (IR, ISet, MCycle, F, NMICycle, IntCycle) |
|
assign output_vector = { MCycles, |
TStates, |
Prefix, |
Inc_PC, |
Inc_WZ, |
IncDec_16, |
Read_To_Reg, |
Read_To_Acc, |
Set_BusA_To, |
Set_BusB_To, |
ALU_Op, |
Save_ALU, |
PreserveC, |
Arith16, |
Set_Addr_To, |
IORQ, |
Jump, |
JumpE, |
JumpXY, |
Call, |
RstP, |
LDZ, |
LDW, |
LDSPHL, |
Special_LD, |
ExchangeDH, |
ExchangeRp, |
ExchangeAF, |
ExchangeRS, |
I_DJNZ, |
I_CPL, |
I_CCF, |
I_SCF, |
I_RETN, |
I_BT, |
I_BC, |
I_BTR, |
I_RLD, |
I_RRD, |
I_INRC, |
SetDI, |
SetEI, |
IMode, |
Halt, |
NoRead, |
Write }; |
|
|
// synopsys dc_script_begin |
// set_attribute current_design "revision" "$Id: tv80_mcode_base.v,v 1.1.2.2 2004-12-16 00:46:34 ghutchis Exp $" -type string -quiet |
// synopsys dc_script_end |
endmodule // T80_MCode |
/core/tv80_mcode.v
0,0 → 1,321
// |
// TV80 8-Bit Microprocessor Core |
// Based on the VHDL T80 core by Daniel Wallner (jesus@opencores.org) |
// |
// Copyright (c) 2004 Guy Hutchison (ghutchis@opencores.org) |
// |
// Permission is hereby granted, free of charge, to any person obtaining a |
// copy of this software and associated documentation files (the "Software"), |
// to deal in the Software without restriction, including without limitation |
// the rights to use, copy, modify, merge, publish, distribute, sublicense, |
// and/or sell copies of the Software, and to permit persons to whom the |
// Software is furnished to do so, subject to the following conditions: |
// |
// The above copyright notice and this permission notice shall be included |
// in all copies or substantial portions of the Software. |
// |
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, |
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. |
// IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY |
// CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, |
// TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE |
// SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. |
|
module tv80_mcode |
(/*AUTOARG*/ |
// Outputs |
MCycles, TStates, Prefix, Inc_PC, Inc_WZ, IncDec_16, Read_To_Reg, |
Read_To_Acc, Set_BusA_To, Set_BusB_To, ALU_Op, Save_ALU, PreserveC, |
Arith16, Set_Addr_To, IORQ, Jump, JumpE, JumpXY, Call, RstP, LDZ, |
LDW, LDSPHL, Special_LD, ExchangeDH, ExchangeRp, ExchangeAF, |
ExchangeRS, I_DJNZ, I_CPL, I_CCF, I_SCF, I_RETN, I_BT, I_BC, I_BTR, |
I_RLD, I_RRD, I_INRC, SetDI, SetEI, IMode, Halt, NoRead, Write, |
// Inputs |
IR, ISet, MCycle, F, tstate, NMICycle, IntCycle |
); |
|
parameter Mode = 0; |
parameter Flag_C = 0; |
parameter Flag_N = 1; |
parameter Flag_P = 2; |
parameter Flag_X = 3; |
parameter Flag_H = 4; |
parameter Flag_Y = 5; |
parameter Flag_Z = 6; |
parameter Flag_S = 7; |
|
input [7:0] IR; |
input [1:0] ISet ; |
input [6:0] MCycle ; |
input [7:0] F ; |
input [6:0] tstate; |
input NMICycle ; |
input IntCycle ; |
output [2:0] MCycles ; |
output [2:0] TStates ; |
output [1:0] Prefix ; // None,BC,ED,DD/FD |
output Inc_PC ; |
output Inc_WZ ; |
output [3:0] IncDec_16 ; // BC,DE,HL,SP 0 is inc |
output Read_To_Reg ; |
output Read_To_Acc ; |
output [3:0] Set_BusA_To ; // B,C,D,E,H,L,DI/DB,A,SP(L),SP(M),0,F |
output [3:0] Set_BusB_To ; // B,C,D,E,H,L,DI,A,SP(L),SP(M),1,F,PC(L),PC(M),0 |
output [3:0] ALU_Op ; |
output Save_ALU ; |
output PreserveC ; |
output Arith16 ; |
output [2:0] Set_Addr_To ; // aNone,aXY,aIOA,aSP,aBC,aDE,aZI |
output IORQ ; |
output Jump ; |
output JumpE ; |
output JumpXY ; |
output Call ; |
output RstP ; |
output LDZ ; |
output LDW ; |
output LDSPHL ; |
output [2:0] Special_LD ; // A,I;A,R;I,A;R,A;None |
output ExchangeDH ; |
output ExchangeRp ; |
output ExchangeAF ; |
output ExchangeRS ; |
output I_DJNZ ; |
output I_CPL ; |
output I_CCF ; |
output I_SCF ; |
output I_RETN ; |
output I_BT ; |
output I_BC ; |
output I_BTR ; |
output I_RLD ; |
output I_RRD ; |
output I_INRC ; |
output SetDI ; |
output SetEI ; |
output [1:0] IMode ; |
output Halt ; |
output NoRead ; |
output Write ; |
|
// regs |
reg [2:0] MCycles ; |
reg [2:0] TStates ; |
reg [1:0] Prefix ; // None,BC,ED,DD/FD |
reg Inc_PC ; |
reg Inc_WZ ; |
reg [3:0] IncDec_16 ; // BC,DE,HL,SP 0 is inc |
reg Read_To_Reg ; |
reg Read_To_Acc ; |
reg [3:0] Set_BusA_To ; // B,C,D,E,H,L,DI/DB,A,SP(L),SP(M),0,F |
reg [3:0] Set_BusB_To ; // B,C,D,E,H,L,DI,A,SP(L),SP(M),1,F,PC(L),PC(M),0 |
reg [3:0] ALU_Op ; |
reg Save_ALU ; |
reg PreserveC ; |
reg Arith16 ; |
reg [2:0] Set_Addr_To ; // aNone,aXY,aIOA,aSP,aBC,aDE,aZI |
reg IORQ ; |
reg Jump ; |
reg JumpE ; |
reg JumpXY ; |
reg Call ; |
reg RstP ; |
reg LDZ ; |
reg LDW ; |
reg LDSPHL ; |
reg [2:0] Special_LD ; // A,I;A,R;I,A;R,A;None |
reg ExchangeDH ; |
reg ExchangeRp ; |
reg ExchangeAF ; |
reg ExchangeRS ; |
reg I_DJNZ ; |
reg I_CPL ; |
reg I_CCF ; |
reg I_SCF ; |
reg I_RETN ; |
reg I_BT ; |
reg I_BC ; |
reg I_BTR ; |
reg I_RLD ; |
reg I_RRD ; |
reg I_INRC ; |
reg SetDI ; |
reg SetEI ; |
reg [1:0] IMode ; |
reg Halt ; |
reg NoRead ; |
reg Write ; |
|
parameter aNone = 3'b111; |
parameter aBC = 3'b000; |
parameter aDE = 3'b001; |
parameter aXY = 3'b010; |
parameter aIOA = 3'b100; |
parameter aSP = 3'b101; |
parameter aZI = 3'b110; |
|
|
reg [2:0] DDD; |
reg [2:0] SSS; |
reg [1:0] DPAIR; |
|
wire [67:0] vec_base, vec_cb, vec_ed; |
reg [67:0] vec_final; |
|
// instruction decoders |
tv80_mcode_base #(Mode) dec_base |
( |
// Outputs |
.output_vector (vec_base), |
// Inputs |
.IR (IR), |
.MCycle (MCycle), |
.tstate (tstate), |
.F (F), |
.NMICycle (NMICycle), |
.IntCycle (IntCycle)); |
|
tv80_mcode_cb #(Mode) dec_cb |
( |
// Outputs |
.output_vector (vec_cb), |
// Inputs |
.IR (IR), |
.MCycle (MCycle)); |
|
tv80_mcode_ed #(Mode) dec_ed |
( |
// Outputs |
.output_vector (vec_ed), |
// Inputs |
.IR (IR), |
.MCycle (MCycle)); |
|
always @ (/*AUTOSENSE*/IR or ISet or MCycle or SSS or vec_base |
or vec_cb or vec_ed) |
begin |
case (ISet) |
2'b00 : vec_final = vec_base; |
2'b01 : vec_final = vec_cb; |
default : vec_final = vec_ed; |
endcase // case(ISet) |
|
{ MCycles, |
TStates, |
Prefix, |
Inc_PC, |
Inc_WZ, |
IncDec_16, |
Read_To_Reg, |
Read_To_Acc, |
Set_BusA_To, |
Set_BusB_To, |
ALU_Op, |
Save_ALU, |
PreserveC, |
Arith16, |
Set_Addr_To, |
IORQ, |
Jump, |
JumpE, |
JumpXY, |
Call, |
RstP, |
LDZ, |
LDW, |
LDSPHL, |
Special_LD, |
ExchangeDH, |
ExchangeRp, |
ExchangeAF, |
ExchangeRS, |
I_DJNZ, |
I_CPL, |
I_CCF, |
I_SCF, |
I_RETN, |
I_BT, |
I_BC, |
I_BTR, |
I_RLD, |
I_RRD, |
I_INRC, |
SetDI, |
SetEI, |
IMode, |
Halt, |
NoRead, |
Write } = vec_final; |
|
if (Mode == 1 ) |
begin |
if (MCycle[0] ) |
begin |
//TStates = 3'b100; |
end |
else |
begin |
TStates = 3'b011; |
end |
end |
|
if (Mode == 3 ) |
begin |
if (MCycle[0] ) |
begin |
//TStates = 3'b100; |
end |
else |
begin |
TStates = 3'b100; |
end |
end |
|
if (Mode < 2 ) |
begin |
if (MCycle[5] ) |
begin |
Inc_PC = 1'b1; |
if (Mode == 1 ) |
begin |
Set_Addr_To = aXY; |
TStates = 3'b100; |
Set_BusB_To[2:0] = SSS; |
Set_BusB_To[3] = 1'b0; |
end |
if (IR == 8'b00110110 || IR == 8'b11001011 ) |
begin |
Set_Addr_To = aNone; |
end |
end |
if (MCycle[6] ) |
begin |
if (Mode == 0 ) |
begin |
TStates = 3'b101; |
end |
if (ISet != 2'b01 ) |
begin |
Set_Addr_To = aXY; |
end |
Set_BusB_To[2:0] = SSS; |
Set_BusB_To[3] = 1'b0; |
if (IR == 8'b00110110 || ISet == 2'b01 ) |
begin |
// LD (HL),n |
Inc_PC = 1'b1; |
end |
else |
begin |
NoRead = 1'b1; |
end |
end |
end // if (Mode < 2 ) |
|
end // always @ (IR, ISet, MCycle, F, NMICycle, IntCycle) |
|
// synopsys dc_script_begin |
// set_attribute current_design "revision" "$Id: tv80_mcode.v,v 1.5.4.2 2004-12-16 00:46:29 ghutchis Exp $" -type string -quiet |
// synopsys dc_script_end |
endmodule // T80_MCode |
/core/tv80_core.v
0,0 → 1,1329
// |
// TV80 8-Bit Microprocessor Core |
// Based on the VHDL T80 core by Daniel Wallner (jesus@opencores.org) |
// |
// Copyright (c) 2004 Guy Hutchison (ghutchis@opencores.org) |
// |
// Permission is hereby granted, free of charge, to any person obtaining a |
// copy of this software and associated documentation files (the "Software"), |
// to deal in the Software without restriction, including without limitation |
// the rights to use, copy, modify, merge, publish, distribute, sublicense, |
// and/or sell copies of the Software, and to permit persons to whom the |
// Software is furnished to do so, subject to the following conditions: |
// |
// The above copyright notice and this permission notice shall be included |
// in all copies or substantial portions of the Software. |
// |
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, |
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. |
// IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY |
// CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, |
// TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE |
// SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. |
|
module tv80_core (/*AUTOARG*/ |
// Outputs |
m1_n, iorq, no_read, write, rfsh_n, halt_n, busak_n, A, do, mc, ts, |
intcycle_n, IntE, stop, |
// Inputs |
reset_n, clk, cen, wait_n, int_n, nmi_n, busrq_n, dinst, di |
); |
// Beginning of automatic inputs (from unused autoinst inputs) |
// End of automatics |
|
parameter Mode = 1; // 0 => Z80, 1 => Fast Z80, 2 => 8080, 3 => GB |
parameter IOWait = 1; // 0 => Single cycle I/O, 1 => Std I/O cycle |
parameter Flag_C = 0; |
parameter Flag_N = 1; |
parameter Flag_P = 2; |
parameter Flag_X = 3; |
parameter Flag_H = 4; |
parameter Flag_Y = 5; |
parameter Flag_Z = 6; |
parameter Flag_S = 7; |
|
input reset_n; |
input clk; |
input cen; |
input wait_n; |
input int_n; |
input nmi_n; |
input busrq_n; |
output m1_n; |
output iorq; |
output no_read; |
output write; |
output rfsh_n; |
output halt_n; |
output busak_n; |
output [15:0] A; |
input [7:0] dinst; |
input [7:0] di; |
output [7:0] do; |
output [6:0] mc; |
output [6:0] ts; |
output intcycle_n; |
output IntE; |
output stop; |
|
reg m1_n; |
reg iorq; |
reg rfsh_n; |
reg halt_n; |
reg busak_n; |
reg [15:0] A; |
reg [7:0] do; |
reg [6:0] mc; |
reg [6:0] ts; |
reg intcycle_n; |
reg IntE; |
reg stop; |
|
parameter aNone = 3'b111; |
parameter aBC = 3'b000; |
parameter aDE = 3'b001; |
parameter aXY = 3'b010; |
parameter aIOA = 3'b100; |
parameter aSP = 3'b101; |
parameter aZI = 3'b110; |
|
// Registers |
reg [7:0] ACC, F; |
reg [7:0] Ap, Fp; |
reg [7:0] I; |
reg [7:0] R; |
reg [15:0] SP, PC; |
reg [7:0] RegDIH; |
reg [7:0] RegDIL; |
wire [15:0] RegBusA; |
wire [15:0] RegBusB; |
wire [15:0] RegBusC; |
reg [2:0] RegAddrA_r; |
reg [2:0] RegAddrA; |
reg [2:0] RegAddrB_r; |
reg [2:0] RegAddrB; |
reg [2:0] RegAddrC; |
reg RegWEH; |
reg RegWEL; |
reg Alternate; |
|
// Help Registers |
reg [15:0] TmpAddr; // Temporary address register |
reg [7:0] IR; // Instruction register |
reg [1:0] ISet; // Instruction set selector |
reg [15:0] RegBusA_r; |
|
reg [15:0] ID16; |
reg [7:0] Save_Mux; |
|
reg [6:0] tstate; |
reg [6:0] mcycle; |
reg last_mcycle, last_tstate; |
reg IntE_FF1; |
reg IntE_FF2; |
reg Halt_FF; |
reg BusReq_s; |
reg BusAck; |
reg ClkEn; |
reg NMI_s; |
reg INT_s; |
reg [1:0] IStatus; |
|
reg [7:0] DI_Reg; |
reg T_Res; |
reg [1:0] XY_State; |
reg [2:0] Pre_XY_F_M; |
reg NextIs_XY_Fetch; |
reg XY_Ind; |
reg No_BTR; |
reg BTR_r; |
reg Auto_Wait; |
reg Auto_Wait_t1; |
reg Auto_Wait_t2; |
reg IncDecZ; |
|
// ALU signals |
reg [7:0] BusB, NextBusB; |
reg [7:0] BusA, NextBusA; |
wire [7:0] ALU_Q; |
wire [7:0] F_Out; |
|
// Registered micro code outputs |
reg [4:0] Read_To_Reg_r; |
reg Arith16_r; |
reg Z16_r; |
reg [3:0] ALU_Op_r; |
reg Save_ALU_r; |
reg PreserveC_r; |
reg [2:0] mcycles; |
|
// Micro code outputs |
wire [2:0] mcycles_d; |
wire [2:0] tstates; |
reg IntCycle; |
reg NMICycle; |
wire Inc_PC; |
wire Inc_WZ; |
wire [3:0] IncDec_16; |
wire [1:0] Prefix; |
wire Read_To_Acc; |
wire Read_To_Reg; |
wire [3:0] Set_BusB_To; |
wire [3:0] Set_BusA_To; |
wire [3:0] ALU_Op; |
wire Save_ALU; |
wire PreserveC; |
wire Arith16; |
wire [2:0] Set_Addr_To; |
wire Jump; |
wire JumpE; |
wire JumpXY; |
wire Call; |
wire RstP; |
wire LDZ; |
wire LDW; |
wire LDSPHL; |
wire iorq_i; |
wire [2:0] Special_LD; |
wire ExchangeDH; |
wire ExchangeRp; |
wire ExchangeAF; |
wire ExchangeRS; |
wire I_DJNZ; |
wire I_CPL; |
wire I_CCF; |
wire I_SCF; |
wire I_RETN; |
wire I_BT; |
wire I_BC; |
wire I_BTR; |
wire I_RLD; |
wire I_RRD; |
wire I_INRC; |
wire SetDI; |
wire SetEI; |
wire [1:0] IMode; |
wire Halt; |
|
reg [15:0] PC16; |
reg [15:0] PC16_B; |
reg [15:0] SP16, SP16_A, SP16_B; |
reg [15:0] ID16_B; |
reg Oldnmi_n; |
|
tv80_mcode #(Mode, Flag_C, Flag_N, Flag_P, Flag_X, Flag_H, Flag_Y, Flag_Z, Flag_S) i_mcode |
( |
.IR (IR), |
.ISet (ISet), |
.MCycle (mcycle), |
.tstate (tstate), |
.F (F), |
.NMICycle (NMICycle), |
.IntCycle (IntCycle), |
.MCycles (mcycles_d), |
.TStates (tstates), |
.Prefix (Prefix), |
.Inc_PC (Inc_PC), |
.Inc_WZ (Inc_WZ), |
.IncDec_16 (IncDec_16), |
.Read_To_Acc (Read_To_Acc), |
.Read_To_Reg (Read_To_Reg), |
.Set_BusB_To (Set_BusB_To), |
.Set_BusA_To (Set_BusA_To), |
.ALU_Op (ALU_Op), |
.Save_ALU (Save_ALU), |
.PreserveC (PreserveC), |
.Arith16 (Arith16), |
.Set_Addr_To (Set_Addr_To), |
.IORQ (iorq_i), |
.Jump (Jump), |
.JumpE (JumpE), |
.JumpXY (JumpXY), |
.Call (Call), |
.RstP (RstP), |
.LDZ (LDZ), |
.LDW (LDW), |
.LDSPHL (LDSPHL), |
.Special_LD (Special_LD), |
.ExchangeDH (ExchangeDH), |
.ExchangeRp (ExchangeRp), |
.ExchangeAF (ExchangeAF), |
.ExchangeRS (ExchangeRS), |
.I_DJNZ (I_DJNZ), |
.I_CPL (I_CPL), |
.I_CCF (I_CCF), |
.I_SCF (I_SCF), |
.I_RETN (I_RETN), |
.I_BT (I_BT), |
.I_BC (I_BC), |
.I_BTR (I_BTR), |
.I_RLD (I_RLD), |
.I_RRD (I_RRD), |
.I_INRC (I_INRC), |
.SetDI (SetDI), |
.SetEI (SetEI), |
.IMode (IMode), |
.Halt (Halt), |
.NoRead (no_read), |
.Write (write) |
); |
|
tv80_alu #(Mode, Flag_C, Flag_N, Flag_P, Flag_X, Flag_H, Flag_Y, Flag_Z, Flag_S) i_alu |
( |
.Arith16 (Arith16_r), |
.Z16 (Z16_r), |
.ALU_Op (ALU_Op_r), |
.IR (IR[5:0]), |
.ISet (ISet), |
.BusA (BusA), |
.BusB (BusB), |
.F_In (F), |
.Q (ALU_Q), |
.F_Out (F_Out) |
); |
|
function [6:0] number_to_bitvec; |
input [2:0] num; |
begin |
case (num) |
1 : number_to_bitvec = 7'b0000001; |
2 : number_to_bitvec = 7'b0000010; |
3 : number_to_bitvec = 7'b0000100; |
4 : number_to_bitvec = 7'b0001000; |
5 : number_to_bitvec = 7'b0010000; |
6 : number_to_bitvec = 7'b0100000; |
7 : number_to_bitvec = 7'b1000000; |
default : number_to_bitvec = 7'bx; |
endcase // case(num) |
end |
endfunction // number_to_bitvec |
|
always @(/*AUTOSENSE*/mcycle or mcycles or tstate or tstates) |
begin |
case (mcycles) |
1 : last_mcycle = mcycle[0]; |
2 : last_mcycle = mcycle[1]; |
3 : last_mcycle = mcycle[2]; |
4 : last_mcycle = mcycle[3]; |
5 : last_mcycle = mcycle[4]; |
6 : last_mcycle = mcycle[5]; |
7 : last_mcycle = mcycle[6]; |
default : last_mcycle = 1'bx; |
endcase // case(mcycles) |
|
case (tstates) |
0 : last_tstate = tstate[0]; |
1 : last_tstate = tstate[1]; |
2 : last_tstate = tstate[2]; |
3 : last_tstate = tstate[3]; |
4 : last_tstate = tstate[4]; |
5 : last_tstate = tstate[5]; |
6 : last_tstate = tstate[6]; |
default : last_tstate = 1'bx; |
endcase |
end // always @ (... |
|
|
always @(/*AUTOSENSE*/ALU_Q or BusAck or BusB or DI_Reg |
or ExchangeRp or IR or Save_ALU_r or Set_Addr_To or XY_Ind |
or XY_State or cen or last_tstate or mcycle) |
begin |
ClkEn = cen && ~ BusAck; |
|
if (last_tstate) |
T_Res = 1'b1; |
else T_Res = 1'b0; |
|
if (XY_State != 2'b00 && XY_Ind == 1'b0 && |
((Set_Addr_To == aXY) || |
(mcycle[0] && IR == 8'b11001011) || |
(mcycle[0] && IR == 8'b00110110))) |
NextIs_XY_Fetch = 1'b1; |
else |
NextIs_XY_Fetch = 1'b0; |
|
if (ExchangeRp) |
Save_Mux = BusB; |
else if (!Save_ALU_r) |
Save_Mux = DI_Reg; |
else |
Save_Mux = ALU_Q; |
end // always @ * |
|
always @ (posedge clk) |
begin |
if (reset_n == 1'b0 ) |
begin |
PC <= #1 0; // Program Counter |
A <= #1 0; |
TmpAddr <= #1 0; |
IR <= #1 8'b00000000; |
ISet <= #1 2'b00; |
XY_State <= #1 2'b00; |
IStatus <= #1 2'b00; |
mcycles <= #1 3'b000; |
do <= #1 8'b00000000; |
|
ACC <= #1 8'hFF; |
F <= #1 8'hFF; |
Ap <= #1 8'hFF; |
Fp <= #1 8'hFF; |
I <= #1 0; |
R <= #1 0; |
SP <= #1 16'hFFFF; |
Alternate <= #1 1'b0; |
|
Read_To_Reg_r <= #1 5'b00000; |
Arith16_r <= #1 1'b0; |
BTR_r <= #1 1'b0; |
Z16_r <= #1 1'b0; |
ALU_Op_r <= #1 4'b0000; |
Save_ALU_r <= #1 1'b0; |
PreserveC_r <= #1 1'b0; |
XY_Ind <= #1 1'b0; |
end |
else |
begin |
|
if (ClkEn == 1'b1 ) |
begin |
|
ALU_Op_r <= #1 4'b0000; |
Save_ALU_r <= #1 1'b0; |
Read_To_Reg_r <= #1 5'b00000; |
|
mcycles <= #1 mcycles_d; |
|
if (IMode != 2'b11 ) |
begin |
IStatus <= #1 IMode; |
end |
|
Arith16_r <= #1 Arith16; |
PreserveC_r <= #1 PreserveC; |
if (ISet == 2'b10 && ALU_Op[2] == 1'b0 && ALU_Op[0] == 1'b1 && mcycle[2] ) |
begin |
Z16_r <= #1 1'b1; |
end |
else |
begin |
Z16_r <= #1 1'b0; |
end |
|
if (mcycle[0] && (tstate[1] | tstate[2] | tstate[3] )) |
begin |
// mcycle == 1 && tstate == 1, 2, || 3 |
|
if (tstate[2] && wait_n == 1'b1 ) |
begin |
if (Mode < 2 ) |
begin |
A[7:0] <= #1 R; |
A[15:8] <= #1 I; |
R[6:0] <= #1 R[6:0] + 1; |
end |
|
if (Jump == 1'b0 && Call == 1'b0 && NMICycle == 1'b0 && IntCycle == 1'b0 && ~ (Halt_FF == 1'b1 || Halt == 1'b1) ) |
begin |
PC <= #1 PC16; |
end |
|
if (IntCycle == 1'b1 && IStatus == 2'b01 ) |
begin |
IR <= #1 8'b11111111; |
end |
else if (Halt_FF == 1'b1 || (IntCycle == 1'b1 && IStatus == 2'b10) || NMICycle == 1'b1 ) |
begin |
IR <= #1 8'b00000000; |
end |
else |
begin |
IR <= #1 dinst; |
end |
|
ISet <= #1 2'b00; |
if (Prefix != 2'b00 ) |
begin |
if (Prefix == 2'b11 ) |
begin |
if (IR[5] == 1'b1 ) |
begin |
XY_State <= #1 2'b10; |
end |
else |
begin |
XY_State <= #1 2'b01; |
end |
end |
else |
begin |
if (Prefix == 2'b10 ) |
begin |
XY_State <= #1 2'b00; |
XY_Ind <= #1 1'b0; |
end |
ISet <= #1 Prefix; |
end |
end |
else |
begin |
XY_State <= #1 2'b00; |
XY_Ind <= #1 1'b0; |
end |
end // if (tstate == 2 && wait_n == 1'b1 ) |
|
|
end |
else |
begin |
// either (mcycle > 1) OR (mcycle == 1 AND tstate > 3) |
|
if (mcycle[5] ) |
begin |
XY_Ind <= #1 1'b1; |
if (Prefix == 2'b01 ) |
begin |
ISet <= #1 2'b01; |
end |
end |
|
if (T_Res == 1'b1 ) |
begin |
BTR_r <= #1 (I_BT || I_BC || I_BTR) && ~ No_BTR; |
if (Jump == 1'b1 ) |
begin |
A[15:8] <= #1 DI_Reg; |
A[7:0] <= #1 TmpAddr[7:0]; |
PC[15:8] <= #1 DI_Reg; |
PC[7:0] <= #1 TmpAddr[7:0]; |
end |
else if (JumpXY == 1'b1 ) |
begin |
A <= #1 RegBusC; |
PC <= #1 RegBusC; |
end else if (Call == 1'b1 || RstP == 1'b1 ) |
begin |
A <= #1 TmpAddr; |
PC <= #1 TmpAddr; |
end |
else if (last_mcycle && NMICycle == 1'b1 ) |
begin |
A <= #1 16'b0000000001100110; |
PC <= #1 16'b0000000001100110; |
end |
else if (mcycle[2] && IntCycle == 1'b1 && IStatus == 2'b10 ) |
begin |
A[15:8] <= #1 I; |
A[7:0] <= #1 TmpAddr[7:0]; |
PC[15:8] <= #1 I; |
PC[7:0] <= #1 TmpAddr[7:0]; |
end |
else |
begin |
case (Set_Addr_To) |
aXY : |
begin |
if (XY_State == 2'b00 ) |
begin |
A <= #1 RegBusC; |
end |
else |
begin |
if (NextIs_XY_Fetch == 1'b1 ) |
begin |
A <= #1 PC; |
end |
else |
begin |
A <= #1 TmpAddr; |
end |
end // else: !if(XY_State == 2'b00 ) |
end // case: aXY |
|
aIOA : |
begin |
if (Mode == 3 ) |
begin |
// Memory map I/O on GBZ80 |
A[15:8] <= #1 8'hFF; |
end |
else if (Mode == 2 ) |
begin |
// Duplicate I/O address on 8080 |
A[15:8] <= #1 DI_Reg; |
end |
else |
begin |
A[15:8] <= #1 ACC; |
end |
A[7:0] <= #1 DI_Reg; |
end // case: aIOA |
|
|
aSP : |
begin |
A <= #1 SP; |
end |
|
aBC : |
begin |
if (Mode == 3 && iorq_i == 1'b1 ) |
begin |
// Memory map I/O on GBZ80 |
A[15:8] <= #1 8'hFF; |
A[7:0] <= #1 RegBusC[7:0]; |
end |
else |
begin |
A <= #1 RegBusC; |
end |
end // case: aBC |
|
aDE : |
begin |
A <= #1 RegBusC; |
end |
|
aZI : |
begin |
if (Inc_WZ == 1'b1 ) |
begin |
A <= #1 TmpAddr + 1; |
end |
else |
begin |
A[15:8] <= #1 DI_Reg; |
A[7:0] <= #1 TmpAddr[7:0]; |
end |
end // case: aZI |
|
default : |
begin |
A <= #1 PC; |
end |
endcase // case(Set_Addr_To) |
|
end // else: !if(mcycle[2] && IntCycle == 1'b1 && IStatus == 2'b10 ) |
|
|
Save_ALU_r <= #1 Save_ALU; |
ALU_Op_r <= #1 ALU_Op; |
|
if (I_CPL == 1'b1 ) |
begin |
// CPL |
ACC <= #1 ~ ACC; |
F[Flag_Y] <= #1 ~ ACC[5]; |
F[Flag_H] <= #1 1'b1; |
F[Flag_X] <= #1 ~ ACC[3]; |
F[Flag_N] <= #1 1'b1; |
end |
if (I_CCF == 1'b1 ) |
begin |
// CCF |
F[Flag_C] <= #1 ~ F[Flag_C]; |
F[Flag_Y] <= #1 ACC[5]; |
F[Flag_H] <= #1 F[Flag_C]; |
F[Flag_X] <= #1 ACC[3]; |
F[Flag_N] <= #1 1'b0; |
end |
if (I_SCF == 1'b1 ) |
begin |
// SCF |
F[Flag_C] <= #1 1'b1; |
F[Flag_Y] <= #1 ACC[5]; |
F[Flag_H] <= #1 1'b0; |
F[Flag_X] <= #1 ACC[3]; |
F[Flag_N] <= #1 1'b0; |
end |
end // if (T_Res == 1'b1 ) |
|
|
if (tstate[2] && wait_n == 1'b1 ) |
begin |
if (ISet == 2'b01 && mcycle[6] ) |
begin |
IR <= #1 dinst; |
end |
if (JumpE == 1'b1 ) |
begin |
PC <= #1 PC16; |
end |
else if (Inc_PC == 1'b1 ) |
begin |
//PC <= #1 PC + 1; |
PC <= #1 PC16; |
end |
if (BTR_r == 1'b1 ) |
begin |
//PC <= #1 PC - 2; |
PC <= #1 PC16; |
end |
if (RstP == 1'b1 ) |
begin |
TmpAddr <= #1 { 10'h0, IR[5:3], 3'h0 }; |
//TmpAddr <= #1 (others =>1'b0); |
//TmpAddr[5:3] <= #1 IR[5:3]; |
end |
end |
if (tstate[3] && mcycle[5] ) |
begin |
TmpAddr <= #1 SP16; |
end |
|
if ((tstate[2] && wait_n == 1'b1) || (tstate[4] && mcycle[0]) ) |
begin |
if (IncDec_16[2:0] == 3'b111 ) |
begin |
SP <= #1 SP16; |
end |
end |
|
if (LDSPHL == 1'b1 ) |
begin |
SP <= #1 RegBusC; |
end |
if (ExchangeAF == 1'b1 ) |
begin |
Ap <= #1 ACC; |
ACC <= #1 Ap; |
Fp <= #1 F; |
F <= #1 Fp; |
end |
if (ExchangeRS == 1'b1 ) |
begin |
Alternate <= #1 ~ Alternate; |
end |
end // else: !if(mcycle == 3'b001 && tstate(2) == 1'b0 ) |
|
|
if (tstate[3] ) |
begin |
if (LDZ == 1'b1 ) |
begin |
TmpAddr[7:0] <= #1 DI_Reg; |
end |
if (LDW == 1'b1 ) |
begin |
TmpAddr[15:8] <= #1 DI_Reg; |
end |
|
if (Special_LD[2] == 1'b1 ) |
begin |
case (Special_LD[1:0]) |
2'b00 : |
begin |
ACC <= #1 I; |
F[Flag_P] <= #1 IntE_FF2; |
end |
|
2'b01 : |
begin |
ACC <= #1 R; |
F[Flag_P] <= #1 IntE_FF2; |
end |
|
2'b10 : |
I <= #1 ACC; |
|
default : |
R <= #1 ACC; |
endcase |
end |
end // if (tstate == 3 ) |
|
|
if ((I_DJNZ == 1'b0 && Save_ALU_r == 1'b1) || ALU_Op_r == 4'b1001 ) |
begin |
if (Mode == 3 ) |
begin |
F[6] <= #1 F_Out[6]; |
F[5] <= #1 F_Out[5]; |
F[7] <= #1 F_Out[7]; |
if (PreserveC_r == 1'b0 ) |
begin |
F[4] <= #1 F_Out[4]; |
end |
end |
else |
begin |
F[7:1] <= #1 F_Out[7:1]; |
if (PreserveC_r == 1'b0 ) |
begin |
F[Flag_C] <= #1 F_Out[0]; |
end |
end |
end // if ((I_DJNZ == 1'b0 && Save_ALU_r == 1'b1) || ALU_Op_r == 4'b1001 ) |
|
if (T_Res == 1'b1 && I_INRC == 1'b1 ) |
begin |
F[Flag_H] <= #1 1'b0; |
F[Flag_N] <= #1 1'b0; |
if (DI_Reg[7:0] == 8'b00000000 ) |
begin |
F[Flag_Z] <= #1 1'b1; |
end |
else |
begin |
F[Flag_Z] <= #1 1'b0; |
end |
F[Flag_S] <= #1 DI_Reg[7]; |
F[Flag_P] <= #1 ~ (^DI_Reg[7:0]); |
end // if (T_Res == 1'b1 && I_INRC == 1'b1 ) |
|
|
if (tstate[1] && Auto_Wait_t1 == 1'b0 ) |
begin |
do <= #1 BusB; |
if (I_RLD == 1'b1 ) |
begin |
do[3:0] <= #1 BusA[3:0]; |
do[7:4] <= #1 BusB[3:0]; |
end |
if (I_RRD == 1'b1 ) |
begin |
do[3:0] <= #1 BusB[7:4]; |
do[7:4] <= #1 BusA[3:0]; |
end |
end |
|
if (T_Res == 1'b1 ) |
begin |
Read_To_Reg_r[3:0] <= #1 Set_BusA_To; |
Read_To_Reg_r[4] <= #1 Read_To_Reg; |
if (Read_To_Acc == 1'b1 ) |
begin |
Read_To_Reg_r[3:0] <= #1 4'b0111; |
Read_To_Reg_r[4] <= #1 1'b1; |
end |
end |
|
if (tstate[1] && I_BT == 1'b1 ) |
begin |
F[Flag_X] <= #1 ALU_Q[3]; |
F[Flag_Y] <= #1 ALU_Q[1]; |
F[Flag_H] <= #1 1'b0; |
F[Flag_N] <= #1 1'b0; |
end |
if (I_BC == 1'b1 || I_BT == 1'b1 ) |
begin |
F[Flag_P] <= #1 IncDecZ; |
end |
|
if ((tstate[1] && Save_ALU_r == 1'b0 && Auto_Wait_t1 == 1'b0) || |
(Save_ALU_r == 1'b1 && ALU_Op_r != 4'b0111) ) |
begin |
case (Read_To_Reg_r) |
5'b10111 : |
ACC <= #1 Save_Mux; |
5'b10110 : |
do <= #1 Save_Mux; |
5'b11000 : |
SP[7:0] <= #1 Save_Mux; |
5'b11001 : |
SP[15:8] <= #1 Save_Mux; |
5'b11011 : |
F <= #1 Save_Mux; |
endcase |
end // if ((tstate == 1 && Save_ALU_r == 1'b0 && Auto_Wait_t1 == 1'b0) ||... |
end // if (ClkEn == 1'b1 ) |
end // else: !if(reset_n == 1'b0 ) |
end |
|
|
//------------------------------------------------------------------------- |
// |
// BC('), DE('), HL('), IX && IY |
// |
//------------------------------------------------------------------------- |
always @ (posedge clk) |
begin |
if (ClkEn == 1'b1 ) |
begin |
// Bus A / Write |
RegAddrA_r <= #1 { Alternate, Set_BusA_To[2:1] }; |
if (XY_Ind == 1'b0 && XY_State != 2'b00 && Set_BusA_To[2:1] == 2'b10 ) |
begin |
RegAddrA_r <= #1 { XY_State[1], 2'b11 }; |
end |
|
// Bus B |
RegAddrB_r <= #1 { Alternate, Set_BusB_To[2:1] }; |
if (XY_Ind == 1'b0 && XY_State != 2'b00 && Set_BusB_To[2:1] == 2'b10 ) |
begin |
RegAddrB_r <= #1 { XY_State[1], 2'b11 }; |
end |
|
// Address from register |
RegAddrC <= #1 { Alternate, Set_Addr_To[1:0] }; |
// Jump (HL), LD SP,HL |
if ((JumpXY == 1'b1 || LDSPHL == 1'b1) ) |
begin |
RegAddrC <= #1 { Alternate, 2'b10 }; |
end |
if (((JumpXY == 1'b1 || LDSPHL == 1'b1) && XY_State != 2'b00) || (mcycle[5]) ) |
begin |
RegAddrC <= #1 { XY_State[1], 2'b11 }; |
end |
|
if (I_DJNZ == 1'b1 && Save_ALU_r == 1'b1 && Mode < 2 ) |
begin |
IncDecZ <= #1 F_Out[Flag_Z]; |
end |
if ((tstate[2] || (tstate[3] && mcycle[0])) && IncDec_16[2:0] == 3'b100 ) |
begin |
if (ID16 == 0 ) |
begin |
IncDecZ <= #1 1'b0; |
end |
else |
begin |
IncDecZ <= #1 1'b1; |
end |
end |
|
RegBusA_r <= #1 RegBusA; |
end |
|
end // always @ (posedge clk) |
|
|
always @(/*AUTOSENSE*/Alternate or ExchangeDH or IncDec_16 |
or RegAddrA_r or RegAddrB_r or XY_State or mcycle or tstate) |
begin |
if ((tstate[2] || (tstate[3] && mcycle[0] && IncDec_16[2] == 1'b1)) && XY_State == 2'b00) |
RegAddrA = { Alternate, IncDec_16[1:0] }; |
else if ((tstate[2] || (tstate[3] && mcycle[0] && IncDec_16[2] == 1'b1)) && IncDec_16[1:0] == 2'b10) |
RegAddrA = { XY_State[1], 2'b11 }; |
else /* if (ExchangeDH == 1'b1 && tstate[3]) |
RegAddrA = { Alternate, 2'b10 }; |
else if (ExchangeDH == 1'b1 && tstate[4]) |
RegAddrA = { Alternate, 2'b01 }; |
else */ |
RegAddrA = RegAddrA_r; |
|
/* if (ExchangeDH == 1'b1 && tstate[3]) |
RegAddrB = { Alternate, 2'b01 }; |
else */ |
RegAddrB = RegAddrB_r; |
end // always @ * |
|
|
always @(/*AUTOSENSE*/ALU_Op_r or Auto_Wait_t1 or ExchangeDH |
or IncDec_16 or Read_To_Reg_r or Save_ALU_r or mcycle |
or tstate or wait_n) |
begin |
RegWEH = 1'b0; |
RegWEL = 1'b0; |
if ((tstate[1] && Save_ALU_r == 1'b0 && Auto_Wait_t1 == 1'b0) || |
(Save_ALU_r == 1'b1 && ALU_Op_r != 4'b0111) ) |
begin |
case (Read_To_Reg_r) |
5'b10000 , 5'b10001 , 5'b10010 , 5'b10011 , 5'b10100 , 5'b10101 : |
begin |
RegWEH = ~ Read_To_Reg_r[0]; |
RegWEL = Read_To_Reg_r[0]; |
end |
endcase // case(Read_To_Reg_r) |
|
end // if ((tstate == 1 && Save_ALU_r == 1'b0 && Auto_Wait_t1 == 1'b0) ||... |
|
|
if (ExchangeDH == 1'b1 && (tstate[3] || tstate[4]) ) |
begin |
RegWEH = 1'b1; |
RegWEL = 1'b1; |
end |
|
if (IncDec_16[2] == 1'b1 && ((tstate[2] && wait_n == 1'b1 && mcycle != 3'b001) || (tstate[3] && mcycle[0])) ) |
begin |
case (IncDec_16[1:0]) |
2'b00 , 2'b01 , 2'b10 : |
begin |
RegWEH = 1'b1; |
RegWEL = 1'b1; |
end |
endcase |
end |
end // always @ * |
|
|
always @(/*AUTOSENSE*/ExchangeDH or ID16 or IncDec_16 or RegBusA_r |
or RegBusB or Save_Mux or mcycle or tstate) |
begin |
RegDIH = Save_Mux; |
RegDIL = Save_Mux; |
|
/*if (ExchangeDH == 1'b1 && tstate[3] ) |
begin |
RegDIH = RegBusB[15:8]; |
RegDIL = RegBusB[7:0]; |
end |
else if (ExchangeDH == 1'b1 && tstate[4] ) |
begin |
RegDIH = RegBusA_r[15:8]; |
RegDIL = RegBusA_r[7:0]; |
end |
else */ if (IncDec_16[2] == 1'b1 && ((tstate[2] && mcycle != 3'b001) || (tstate[3] && mcycle[0])) ) |
begin |
RegDIH = ID16[15:8]; |
RegDIL = ID16[7:0]; |
end |
end |
|
tv80_reg i_reg |
( |
.clk (clk), |
.CEN (ClkEn), |
.WEH (RegWEH), |
.WEL (RegWEL), |
.AddrA (RegAddrA), |
.AddrB (RegAddrB), |
.AddrC (RegAddrC), |
.DIH (RegDIH), |
.DIL (RegDIL), |
.DOAH (RegBusA[15:8]), |
.DOAL (RegBusA[7:0]), |
.DOBH (RegBusB[15:8]), |
.DOBL (RegBusB[7:0]), |
.DOCH (RegBusC[15:8]), |
.DOCL (RegBusC[7:0]) |
); |
|
//------------------------------------------------------------------------- |
// |
// Buses |
// |
//------------------------------------------------------------------------- |
|
always @(/*AUTOSENSE*/ACC or DI_Reg or F or PC or RegBusA or RegBusB |
or SP or Set_BusA_To or Set_BusB_To) |
begin |
case (Set_BusB_To) |
4'b0111 : NextBusB = ACC; |
4'b0000 , |
4'b0100 , |
4'b0010 : NextBusB = RegBusB[15:8]; |
4'b0001 , |
4'b0011 , |
4'b0101 : NextBusB = RegBusB[7:0]; |
4'b0110 : NextBusB = DI_Reg; |
4'b1000 : NextBusB = SP[7:0]; |
4'b1001 : NextBusB = SP[15:8]; |
4'b1010 : NextBusB = 8'b00000001; |
4'b1011 : NextBusB = F; |
4'b1100 : NextBusB = PC[7:0]; |
4'b1101 : NextBusB = PC[15:8]; |
4'b1110 : NextBusB = 8'b00000000; |
default : NextBusB = 8'hxx; |
endcase // case(Set_BusB_To) |
|
case (Set_BusA_To) |
4'b0111 : NextBusA = ACC; |
4'b0000 , |
4'b0100 , |
4'b0010 : NextBusA = RegBusA[15:8]; |
4'b0001 , |
4'b0011 , |
4'b0101 : NextBusA = RegBusA[7:0]; |
4'b0110 : NextBusA = DI_Reg; |
4'b1000 : NextBusA = SP[7:0]; |
4'b1001 : NextBusA = SP[15:8]; |
4'b1010 : NextBusA = 8'b00000000; |
default : NextBusA = 8'hxx; |
endcase |
end // always @ (... |
|
always @ (posedge clk) |
begin |
if (ClkEn == 1'b1 ) |
begin |
BusA <= #1 NextBusA; |
BusB <= #1 NextBusB; |
end |
end |
|
//------------------------------------------------------------------------- |
// |
// Generate external control signals |
// |
//------------------------------------------------------------------------- |
always @ (posedge clk) |
begin |
if (reset_n == 1'b0 ) |
begin |
rfsh_n <= #1 1'b1; |
end |
else |
begin |
if (cen == 1'b1 ) |
begin |
if (mcycle[0] && ((tstate[2] && wait_n == 1'b1) || tstate[3]) ) |
begin |
rfsh_n <= #1 1'b0; |
end |
else |
begin |
rfsh_n <= #1 1'b1; |
end |
end |
end |
end |
|
|
always @(/*AUTOSENSE*/BusAck or Halt_FF or I_DJNZ or IntCycle |
or IntE_FF1 or di or iorq_i or mcycle or tstate) |
begin |
mc = mcycle; |
ts = tstate; |
DI_Reg = di; |
halt_n = ~ Halt_FF; |
busak_n = ~ BusAck; |
intcycle_n = ~ IntCycle; |
IntE = IntE_FF1; |
iorq = iorq_i; |
stop = I_DJNZ; |
end |
|
//----------------------------------------------------------------------- |
// |
// Syncronise inputs |
// |
//----------------------------------------------------------------------- |
|
always @ (posedge clk) |
begin : sync_inputs |
|
if (reset_n == 1'b0 ) |
begin |
BusReq_s <= #1 1'b0; |
INT_s <= #1 1'b0; |
NMI_s <= #1 1'b0; |
Oldnmi_n <= #1 1'b0; |
end |
else |
begin |
if (cen == 1'b1 ) |
begin |
BusReq_s <= #1 ~ busrq_n; |
INT_s <= #1 ~ int_n; |
if (NMICycle == 1'b1 ) |
begin |
NMI_s <= #1 1'b0; |
end |
else if (nmi_n == 1'b0 && Oldnmi_n == 1'b1 ) |
begin |
NMI_s <= #1 1'b1; |
end |
Oldnmi_n <= #1 nmi_n; |
end |
end |
end |
|
//----------------------------------------------------------------------- |
// |
// Main state machine |
// |
//----------------------------------------------------------------------- |
|
always @ (posedge clk) |
begin |
if (reset_n == 1'b0 ) |
begin |
mcycle <= #1 7'b0000001; |
tstate <= #1 7'b0000001; |
Pre_XY_F_M <= #1 3'b000; |
Halt_FF <= #1 1'b0; |
BusAck <= #1 1'b0; |
NMICycle <= #1 1'b0; |
IntCycle <= #1 1'b0; |
IntE_FF1 <= #1 1'b0; |
IntE_FF2 <= #1 1'b0; |
No_BTR <= #1 1'b0; |
Auto_Wait_t1 <= #1 1'b0; |
Auto_Wait_t2 <= #1 1'b0; |
m1_n <= #1 1'b1; |
end |
else |
begin |
if (cen == 1'b1 ) |
begin |
if (T_Res == 1'b1 ) |
begin |
Auto_Wait_t1 <= #1 1'b0; |
end |
else |
begin |
Auto_Wait_t1 <= #1 Auto_Wait || iorq_i; |
end |
Auto_Wait_t2 <= #1 Auto_Wait_t1; |
No_BTR <= #1 (I_BT && (~ IR[4] || ~ F[Flag_P])) || |
(I_BC && (~ IR[4] || F[Flag_Z] || ~ F[Flag_P])) || |
(I_BTR && (~ IR[4] || F[Flag_Z])); |
if (tstate[2] ) |
begin |
if (SetEI == 1'b1 ) |
begin |
IntE_FF1 <= #1 1'b1; |
IntE_FF2 <= #1 1'b1; |
end |
if (I_RETN == 1'b1 ) |
begin |
IntE_FF1 <= #1 IntE_FF2; |
end |
end |
if (tstate[3] ) |
begin |
if (SetDI == 1'b1 ) |
begin |
IntE_FF1 <= #1 1'b0; |
IntE_FF2 <= #1 1'b0; |
end |
end |
if (IntCycle == 1'b1 || NMICycle == 1'b1 ) |
begin |
Halt_FF <= #1 1'b0; |
end |
if (mcycle[0] && tstate[2] && wait_n == 1'b1 ) |
begin |
m1_n <= #1 1'b1; |
end |
if (BusReq_s == 1'b1 && BusAck == 1'b1 ) |
begin |
end |
else |
begin |
BusAck <= #1 1'b0; |
if (tstate[2] && wait_n == 1'b0 ) |
begin |
end |
else if (T_Res == 1'b1 ) |
begin |
if (Halt == 1'b1 ) |
begin |
Halt_FF <= #1 1'b1; |
end |
if (BusReq_s == 1'b1 ) |
begin |
BusAck <= #1 1'b1; |
end |
else |
begin |
tstate <= #1 7'b0000010; |
if (NextIs_XY_Fetch == 1'b1 ) |
begin |
mcycle <= #1 7'b0100000; |
Pre_XY_F_M <= #1 mcycle; |
if (IR == 8'b00110110 && Mode == 0 ) |
begin |
Pre_XY_F_M <= #1 3'b010; |
end |
end |
else if ((mcycle[6]) || (mcycle[5] && Mode == 1 && ISet != 2'b01) ) |
begin |
mcycle <= #1 number_to_bitvec(Pre_XY_F_M + 1); |
end |
else if ((last_mcycle) || |
No_BTR == 1'b1 || |
(mcycle[1] && I_DJNZ == 1'b1 && IncDecZ == 1'b1) ) |
begin |
m1_n <= #1 1'b0; |
mcycle <= #1 7'b0000001; |
IntCycle <= #1 1'b0; |
NMICycle <= #1 1'b0; |
if (NMI_s == 1'b1 && Prefix == 2'b00 ) |
begin |
NMICycle <= #1 1'b1; |
IntE_FF1 <= #1 1'b0; |
end |
else if ((IntE_FF1 == 1'b1 && INT_s == 1'b1) && Prefix == 2'b00 && SetEI == 1'b0 ) |
begin |
IntCycle <= #1 1'b1; |
IntE_FF1 <= #1 1'b0; |
IntE_FF2 <= #1 1'b0; |
end |
end |
else |
begin |
mcycle <= #1 { mcycle[5:0], mcycle[6] }; |
end |
end |
end |
else |
begin // verilog has no "nor" operator |
if ( ~(Auto_Wait == 1'b1 && Auto_Wait_t2 == 1'b0) && |
~(IOWait == 1 && iorq_i == 1'b1 && Auto_Wait_t1 == 1'b0) ) |
begin |
tstate <= #1 { tstate[5:0], tstate[6] }; |
end |
end |
end |
if (tstate[0]) |
begin |
m1_n <= #1 1'b0; |
end |
end |
end |
end |
|
always @(/*AUTOSENSE*/BTR_r or DI_Reg or IncDec_16 or JumpE or PC |
or RegBusA or RegBusC or SP or tstate) |
begin |
if (JumpE == 1'b1 ) |
begin |
PC16_B = { {8{DI_Reg[7]}}, DI_Reg }; |
end |
else if (BTR_r == 1'b1 ) |
begin |
PC16_B = -2; |
end |
else |
begin |
PC16_B = 1; |
end |
|
if (tstate[3]) |
begin |
SP16_A = RegBusC; |
SP16_B = { {8{DI_Reg[7]}}, DI_Reg }; |
end |
else |
begin |
// suspect that ID16 and SP16 could be shared |
SP16_A = SP; |
|
if (IncDec_16[3] == 1'b1) |
SP16_B = -1; |
else |
SP16_B = 1; |
end |
|
if (IncDec_16[3]) |
ID16_B = -1; |
else |
ID16_B = 1; |
|
ID16 = RegBusA + ID16_B; |
PC16 = PC + PC16_B; |
SP16 = SP16_A + SP16_B; |
end // always @ * |
|
|
always @(/*AUTOSENSE*/IntCycle or NMICycle or mcycle) |
begin |
Auto_Wait = 1'b0; |
if (IntCycle == 1'b1 || NMICycle == 1'b1 ) |
begin |
if (mcycle[0] ) |
begin |
Auto_Wait = 1'b1; |
end |
end |
end // always @ * |
|
// synopsys dc_script_begin |
// set_attribute current_design "revision" "$Id: tv80_core.v,v 1.4.4.1 2004-12-16 00:46:19 ghutchis Exp $" -type string -quiet |
// synopsys dc_script_end |
endmodule // T80 |
|
/core/tv80_mcode_cb.v
0,0 → 1,442
// |
// TV80 8-Bit Microprocessor Core |
// Based on the VHDL T80 core by Daniel Wallner (jesus@opencores.org) |
// |
// Copyright (c) 2004 Guy Hutchison (ghutchis@opencores.org) |
// |
// Permission is hereby granted, free of charge, to any person obtaining a |
// copy of this software and associated documentation files (the "Software"), |
// to deal in the Software without restriction, including without limitation |
// the rights to use, copy, modify, merge, publish, distribute, sublicense, |
// and/or sell copies of the Software, and to permit persons to whom the |
// Software is furnished to do so, subject to the following conditions: |
// |
// The above copyright notice and this permission notice shall be included |
// in all copies or substantial portions of the Software. |
// |
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, |
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. |
// IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY |
// CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, |
// TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE |
// SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. |
|
module tv80_mcode_cb |
(/*AUTOARG*/ |
// Outputs |
output_vector, |
// Inputs |
IR, MCycle |
); |
|
parameter Mode = 0; |
parameter Flag_C = 0; |
parameter Flag_N = 1; |
parameter Flag_P = 2; |
parameter Flag_X = 3; |
parameter Flag_H = 4; |
parameter Flag_Y = 5; |
parameter Flag_Z = 6; |
parameter Flag_S = 7; |
|
output [67:0] output_vector; |
|
input [7:0] IR; |
input [6:0] MCycle ; |
|
// regs |
reg [2:0] MCycles ; |
reg [2:0] TStates ; |
reg [1:0] Prefix ; // None,BC,ED,DD/FD |
reg Inc_PC ; |
reg Inc_WZ ; |
reg [3:0] IncDec_16 ; // BC,DE,HL,SP 0 is inc |
reg Read_To_Reg ; |
reg Read_To_Acc ; |
reg [3:0] Set_BusA_To ; // B,C,D,E,H,L,DI/DB,A,SP(L),SP(M),0,F |
reg [3:0] Set_BusB_To ; // B,C,D,E,H,L,DI,A,SP(L),SP(M),1,F,PC(L),PC(M),0 |
reg [3:0] ALU_Op ; |
reg Save_ALU ; |
reg PreserveC ; |
reg Arith16 ; |
reg [2:0] Set_Addr_To ; // aNone,aXY,aIOA,aSP,aBC,aDE,aZI |
reg IORQ ; |
reg Jump ; |
reg JumpE ; |
reg JumpXY ; |
reg Call ; |
reg RstP ; |
reg LDZ ; |
reg LDW ; |
reg LDSPHL ; |
reg [2:0] Special_LD ; // A,I;A,R;I,A;R,A;None |
reg ExchangeDH ; |
reg ExchangeRp ; |
reg ExchangeAF ; |
reg ExchangeRS ; |
reg I_DJNZ ; |
reg I_CPL ; |
reg I_CCF ; |
reg I_SCF ; |
reg I_RETN ; |
reg I_BT ; |
reg I_BC ; |
reg I_BTR ; |
reg I_RLD ; |
reg I_RRD ; |
reg I_INRC ; |
reg SetDI ; |
reg SetEI ; |
reg [1:0] IMode ; |
reg Halt ; |
reg NoRead ; |
reg Write ; |
|
parameter aNone = 3'b111; |
parameter aBC = 3'b000; |
parameter aDE = 3'b001; |
parameter aXY = 3'b010; |
parameter aIOA = 3'b100; |
parameter aSP = 3'b101; |
parameter aZI = 3'b110; |
// constant aNone : std_logic_vector[2:0] = 3'b000; |
// constant aXY : std_logic_vector[2:0] = 3'b001; |
// constant aIOA : std_logic_vector[2:0] = 3'b010; |
// constant aSP : std_logic_vector[2:0] = 3'b011; |
// constant aBC : std_logic_vector[2:0] = 3'b100; |
// constant aDE : std_logic_vector[2:0] = 3'b101; |
// constant aZI : std_logic_vector[2:0] = 3'b110; |
|
function is_cc_true; |
input [7:0] F; |
input [2:0] cc; |
begin |
if (Mode == 3 ) |
begin |
case (cc) |
3'b000 : is_cc_true = F[7] == 1'b0; // NZ |
3'b001 : is_cc_true = F[7] == 1'b1; // Z |
3'b010 : is_cc_true = F[4] == 1'b0; // NC |
3'b011 : is_cc_true = F[4] == 1'b1; // C |
3'b100 : is_cc_true = 0; |
3'b101 : is_cc_true = 0; |
3'b110 : is_cc_true = 0; |
3'b111 : is_cc_true = 0; |
endcase |
end |
else |
begin |
case (cc) |
3'b000 : is_cc_true = F[6] == 1'b0; // NZ |
3'b001 : is_cc_true = F[6] == 1'b1; // Z |
3'b010 : is_cc_true = F[0] == 1'b0; // NC |
3'b011 : is_cc_true = F[0] == 1'b1; // C |
3'b100 : is_cc_true = F[2] == 1'b0; // PO |
3'b101 : is_cc_true = F[2] == 1'b1; // PE |
3'b110 : is_cc_true = F[7] == 1'b0; // P |
3'b111 : is_cc_true = F[7] == 1'b1; // M |
endcase |
end |
end |
endfunction // is_cc_true |
|
|
reg [2:0] DDD; |
reg [2:0] SSS; |
reg [1:0] DPAIR; |
reg [7:0] IRB; |
|
always @ (/*AUTOSENSE*/IR or MCycle) |
begin |
DDD = IR[5:3]; |
SSS = IR[2:0]; |
DPAIR = IR[5:4]; |
IRB = IR; |
|
MCycles = 3'b001; |
if (MCycle[0] ) |
begin |
TStates = 3'b100; |
end |
else |
begin |
TStates = 3'b011; |
end |
Prefix = 2'b00; |
Inc_PC = 1'b0; |
Inc_WZ = 1'b0; |
IncDec_16 = 4'b0000; |
Read_To_Acc = 1'b0; |
Read_To_Reg = 1'b0; |
Set_BusB_To = 4'b0000; |
Set_BusA_To = 4'b0000; |
ALU_Op = { 1'b0, IR[5:3] }; |
Save_ALU = 1'b0; |
PreserveC = 1'b0; |
Arith16 = 1'b0; |
IORQ = 1'b0; |
Set_Addr_To = aNone; |
Jump = 1'b0; |
JumpE = 1'b0; |
JumpXY = 1'b0; |
Call = 1'b0; |
RstP = 1'b0; |
LDZ = 1'b0; |
LDW = 1'b0; |
LDSPHL = 1'b0; |
Special_LD = 3'b000; |
ExchangeDH = 1'b0; |
ExchangeRp = 1'b0; |
ExchangeAF = 1'b0; |
ExchangeRS = 1'b0; |
I_DJNZ = 1'b0; |
I_CPL = 1'b0; |
I_CCF = 1'b0; |
I_SCF = 1'b0; |
I_RETN = 1'b0; |
I_BT = 1'b0; |
I_BC = 1'b0; |
I_BTR = 1'b0; |
I_RLD = 1'b0; |
I_RRD = 1'b0; |
I_INRC = 1'b0; |
SetDI = 1'b0; |
SetEI = 1'b0; |
IMode = 2'b11; |
Halt = 1'b0; |
NoRead = 1'b0; |
Write = 1'b0; |
|
|
//---------------------------------------------------------------------------- |
// |
// CB prefixed instructions |
// |
//---------------------------------------------------------------------------- |
|
Set_BusA_To[2:0] = IR[2:0]; |
Set_BusB_To[2:0] = IR[2:0]; |
|
case (IRB) |
8'b00000000,8'b00000001,8'b00000010,8'b00000011,8'b00000100,8'b00000101,8'b00000111, |
8'b00010000,8'b00010001,8'b00010010,8'b00010011,8'b00010100,8'b00010101,8'b00010111, |
8'b00001000,8'b00001001,8'b00001010,8'b00001011,8'b00001100,8'b00001101,8'b00001111, |
8'b00011000,8'b00011001,8'b00011010,8'b00011011,8'b00011100,8'b00011101,8'b00011111, |
8'b00100000,8'b00100001,8'b00100010,8'b00100011,8'b00100100,8'b00100101,8'b00100111, |
8'b00101000,8'b00101001,8'b00101010,8'b00101011,8'b00101100,8'b00101101,8'b00101111, |
8'b00110000,8'b00110001,8'b00110010,8'b00110011,8'b00110100,8'b00110101,8'b00110111, |
8'b00111000,8'b00111001,8'b00111010,8'b00111011,8'b00111100,8'b00111101,8'b00111111 : |
begin |
// RLC r |
// RL r |
// RRC r |
// RR r |
// SLA r |
// SRA r |
// SRL r |
// SLL r (Undocumented) / SWAP r |
if (MCycle[0] ) begin |
ALU_Op = 4'b1000; |
Read_To_Reg = 1'b1; |
Save_ALU = 1'b1; |
end |
end // case: 8'b00000000,8'b00000001,8'b00000010,8'b00000011,8'b00000100,8'b00000101,8'b00000111,... |
|
8'b00000110,8'b00010110,8'b00001110,8'b00011110,8'b00101110,8'b00111110,8'b00100110,8'b00110110 : |
begin |
// RLC (HL) |
// RL (HL) |
// RRC (HL) |
// RR (HL) |
// SRA (HL) |
// SRL (HL) |
// SLA (HL) |
// SLL (HL) (Undocumented) / SWAP (HL) |
MCycles = 3'b011; |
case (1'b1) // MCycle |
MCycle[0], MCycle[6] : |
Set_Addr_To = aXY; |
MCycle[1] : |
begin |
ALU_Op = 4'b1000; |
Read_To_Reg = 1'b1; |
Save_ALU = 1'b1; |
Set_Addr_To = aXY; |
TStates = 3'b100; |
end |
|
MCycle[2] : |
Write = 1'b1; |
default :; |
endcase // case(MCycle) |
end // case: 8'b00000110,8'b00010110,8'b00001110,8'b00011110,8'b00101110,8'b00111110,8'b00100110,8'b00110110 |
|
8'b01000000,8'b01000001,8'b01000010,8'b01000011,8'b01000100,8'b01000101,8'b01000111, |
8'b01001000,8'b01001001,8'b01001010,8'b01001011,8'b01001100,8'b01001101,8'b01001111, |
8'b01010000,8'b01010001,8'b01010010,8'b01010011,8'b01010100,8'b01010101,8'b01010111, |
8'b01011000,8'b01011001,8'b01011010,8'b01011011,8'b01011100,8'b01011101,8'b01011111, |
8'b01100000,8'b01100001,8'b01100010,8'b01100011,8'b01100100,8'b01100101,8'b01100111, |
8'b01101000,8'b01101001,8'b01101010,8'b01101011,8'b01101100,8'b01101101,8'b01101111, |
8'b01110000,8'b01110001,8'b01110010,8'b01110011,8'b01110100,8'b01110101,8'b01110111, |
8'b01111000,8'b01111001,8'b01111010,8'b01111011,8'b01111100,8'b01111101,8'b01111111 : |
begin |
// BIT b,r |
if (MCycle[0] ) |
begin |
Set_BusB_To[2:0] = IR[2:0]; |
ALU_Op = 4'b1001; |
end |
end // case: 8'b01000000,8'b01000001,8'b01000010,8'b01000011,8'b01000100,8'b01000101,8'b01000111,... |
|
8'b01000110,8'b01001110,8'b01010110,8'b01011110,8'b01100110,8'b01101110,8'b01110110,8'b01111110 : |
begin |
// BIT b,(HL) |
MCycles = 3'b010; |
case (1'b1) // MCycle |
MCycle[0], MCycle[6] : |
Set_Addr_To = aXY; |
MCycle[1] : |
begin |
ALU_Op = 4'b1001; |
TStates = 3'b100; |
end |
|
default :; |
endcase // case(MCycle) |
end // case: 8'b01000110,8'b01001110,8'b01010110,8'b01011110,8'b01100110,8'b01101110,8'b01110110,8'b01111110 |
|
8'b11000000,8'b11000001,8'b11000010,8'b11000011,8'b11000100,8'b11000101,8'b11000111, |
8'b11001000,8'b11001001,8'b11001010,8'b11001011,8'b11001100,8'b11001101,8'b11001111, |
8'b11010000,8'b11010001,8'b11010010,8'b11010011,8'b11010100,8'b11010101,8'b11010111, |
8'b11011000,8'b11011001,8'b11011010,8'b11011011,8'b11011100,8'b11011101,8'b11011111, |
8'b11100000,8'b11100001,8'b11100010,8'b11100011,8'b11100100,8'b11100101,8'b11100111, |
8'b11101000,8'b11101001,8'b11101010,8'b11101011,8'b11101100,8'b11101101,8'b11101111, |
8'b11110000,8'b11110001,8'b11110010,8'b11110011,8'b11110100,8'b11110101,8'b11110111, |
8'b11111000,8'b11111001,8'b11111010,8'b11111011,8'b11111100,8'b11111101,8'b11111111 : |
begin |
// SET b,r |
if (MCycle[0] ) |
begin |
ALU_Op = 4'b1010; |
Read_To_Reg = 1'b1; |
Save_ALU = 1'b1; |
end |
end // case: 8'b11000000,8'b11000001,8'b11000010,8'b11000011,8'b11000100,8'b11000101,8'b11000111,... |
|
8'b11000110,8'b11001110,8'b11010110,8'b11011110,8'b11100110,8'b11101110,8'b11110110,8'b11111110 : |
begin |
// SET b,(HL) |
MCycles = 3'b011; |
case (1'b1) // MCycle |
MCycle[0], MCycle[6] : |
Set_Addr_To = aXY; |
MCycle[1] : |
begin |
ALU_Op = 4'b1010; |
Read_To_Reg = 1'b1; |
Save_ALU = 1'b1; |
Set_Addr_To = aXY; |
TStates = 3'b100; |
end |
MCycle[2] : |
Write = 1'b1; |
default :; |
endcase // case(MCycle) |
end // case: 8'b11000110,8'b11001110,8'b11010110,8'b11011110,8'b11100110,8'b11101110,8'b11110110,8'b11111110 |
|
8'b10000000,8'b10000001,8'b10000010,8'b10000011,8'b10000100,8'b10000101,8'b10000111, |
8'b10001000,8'b10001001,8'b10001010,8'b10001011,8'b10001100,8'b10001101,8'b10001111, |
8'b10010000,8'b10010001,8'b10010010,8'b10010011,8'b10010100,8'b10010101,8'b10010111, |
8'b10011000,8'b10011001,8'b10011010,8'b10011011,8'b10011100,8'b10011101,8'b10011111, |
8'b10100000,8'b10100001,8'b10100010,8'b10100011,8'b10100100,8'b10100101,8'b10100111, |
8'b10101000,8'b10101001,8'b10101010,8'b10101011,8'b10101100,8'b10101101,8'b10101111, |
8'b10110000,8'b10110001,8'b10110010,8'b10110011,8'b10110100,8'b10110101,8'b10110111, |
8'b10111000,8'b10111001,8'b10111010,8'b10111011,8'b10111100,8'b10111101,8'b10111111 : |
begin |
// RES b,r |
if (MCycle[0] ) |
begin |
ALU_Op = 4'b1011; |
Read_To_Reg = 1'b1; |
Save_ALU = 1'b1; |
end |
end // case: 8'b10000000,8'b10000001,8'b10000010,8'b10000011,8'b10000100,8'b10000101,8'b10000111,... |
|
8'b10000110,8'b10001110,8'b10010110,8'b10011110,8'b10100110,8'b10101110,8'b10110110,8'b10111110 : |
begin |
// RES b,(HL) |
MCycles = 3'b011; |
case (1'b1) // MCycle |
MCycle[0], MCycle[6] : |
Set_Addr_To = aXY; |
MCycle[1] : |
begin |
ALU_Op = 4'b1011; |
Read_To_Reg = 1'b1; |
Save_ALU = 1'b1; |
Set_Addr_To = aXY; |
TStates = 3'b100; |
end |
|
MCycle[2] : |
Write = 1'b1; |
default :; |
endcase // case(MCycle) |
end // case: 8'b10000110,8'b10001110,8'b10010110,8'b10011110,8'b10100110,8'b10101110,8'b10110110,8'b10111110 |
|
endcase // case(IRB) |
|
end // always @ (IR, ISet, MCycle, F, NMICycle, IntCycle) |
|
assign output_vector = { MCycles, |
TStates, |
Prefix, |
Inc_PC, |
Inc_WZ, |
IncDec_16, |
Read_To_Reg, |
Read_To_Acc, |
Set_BusA_To, |
Set_BusB_To, |
ALU_Op, |
Save_ALU, |
PreserveC, |
Arith16, |
Set_Addr_To, |
IORQ, |
Jump, |
JumpE, |
JumpXY, |
Call, |
RstP, |
LDZ, |
LDW, |
LDSPHL, |
Special_LD, |
ExchangeDH, |
ExchangeRp, |
ExchangeAF, |
ExchangeRS, |
I_DJNZ, |
I_CPL, |
I_CCF, |
I_SCF, |
I_RETN, |
I_BT, |
I_BC, |
I_BTR, |
I_RLD, |
I_RRD, |
I_INRC, |
SetDI, |
SetEI, |
IMode, |
Halt, |
NoRead, |
Write }; |
|
// synopsys dc_script_begin |
// set_attribute current_design "revision" "$Id: tv80_mcode_cb.v,v 1.1.2.1 2004-11-30 21:58:10 ghutchis Exp $" -type string -quiet |
// synopsys dc_script_end |
endmodule // T80_MCode |
/core/tv80_reg.v
0,0 → 1,75
// |
// TV80 8-Bit Microprocessor Core |
// Based on the VHDL T80 core by Daniel Wallner (jesus@opencores.org) |
// |
// Copyright (c) 2004 Guy Hutchison (ghutchis@opencores.org) |
// |
// Permission is hereby granted, free of charge, to any person obtaining a |
// copy of this software and associated documentation files (the "Software"), |
// to deal in the Software without restriction, including without limitation |
// the rights to use, copy, modify, merge, publish, distribute, sublicense, |
// and/or sell copies of the Software, and to permit persons to whom the |
// Software is furnished to do so, subject to the following conditions: |
// |
// The above copyright notice and this permission notice shall be included |
// in all copies or substantial portions of the Software. |
// |
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, |
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. |
// IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY |
// CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, |
// TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE |
// SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. |
|
module tv80_reg (/*AUTOARG*/ |
// Outputs |
DOBH, DOAL, DOCL, DOBL, DOCH, DOAH, |
// Inputs |
AddrC, AddrA, AddrB, DIH, DIL, clk, CEN, WEH, WEL |
); |
input [2:0] AddrC; |
output [7:0] DOBH; |
input [2:0] AddrA; |
input [2:0] AddrB; |
input [7:0] DIH; |
output [7:0] DOAL; |
output [7:0] DOCL; |
input [7:0] DIL; |
output [7:0] DOBL; |
output [7:0] DOCH; |
output [7:0] DOAH; |
input clk, CEN, WEH, WEL; |
|
reg [7:0] RegsH [0:7]; |
reg [7:0] RegsL [0:7]; |
|
always @(posedge clk) |
begin |
if (CEN) |
begin |
if (WEH) RegsH[AddrA] <= DIH; |
if (WEL) RegsL[AddrA] <= DIL; |
end |
end |
|
assign DOAH = RegsH[AddrA]; |
assign DOAL = RegsL[AddrA]; |
assign DOBH = RegsH[AddrB]; |
assign DOBL = RegsL[AddrB]; |
assign DOCH = RegsH[AddrC]; |
assign DOCL = RegsL[AddrC]; |
|
// break out ram bits for waveform debug |
wire [7:0] H = RegsH[2]; |
wire [7:0] L = RegsL[2]; |
wire [7:0] B = RegsH[0]; |
wire [7:0] C = RegsL[0]; |
wire [7:0] D = RegsH[1]; |
wire [7:0] E = RegsL[1]; |
|
// synopsys dc_script_begin |
// set_attribute current_design "revision" "$Id: tv80_reg.v,v 1.1.8.1 2004-11-30 21:58:10 ghutchis Exp $" -type string -quiet |
// synopsys dc_script_end |
endmodule |
|
/core/tv80_mcode_ed.v
0,0 → 1,820
// |
// TV80 8-Bit Microprocessor Core |
// Based on the VHDL T80 core by Daniel Wallner (jesus@opencores.org) |
// |
// Copyright (c) 2004 Guy Hutchison (ghutchis@opencores.org) |
// |
// Permission is hereby granted, free of charge, to any person obtaining a |
// copy of this software and associated documentation files (the "Software"), |
// to deal in the Software without restriction, including without limitation |
// the rights to use, copy, modify, merge, publish, distribute, sublicense, |
// and/or sell copies of the Software, and to permit persons to whom the |
// Software is furnished to do so, subject to the following conditions: |
// |
// The above copyright notice and this permission notice shall be included |
// in all copies or substantial portions of the Software. |
// |
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, |
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. |
// IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY |
// CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, |
// TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE |
// SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. |
|
module tv80_mcode_ed |
(/*AUTOARG*/ |
// Outputs |
output_vector, |
// Inputs |
IR, MCycle |
); |
|
parameter Mode = 0; |
parameter Flag_C = 0; |
parameter Flag_N = 1; |
parameter Flag_P = 2; |
parameter Flag_X = 3; |
parameter Flag_H = 4; |
parameter Flag_Y = 5; |
parameter Flag_Z = 6; |
parameter Flag_S = 7; |
|
output [67:0] output_vector; |
|
input [7:0] IR; |
input [6:0] MCycle ; |
|
// regs |
reg [2:0] MCycles ; |
reg [2:0] TStates ; |
reg [1:0] Prefix ; // None,BC,ED,DD/FD |
reg Inc_PC ; |
reg Inc_WZ ; |
reg [3:0] IncDec_16 ; // BC,DE,HL,SP 0 is inc |
reg Read_To_Reg ; |
reg Read_To_Acc ; |
reg [3:0] Set_BusA_To ; // B,C,D,E,H,L,DI/DB,A,SP(L),SP(M),0,F |
reg [3:0] Set_BusB_To ; // B,C,D,E,H,L,DI,A,SP(L),SP(M),1,F,PC(L),PC(M),0 |
reg [3:0] ALU_Op ; |
reg Save_ALU ; |
reg PreserveC ; |
reg Arith16 ; |
reg [2:0] Set_Addr_To ; // aNone,aXY,aIOA,aSP,aBC,aDE,aZI |
reg IORQ ; |
reg Jump ; |
reg JumpE ; |
reg JumpXY ; |
reg Call ; |
reg RstP ; |
reg LDZ ; |
reg LDW ; |
reg LDSPHL ; |
reg [2:0] Special_LD ; // A,I;A,R;I,A;R,A;None |
reg ExchangeDH ; |
reg ExchangeRp ; |
reg ExchangeAF ; |
reg ExchangeRS ; |
reg I_DJNZ ; |
reg I_CPL ; |
reg I_CCF ; |
reg I_SCF ; |
reg I_RETN ; |
reg I_BT ; |
reg I_BC ; |
reg I_BTR ; |
reg I_RLD ; |
reg I_RRD ; |
reg I_INRC ; |
reg SetDI ; |
reg SetEI ; |
reg [1:0] IMode ; |
reg Halt ; |
reg NoRead ; |
reg Write ; |
|
parameter aNone = 3'b111; |
parameter aBC = 3'b000; |
parameter aDE = 3'b001; |
parameter aXY = 3'b010; |
parameter aIOA = 3'b100; |
parameter aSP = 3'b101; |
parameter aZI = 3'b110; |
|
|
reg [2:0] DDD; |
reg [2:0] SSS; |
reg [1:0] DPAIR; |
reg [7:0] IRB; |
|
always @ (/*AUTOSENSE*/IR or MCycle) |
begin |
DDD = IR[5:3]; |
SSS = IR[2:0]; |
DPAIR = IR[5:4]; |
IRB = IR; |
|
MCycles = 3'b001; |
if (MCycle[0] ) |
begin |
TStates = 3'b100; |
end |
else |
begin |
TStates = 3'b011; |
end |
Prefix = 2'b00; |
Inc_PC = 1'b0; |
Inc_WZ = 1'b0; |
IncDec_16 = 4'b0000; |
Read_To_Acc = 1'b0; |
Read_To_Reg = 1'b0; |
Set_BusB_To = 4'b0000; |
Set_BusA_To = 4'b0000; |
ALU_Op = { 1'b0, IR[5:3] }; |
Save_ALU = 1'b0; |
PreserveC = 1'b0; |
Arith16 = 1'b0; |
IORQ = 1'b0; |
Set_Addr_To = aNone; |
Jump = 1'b0; |
JumpE = 1'b0; |
JumpXY = 1'b0; |
Call = 1'b0; |
RstP = 1'b0; |
LDZ = 1'b0; |
LDW = 1'b0; |
LDSPHL = 1'b0; |
Special_LD = 3'b000; |
ExchangeDH = 1'b0; |
ExchangeRp = 1'b0; |
ExchangeAF = 1'b0; |
ExchangeRS = 1'b0; |
I_DJNZ = 1'b0; |
I_CPL = 1'b0; |
I_CCF = 1'b0; |
I_SCF = 1'b0; |
I_RETN = 1'b0; |
I_BT = 1'b0; |
I_BC = 1'b0; |
I_BTR = 1'b0; |
I_RLD = 1'b0; |
I_RRD = 1'b0; |
I_INRC = 1'b0; |
SetDI = 1'b0; |
SetEI = 1'b0; |
IMode = 2'b11; |
Halt = 1'b0; |
NoRead = 1'b0; |
Write = 1'b0; |
|
//---------------------------------------------------------------------------- |
// |
// ED prefixed instructions |
// |
//---------------------------------------------------------------------------- |
|
casex (IRB) |
// 8 BIT LOAD GROUP |
8'b01010111 : |
begin |
// LD A,I |
Special_LD = 3'b100; |
TStates = 3'b101; |
end |
|
8'b01011111 : |
begin |
// LD A,R |
Special_LD = 3'b101; |
TStates = 3'b101; |
end |
|
8'b01000111 : |
begin |
// LD I,A |
Special_LD = 3'b110; |
TStates = 3'b101; |
end |
|
8'b01001111 : |
begin |
// LD R,A |
Special_LD = 3'b111; |
TStates = 3'b101; |
end |
|
// 16 BIT LOAD GROUP |
8'b01xx1011 : |
begin |
// LD dd,(nn) |
MCycles = 3'b101; |
case (1'b1) // MCycle |
MCycle[1] : |
begin |
Inc_PC = 1'b1; |
LDZ = 1'b1; |
end |
|
MCycle[2] : |
begin |
Set_Addr_To = aZI; |
Inc_PC = 1'b1; |
LDW = 1'b1; |
end |
|
MCycle[3] : |
begin |
Read_To_Reg = 1'b1; |
if (IR[5:4] == 2'b11 ) |
begin |
Set_BusA_To = 4'b1000; |
end |
else |
begin |
Set_BusA_To[2:1] = IR[5:4]; |
Set_BusA_To[0] = 1'b1; |
end |
Inc_WZ = 1'b1; |
Set_Addr_To = aZI; |
end // case: 4 |
|
MCycle[4] : |
begin |
Read_To_Reg = 1'b1; |
if (IR[5:4] == 2'b11 ) |
begin |
Set_BusA_To = 4'b1001; |
end |
else |
begin |
Set_BusA_To[2:1] = IR[5:4]; |
Set_BusA_To[0] = 1'b0; |
end |
end // case: 5 |
|
default :; |
endcase // case(MCycle) |
end // case: 8'b01001011,8'b01011011,8'b01101011,8'b01111011 |
|
|
8'b01xx0011 : |
begin |
// LD (nn),dd |
MCycles = 3'b101; |
case (1'b1) // MCycle |
MCycle[1] : |
begin |
Inc_PC = 1'b1; |
LDZ = 1'b1; |
end |
|
MCycle[2] : |
begin |
Set_Addr_To = aZI; |
Inc_PC = 1'b1; |
LDW = 1'b1; |
if (IR[5:4] == 2'b11 ) |
begin |
Set_BusB_To = 4'b1000; |
end |
else |
begin |
Set_BusB_To[2:1] = IR[5:4]; |
Set_BusB_To[0] = 1'b1; |
Set_BusB_To[3] = 1'b0; |
end |
end // case: 3 |
|
MCycle[3] : |
begin |
Inc_WZ = 1'b1; |
Set_Addr_To = aZI; |
Write = 1'b1; |
if (IR[5:4] == 2'b11 ) |
begin |
Set_BusB_To = 4'b1001; |
end |
else |
begin |
Set_BusB_To[2:1] = IR[5:4]; |
Set_BusB_To[0] = 1'b0; |
Set_BusB_To[3] = 1'b0; |
end |
end // case: 4 |
|
MCycle[4] : |
begin |
Write = 1'b1; |
end |
|
default :; |
endcase // case(MCycle) |
end // case: 8'b01000011,8'b01010011,8'b01100011,8'b01110011 |
|
8'b101xx000 : |
begin |
// LDI, LDD, LDIR, LDDR |
MCycles = 3'b100; |
case (1'b1) // MCycle |
MCycle[0] : |
begin |
Set_Addr_To = aXY; |
IncDec_16 = 4'b1100; // BC |
end |
|
MCycle[1] : |
begin |
Set_BusB_To = 4'b0110; |
Set_BusA_To[2:0] = 3'b111; |
ALU_Op = 4'b0000; |
Set_Addr_To = aDE; |
if (IR[3] == 1'b0 ) |
begin |
IncDec_16 = 4'b0110; // IX |
end |
else |
begin |
IncDec_16 = 4'b1110; |
end |
end // case: 2 |
|
MCycle[2] : |
begin |
I_BT = 1'b1; |
TStates = 3'b101; |
Write = 1'b1; |
if (IR[3] == 1'b0 ) |
begin |
IncDec_16 = 4'b0101; // DE |
end |
else |
begin |
IncDec_16 = 4'b1101; |
end |
end // case: 3 |
|
MCycle[3] : |
begin |
NoRead = 1'b1; |
TStates = 3'b101; |
end |
|
default :; |
endcase // case(MCycle) |
end // case: 8'b10100000 , 8'b10101000 , 8'b10110000 , 8'b10111000 |
|
8'b101xx001 : |
begin |
// CPI, CPD, CPIR, CPDR |
MCycles = 3'b100; |
case (1'b1) // MCycle |
MCycle[0] : |
begin |
Set_Addr_To = aXY; |
IncDec_16 = 4'b1100; // BC |
end |
|
MCycle[1] : |
begin |
Set_BusB_To = 4'b0110; |
Set_BusA_To[2:0] = 3'b111; |
ALU_Op = 4'b0111; |
Save_ALU = 1'b1; |
PreserveC = 1'b1; |
if (IR[3] == 1'b0 ) |
begin |
IncDec_16 = 4'b0110; |
end |
else |
begin |
IncDec_16 = 4'b1110; |
end |
end // case: 2 |
|
MCycle[2] : |
begin |
NoRead = 1'b1; |
I_BC = 1'b1; |
TStates = 3'b101; |
end |
|
MCycle[3] : |
begin |
NoRead = 1'b1; |
TStates = 3'b101; |
end |
|
default :; |
endcase // case(MCycle) |
end // case: 8'b10100001 , 8'b10101001 , 8'b10110001 , 8'b10111001 |
|
8'b01xxx100 : |
begin |
// NEG |
ALU_Op = 4'b0010; |
Set_BusB_To = 4'b0111; |
Set_BusA_To = 4'b1010; |
Read_To_Acc = 1'b1; |
Save_ALU = 1'b1; |
end |
|
8'b01000110,8'b01001110,8'b01100110,8'b01101110 : |
begin |
// IM 0 |
IMode = 2'b00; |
end |
|
8'b01010110,8'b01110110 : |
// IM 1 |
IMode = 2'b01; |
|
8'b01011110,8'b01110111 : |
// IM 2 |
IMode = 2'b10; |
|
// 16 bit arithmetic |
8'b01001010,8'b01011010,8'b01101010,8'b01111010 : |
begin |
// ADC HL,ss |
MCycles = 3'b011; |
case (1'b1) // MCycle |
MCycle[1] : |
begin |
NoRead = 1'b1; |
ALU_Op = 4'b0001; |
Read_To_Reg = 1'b1; |
Save_ALU = 1'b1; |
Set_BusA_To[2:0] = 3'b101; |
case (IR[5:4]) |
0,1,2 : |
begin |
Set_BusB_To[2:1] = IR[5:4]; |
Set_BusB_To[0] = 1'b1; |
end |
default : |
Set_BusB_To = 4'b1000; |
endcase |
TStates = 3'b100; |
end // case: 2 |
|
MCycle[2] : |
begin |
NoRead = 1'b1; |
Read_To_Reg = 1'b1; |
Save_ALU = 1'b1; |
ALU_Op = 4'b0001; |
Set_BusA_To[2:0] = 3'b100; |
case (IR[5:4]) |
0,1,2 : |
begin |
Set_BusB_To[2:1] = IR[5:4]; |
Set_BusB_To[0] = 1'b0; |
end |
default : |
Set_BusB_To = 4'b1001; |
endcase // case(IR[5:4]) |
end // case: 3 |
|
default :; |
endcase // case(MCycle) |
end // case: 8'b01001010,8'b01011010,8'b01101010,8'b01111010 |
|
8'b01000010,8'b01010010,8'b01100010,8'b01110010 : |
begin |
// SBC HL,ss |
MCycles = 3'b011; |
case (1'b1) // MCycle |
MCycle[1] : |
begin |
NoRead = 1'b1; |
ALU_Op = 4'b0011; |
Read_To_Reg = 1'b1; |
Save_ALU = 1'b1; |
Set_BusA_To[2:0] = 3'b101; |
case (IR[5:4]) |
0,1,2 : |
begin |
Set_BusB_To[2:1] = IR[5:4]; |
Set_BusB_To[0] = 1'b1; |
end |
default : |
Set_BusB_To = 4'b1000; |
endcase |
TStates = 3'b100; |
end // case: 2 |
|
MCycle[2] : |
begin |
NoRead = 1'b1; |
ALU_Op = 4'b0011; |
Read_To_Reg = 1'b1; |
Save_ALU = 1'b1; |
Set_BusA_To[2:0] = 3'b100; |
case (IR[5:4]) |
0,1,2 : |
Set_BusB_To[2:1] = IR[5:4]; |
default : |
Set_BusB_To = 4'b1001; |
endcase |
end // case: 3 |
|
default :; |
|
endcase // case(MCycle) |
end // case: 8'b01000010,8'b01010010,8'b01100010,8'b01110010 |
|
8'b01101111 : |
begin |
// RLD |
MCycles = 3'b100; |
case (1'b1) // MCycle |
MCycle[1] : |
begin |
NoRead = 1'b1; |
Set_Addr_To = aXY; |
end |
|
MCycle[2] : |
begin |
Read_To_Reg = 1'b1; |
Set_BusB_To[2:0] = 3'b110; |
Set_BusA_To[2:0] = 3'b111; |
ALU_Op = 4'b1101; |
TStates = 3'b100; |
Set_Addr_To = aXY; |
Save_ALU = 1'b1; |
end |
|
MCycle[3] : |
begin |
I_RLD = 1'b1; |
Write = 1'b1; |
end |
|
default :; |
endcase // case(MCycle) |
end // case: 8'b01101111 |
|
8'b01100111 : |
begin |
// RRD |
MCycles = 3'b100; |
case (1'b1) // MCycle |
MCycle[1] : |
Set_Addr_To = aXY; |
MCycle[2] : |
begin |
Read_To_Reg = 1'b1; |
Set_BusB_To[2:0] = 3'b110; |
Set_BusA_To[2:0] = 3'b111; |
ALU_Op = 4'b1110; |
TStates = 3'b100; |
Set_Addr_To = aXY; |
Save_ALU = 1'b1; |
end |
|
MCycle[3] : |
begin |
I_RRD = 1'b1; |
Write = 1'b1; |
end |
|
default :; |
endcase // case(MCycle) |
end // case: 8'b01100111 |
|
8'b01xxx101 : |
begin |
// RETI, RETN |
MCycles = 3'b011; |
case (1'b1) // MCycle |
MCycle[0] : |
Set_Addr_To = aSP; |
|
MCycle[1] : |
begin |
IncDec_16 = 4'b0111; |
Set_Addr_To = aSP; |
LDZ = 1'b1; |
end |
|
MCycle[2] : |
begin |
Jump = 1'b1; |
IncDec_16 = 4'b0111; |
I_RETN = 1'b1; |
end |
|
default :; |
endcase // case(MCycle) |
end // case: 8'b01000101,8'b01001101,8'b01010101,8'b01011101,8'b01100101,8'b01101101,8'b01110101,8'b01111101 |
|
8'b01xxx000 : |
begin |
// IN r,(C) |
MCycles = 3'b010; |
case (1'b1) // MCycle |
MCycle[0] : |
Set_Addr_To = aBC; |
|
MCycle[1] : |
begin |
IORQ = 1'b1; |
if (IR[5:3] != 3'b110 ) |
begin |
Read_To_Reg = 1'b1; |
Set_BusA_To[2:0] = IR[5:3]; |
end |
I_INRC = 1'b1; |
end |
|
default :; |
endcase // case(MCycle) |
end // case: 8'b01000000,8'b01001000,8'b01010000,8'b01011000,8'b01100000,8'b01101000,8'b01110000,8'b01111000 |
|
8'b01xxx001 : |
begin |
// OUT (C),r |
// OUT (C),0 |
MCycles = 3'b010; |
case (1'b1) // MCycle |
MCycle[0] : |
begin |
Set_Addr_To = aBC; |
Set_BusB_To[2:0] = IR[5:3]; |
if (IR[5:3] == 3'b110 ) |
begin |
Set_BusB_To[3] = 1'b1; |
end |
end |
|
MCycle[1] : |
begin |
Write = 1'b1; |
IORQ = 1'b1; |
end |
|
default :; |
endcase // case(MCycle) |
end // case: 8'b01000001,8'b01001001,8'b01010001,8'b01011001,8'b01100001,8'b01101001,8'b01110001,8'b01111001 |
|
8'b10100010 , 8'b10101010 , 8'b10110010 , 8'b10111010 : |
begin |
// INI, IND, INIR, INDR |
MCycles = 3'b100; |
case (1'b1) // MCycle |
MCycle[0] : |
begin |
Set_Addr_To = aBC; |
Set_BusB_To = 4'b1010; |
Set_BusA_To = 4'b0000; |
Read_To_Reg = 1'b1; |
Save_ALU = 1'b1; |
ALU_Op = 4'b0010; |
end |
|
MCycle[1] : |
begin |
IORQ = 1'b1; |
Set_BusB_To = 4'b0110; |
Set_Addr_To = aXY; |
end |
|
MCycle[2] : |
begin |
if (IR[3] == 1'b0 ) |
begin |
IncDec_16 = 4'b0110; |
end |
else |
begin |
IncDec_16 = 4'b1110; |
end |
TStates = 3'b100; |
Write = 1'b1; |
I_BTR = 1'b1; |
end // case: 3 |
|
MCycle[3] : |
begin |
NoRead = 1'b1; |
TStates = 3'b101; |
end |
|
default :; |
endcase // case(MCycle) |
end // case: 8'b10100010 , 8'b10101010 , 8'b10110010 , 8'b10111010 |
|
8'b10100011 , 8'b10101011 , 8'b10110011 , 8'b10111011 : |
begin |
// OUTI, OUTD, OTIR, OTDR |
MCycles = 3'b100; |
case (1'b1) // MCycle |
MCycle[0] : |
begin |
TStates = 3'b101; |
Set_Addr_To = aXY; |
Set_BusB_To = 4'b1010; |
Set_BusA_To = 4'b0000; |
Read_To_Reg = 1'b1; |
Save_ALU = 1'b1; |
ALU_Op = 4'b0010; |
end |
|
MCycle[1] : |
begin |
Set_BusB_To = 4'b0110; |
Set_Addr_To = aBC; |
if (IR[3] == 1'b0 ) |
begin |
IncDec_16 = 4'b0110; |
end |
else |
begin |
IncDec_16 = 4'b1110; |
end |
end |
|
MCycle[2] : |
begin |
if (IR[3] == 1'b0 ) |
begin |
IncDec_16 = 4'b0010; |
end |
else |
begin |
IncDec_16 = 4'b1010; |
end |
IORQ = 1'b1; |
Write = 1'b1; |
I_BTR = 1'b1; |
end // case: 3 |
|
MCycle[3] : |
begin |
NoRead = 1'b1; |
TStates = 3'b101; |
end |
|
default :; |
endcase // case(MCycle) |
end // case: 8'b10100011 , 8'b10101011 , 8'b10110011 , 8'b10111011 |
|
default : ; |
|
endcase // case(IRB) |
|
end // always @ (IR, ISet, MCycle, F, NMICycle, IntCycle) |
|
assign output_vector = { MCycles, |
TStates, |
Prefix, |
Inc_PC, |
Inc_WZ, |
IncDec_16, |
Read_To_Reg, |
Read_To_Acc, |
Set_BusA_To, |
Set_BusB_To, |
ALU_Op, |
Save_ALU, |
PreserveC, |
Arith16, |
Set_Addr_To, |
IORQ, |
Jump, |
JumpE, |
JumpXY, |
Call, |
RstP, |
LDZ, |
LDW, |
LDSPHL, |
Special_LD, |
ExchangeDH, |
ExchangeRp, |
ExchangeAF, |
ExchangeRS, |
I_DJNZ, |
I_CPL, |
I_CCF, |
I_SCF, |
I_RETN, |
I_BT, |
I_BC, |
I_BTR, |
I_RLD, |
I_RRD, |
I_INRC, |
SetDI, |
SetEI, |
IMode, |
Halt, |
NoRead, |
Write }; |
|
// synopsys dc_script_begin |
// set_attribute current_design "revision" "$Id: tv80_mcode_ed.v,v 1.1.2.1 2004-11-30 21:58:10 ghutchis Exp $" -type string -quiet |
// synopsys dc_script_end |
endmodule // T80_MCode |
/core/tv80n.v
0,0 → 1,182
// |
// TV80 8-Bit Microprocessor Core |
// Based on the VHDL T80 core by Daniel Wallner (jesus@opencores.org) |
// |
// Copyright (c) 2004 Guy Hutchison (ghutchis@opencores.org) |
// |
// Permission is hereby granted, free of charge, to any person obtaining a |
// copy of this software and associated documentation files (the "Software"), |
// to deal in the Software without restriction, including without limitation |
// the rights to use, copy, modify, merge, publish, distribute, sublicense, |
// and/or sell copies of the Software, and to permit persons to whom the |
// Software is furnished to do so, subject to the following conditions: |
// |
// The above copyright notice and this permission notice shall be included |
// in all copies or substantial portions of the Software. |
// |
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, |
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. |
// IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY |
// CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, |
// TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE |
// SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. |
|
// Negative-edge based wrapper allows memory wait_n signal to work |
// correctly without resorting to asynchronous logic. |
|
module tv80n (/*AUTOARG*/ |
// Outputs |
m1_n, mreq_n, iorq_n, rd_n, wr_n, rfsh_n, halt_n, busak_n, A, do, |
// Inputs |
reset_n, clk, wait_n, int_n, nmi_n, busrq_n, di |
); |
|
parameter Mode = 0; // 0 => Z80, 1 => Fast Z80, 2 => 8080, 3 => GB |
parameter T2Write = 0; // 0 => wr_n active in T3, /=0 => wr_n active in T2 |
parameter IOWait = 1; // 0 => Single cycle I/O, 1 => Std I/O cycle |
|
|
input reset_n; |
input clk; |
input wait_n; |
input int_n; |
input nmi_n; |
input busrq_n; |
output m1_n; |
output mreq_n; |
output iorq_n; |
output rd_n; |
output wr_n; |
output rfsh_n; |
output halt_n; |
output busak_n; |
output [15:0] A; |
input [7:0] di; |
output [7:0] do; |
|
reg mreq_n; |
reg iorq_n; |
reg rd_n; |
reg wr_n; |
reg nxt_mreq_n; |
reg nxt_iorq_n; |
reg nxt_rd_n; |
reg nxt_wr_n; |
|
wire cen; |
wire intcycle_n; |
wire no_read; |
wire write; |
wire iorq; |
reg [7:0] di_reg; |
wire [6:0] mcycle; |
wire [6:0] tstate; |
|
assign cen = 1; |
|
tv80_core #(Mode, IOWait) i_tv80_core |
( |
.cen (cen), |
.m1_n (m1_n), |
.iorq (iorq), |
.no_read (no_read), |
.write (write), |
.rfsh_n (rfsh_n), |
.halt_n (halt_n), |
.wait_n (wait_n), |
.int_n (int_n), |
.nmi_n (nmi_n), |
.reset_n (reset_n), |
.busrq_n (busrq_n), |
.busak_n (busak_n), |
.clk (clk), |
.IntE (), |
.stop (), |
.A (A), |
.dinst (di), |
.di (di_reg), |
.do (do), |
.mc (mcycle), |
.ts (tstate), |
.intcycle_n (intcycle_n) |
); |
|
always @* |
begin |
nxt_mreq_n = 1; |
nxt_rd_n = 1; |
nxt_iorq_n = 1; |
nxt_wr_n = 1; |
|
if (mcycle[0]) |
begin |
if (tstate[1] || tstate[2]) |
begin |
nxt_rd_n = ~ intcycle_n; |
nxt_mreq_n = ~ intcycle_n; |
nxt_iorq_n = intcycle_n; |
end |
end // if (mcycle[0]) |
else |
begin |
if ((tstate[1] || tstate[2]) && !no_read && !write) |
begin |
nxt_rd_n = 1'b0; |
nxt_iorq_n = ~ iorq; |
nxt_mreq_n = iorq; |
end |
if (T2Write == 0) |
begin |
if (tstate[2] && write) |
begin |
nxt_wr_n = 1'b0; |
nxt_iorq_n = ~ iorq; |
nxt_mreq_n = iorq; |
end |
end |
else |
begin |
if ((tstate[1] || (tstate[2] && !wait_n)) && write) |
begin |
nxt_wr_n = 1'b0; |
nxt_iorq_n = ~ iorq; |
nxt_mreq_n = iorq; |
end |
end // else: !if(T2write == 0) |
end // else: !if(mcycle[0]) |
end // always @ * |
|
always @(negedge clk) |
begin |
if (!reset_n) |
begin |
rd_n <= #1 1'b1; |
wr_n <= #1 1'b1; |
iorq_n <= #1 1'b1; |
mreq_n <= #1 1'b1; |
end |
else |
begin |
rd_n <= #1 nxt_rd_n; |
wr_n <= #1 nxt_wr_n; |
iorq_n <= #1 nxt_iorq_n; |
mreq_n <= #1 nxt_mreq_n; |
end // else: !if(!reset_n) |
end // always @ (posedge clk or negedge reset_n) |
|
always @(posedge clk) |
begin |
if (!reset_n) |
begin |
di_reg <= #1 0; |
end |
else |
begin |
if (tstate[2] && wait_n == 1'b1) |
di_reg <= #1 di; |
end // else: !if(!reset_n) |
end // always @ (posedge clk) |
|
endmodule // t80n |
|
/core/tv80s.v
0,0 → 1,160
// |
// TV80 8-Bit Microprocessor Core |
// Based on the VHDL T80 core by Daniel Wallner (jesus@opencores.org) |
// |
// Copyright (c) 2004 Guy Hutchison (ghutchis@opencores.org) |
// |
// Permission is hereby granted, free of charge, to any person obtaining a |
// copy of this software and associated documentation files (the "Software"), |
// to deal in the Software without restriction, including without limitation |
// the rights to use, copy, modify, merge, publish, distribute, sublicense, |
// and/or sell copies of the Software, and to permit persons to whom the |
// Software is furnished to do so, subject to the following conditions: |
// |
// The above copyright notice and this permission notice shall be included |
// in all copies or substantial portions of the Software. |
// |
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, |
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. |
// IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY |
// CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, |
// TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE |
// SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. |
|
module tv80s (/*AUTOARG*/ |
// Outputs |
m1_n, mreq_n, iorq_n, rd_n, wr_n, rfsh_n, halt_n, busak_n, A, do, |
// Inputs |
reset_n, clk, wait_n, int_n, nmi_n, busrq_n, di |
); |
|
parameter Mode = 0; // 0 => Z80, 1 => Fast Z80, 2 => 8080, 3 => GB |
parameter T2Write = 0; // 0 => wr_n active in T3, /=0 => wr_n active in T2 |
parameter IOWait = 1; // 0 => Single cycle I/O, 1 => Std I/O cycle |
|
|
input reset_n; |
input clk; |
input wait_n; |
input int_n; |
input nmi_n; |
input busrq_n; |
output m1_n; |
output mreq_n; |
output iorq_n; |
output rd_n; |
output wr_n; |
output rfsh_n; |
output halt_n; |
output busak_n; |
output [15:0] A; |
input [7:0] di; |
output [7:0] do; |
|
reg mreq_n; |
reg iorq_n; |
reg rd_n; |
reg wr_n; |
|
wire cen; |
wire intcycle_n; |
wire no_read; |
wire write; |
wire iorq; |
reg [7:0] di_reg; |
wire [6:0] mcycle; |
wire [6:0] tstate; |
|
assign cen = 1; |
|
tv80_core #(Mode, IOWait) i_tv80_core |
( |
.cen (cen), |
.m1_n (m1_n), |
.iorq (iorq), |
.no_read (no_read), |
.write (write), |
.rfsh_n (rfsh_n), |
.halt_n (halt_n), |
.wait_n (wait_n), |
.int_n (int_n), |
.nmi_n (nmi_n), |
.reset_n (reset_n), |
.busrq_n (busrq_n), |
.busak_n (busak_n), |
.clk (clk), |
.IntE (), |
.stop (), |
.A (A), |
.dinst (di), |
.di (di_reg), |
.do (do), |
.mc (mcycle), |
.ts (tstate), |
.intcycle_n (intcycle_n) |
); |
|
always @(posedge clk) |
begin |
if (!reset_n) |
begin |
rd_n <= #1 1'b1; |
wr_n <= #1 1'b1; |
iorq_n <= #1 1'b1; |
mreq_n <= #1 1'b1; |
di_reg <= #1 0; |
end |
else |
begin |
rd_n <= #1 1'b1; |
wr_n <= #1 1'b1; |
iorq_n <= #1 1'b1; |
mreq_n <= #1 1'b1; |
if (mcycle[0]) |
begin |
if (tstate[1] || (tstate[2] && wait_n == 1'b0)) |
begin |
rd_n <= #1 ~ intcycle_n; |
mreq_n <= #1 ~ intcycle_n; |
iorq_n <= #1 intcycle_n; |
end |
if (tstate[3]) |
mreq_n <= #1 1'b0; |
end // if (mcycle[0]) |
else |
begin |
if ((tstate[1] || (tstate[2] && wait_n == 1'b0)) && no_read == 1'b0 && write == 1'b0) |
begin |
rd_n <= #1 1'b0; |
iorq_n <= #1 ~ iorq; |
mreq_n <= #1 iorq; |
end |
if (T2Write == 0) |
begin |
if (tstate[2] && write == 1'b1) |
begin |
wr_n <= #1 1'b0; |
iorq_n <= #1 ~ iorq; |
mreq_n <= #1 iorq; |
end |
end |
else |
begin |
if ((tstate[1] || (tstate[2] && wait_n == 1'b0)) && write == 1'b1) |
begin |
wr_n <= #1 1'b0; |
iorq_n <= #1 ~ iorq; |
mreq_n <= #1 iorq; |
end |
end // else: !if(T2write == 0) |
|
end // else: !if(mcycle[0]) |
|
if (tstate[2] && wait_n == 1'b1) |
di_reg <= #1 di; |
end // else: !if(!reset_n) |
end // always @ (posedge clk or negedge reset_n) |
|
endmodule // t80s |
|
/core/tv80_alu.v
0,0 → 1,442
// |
// TV80 8-Bit Microprocessor Core |
// Based on the VHDL T80 core by Daniel Wallner (jesus@opencores.org) |
// |
// Copyright (c) 2004 Guy Hutchison (ghutchis@opencores.org) |
// |
// Permission is hereby granted, free of charge, to any person obtaining a |
// copy of this software and associated documentation files (the "Software"), |
// to deal in the Software without restriction, including without limitation |
// the rights to use, copy, modify, merge, publish, distribute, sublicense, |
// and/or sell copies of the Software, and to permit persons to whom the |
// Software is furnished to do so, subject to the following conditions: |
// |
// The above copyright notice and this permission notice shall be included |
// in all copies or substantial portions of the Software. |
// |
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, |
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. |
// IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY |
// CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, |
// TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE |
// SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. |
|
module tv80_alu (/*AUTOARG*/ |
// Outputs |
Q, F_Out, |
// Inputs |
Arith16, Z16, ALU_Op, IR, ISet, BusA, BusB, F_In |
); |
|
parameter Mode = 0; |
parameter Flag_C = 0; |
parameter Flag_N = 1; |
parameter Flag_P = 2; |
parameter Flag_X = 3; |
parameter Flag_H = 4; |
parameter Flag_Y = 5; |
parameter Flag_Z = 6; |
parameter Flag_S = 7; |
|
input Arith16; |
input Z16; |
input [3:0] ALU_Op ; |
input [5:0] IR; |
input [1:0] ISet; |
input [7:0] BusA; |
input [7:0] BusB; |
input [7:0] F_In; |
output [7:0] Q; |
output [7:0] F_Out; |
reg [7:0] Q; |
reg [7:0] F_Out; |
|
function [4:0] AddSub4; |
input [3:0] A; |
input [3:0] B; |
input Sub; |
input Carry_In; |
begin |
AddSub4 = { 1'b0, A } + { 1'b0, (Sub)?~B:B } + Carry_In; |
end |
endfunction // AddSub4 |
|
function [3:0] AddSub3; |
input [2:0] A; |
input [2:0] B; |
input Sub; |
input Carry_In; |
begin |
AddSub3 = { 1'b0, A } + { 1'b0, (Sub)?~B:B } + Carry_In; |
end |
endfunction // AddSub4 |
|
function [1:0] AddSub1; |
input A; |
input B; |
input Sub; |
input Carry_In; |
begin |
AddSub1 = { 1'b0, A } + { 1'b0, (Sub)?~B:B } + Carry_In; |
end |
endfunction // AddSub4 |
|
// AddSub variables (temporary signals) |
reg UseCarry; |
reg Carry7_v; |
reg OverFlow_v; |
reg HalfCarry_v; |
reg Carry_v; |
reg [7:0] Q_v; |
|
reg [7:0] BitMask; |
|
|
always @(/*AUTOSENSE*/ALU_Op or BusA or BusB or F_In or IR) |
begin |
case (IR[5:3]) |
3'b000 : BitMask = 8'b00000001; |
3'b001 : BitMask = 8'b00000010; |
3'b010 : BitMask = 8'b00000100; |
3'b011 : BitMask = 8'b00001000; |
3'b100 : BitMask = 8'b00010000; |
3'b101 : BitMask = 8'b00100000; |
3'b110 : BitMask = 8'b01000000; |
default: BitMask = 8'b10000000; |
endcase // case(IR[5:3]) |
|
UseCarry = ~ ALU_Op[2] && ALU_Op[0]; |
{ HalfCarry_v, Q_v[3:0] } = AddSub4(BusA[3:0], BusB[3:0], ALU_Op[1], ALU_Op[1] ^ (UseCarry && F_In[Flag_C]) ); |
{ Carry7_v, Q_v[6:4] } = AddSub3(BusA[6:4], BusB[6:4], ALU_Op[1], HalfCarry_v); |
{ Carry_v, Q_v[7] } = AddSub1(BusA[7], BusB[7], ALU_Op[1], Carry7_v); |
OverFlow_v = Carry_v ^ Carry7_v; |
end // always @ * |
|
reg [7:0] Q_t; |
reg [8:0] DAA_Q; |
|
always @ (/*AUTOSENSE*/ALU_Op or Arith16 or BitMask or BusA or BusB |
or Carry_v or F_In or HalfCarry_v or IR or ISet |
or OverFlow_v or Q_v or Z16) |
begin |
Q_t = 8'hxx; |
DAA_Q = {9{1'bx}}; |
|
F_Out = F_In; |
case (ALU_Op) |
4'b0000, 4'b0001, 4'b0010, 4'b0011, 4'b0100, 4'b0101, 4'b0110, 4'b0111 : |
begin |
F_Out[Flag_N] = 1'b0; |
F_Out[Flag_C] = 1'b0; |
|
case (ALU_Op[2:0]) |
|
3'b000, 3'b001 : // ADD, ADC |
begin |
Q_t = Q_v; |
F_Out[Flag_C] = Carry_v; |
F_Out[Flag_H] = HalfCarry_v; |
F_Out[Flag_P] = OverFlow_v; |
end |
|
3'b010, 3'b011, 3'b111 : // SUB, SBC, CP |
begin |
Q_t = Q_v; |
F_Out[Flag_N] = 1'b1; |
F_Out[Flag_C] = ~ Carry_v; |
F_Out[Flag_H] = ~ HalfCarry_v; |
F_Out[Flag_P] = OverFlow_v; |
end |
|
3'b100 : // AND |
begin |
Q_t[7:0] = BusA & BusB; |
F_Out[Flag_H] = 1'b1; |
end |
|
3'b101 : // XOR |
begin |
Q_t[7:0] = BusA ^ BusB; |
F_Out[Flag_H] = 1'b0; |
end |
|
default : // OR 3'b110 |
begin |
Q_t[7:0] = BusA | BusB; |
F_Out[Flag_H] = 1'b0; |
end |
|
endcase // case(ALU_OP[2:0]) |
|
if (ALU_Op[2:0] == 3'b111 ) |
begin // CP |
F_Out[Flag_X] = BusB[3]; |
F_Out[Flag_Y] = BusB[5]; |
end |
else |
begin |
F_Out[Flag_X] = Q_t[3]; |
F_Out[Flag_Y] = Q_t[5]; |
end |
|
if (Q_t[7:0] == 8'b00000000 ) |
begin |
F_Out[Flag_Z] = 1'b1; |
if (Z16 == 1'b1 ) |
begin |
F_Out[Flag_Z] = F_In[Flag_Z]; // 16 bit ADC,SBC |
end |
end |
else |
begin |
F_Out[Flag_Z] = 1'b0; |
end // else: !if(Q_t[7:0] == 8'b00000000 ) |
|
F_Out[Flag_S] = Q_t[7]; |
case (ALU_Op[2:0]) |
3'b000, 3'b001, 3'b010, 3'b011, 3'b111 : // ADD, ADC, SUB, SBC, CP |
; |
|
default : |
F_Out[Flag_P] = ~(^Q_t); |
endcase // case(ALU_Op[2:0]) |
|
if (Arith16 == 1'b1 ) |
begin |
F_Out[Flag_S] = F_In[Flag_S]; |
F_Out[Flag_Z] = F_In[Flag_Z]; |
F_Out[Flag_P] = F_In[Flag_P]; |
end |
end // case: 4'b0000, 4'b0001, 4'b0010, 4'b0011, 4'b0100, 4'b0101, 4'b0110, 4'b0111 |
|
4'b1100 : |
begin |
// DAA |
F_Out[Flag_H] = F_In[Flag_H]; |
F_Out[Flag_C] = F_In[Flag_C]; |
DAA_Q[7:0] = BusA; |
DAA_Q[8] = 1'b0; |
if (F_In[Flag_N] == 1'b0 ) |
begin |
// After addition |
// Alow > 9 || H == 1 |
if (DAA_Q[3:0] > 9 || F_In[Flag_H] == 1'b1 ) |
begin |
if ((DAA_Q[3:0] > 9) ) |
begin |
F_Out[Flag_H] = 1'b1; |
end |
else |
begin |
F_Out[Flag_H] = 1'b0; |
end |
DAA_Q = DAA_Q + 6; |
end // if (DAA_Q[3:0] > 9 || F_In[Flag_H] == 1'b1 ) |
|
// new Ahigh > 9 || C == 1 |
if (DAA_Q[8:4] > 9 || F_In[Flag_C] == 1'b1 ) |
begin |
DAA_Q = DAA_Q + 96; // 0x60 |
end |
end |
else |
begin |
// After subtraction |
if (DAA_Q[3:0] > 9 || F_In[Flag_H] == 1'b1 ) |
begin |
if (DAA_Q[3:0] > 5 ) |
begin |
F_Out[Flag_H] = 1'b0; |
end |
DAA_Q[7:0] = DAA_Q[7:0] - 6; |
end |
if (BusA > 153 || F_In[Flag_C] == 1'b1 ) |
begin |
DAA_Q = DAA_Q - 352; // 0x160 |
end |
end // else: !if(F_In[Flag_N] == 1'b0 ) |
|
F_Out[Flag_X] = DAA_Q[3]; |
F_Out[Flag_Y] = DAA_Q[5]; |
F_Out[Flag_C] = F_In[Flag_C] || DAA_Q[8]; |
Q_t = DAA_Q[7:0]; |
|
if (DAA_Q[7:0] == 8'b00000000 ) |
begin |
F_Out[Flag_Z] = 1'b1; |
end |
else |
begin |
F_Out[Flag_Z] = 1'b0; |
end |
|
F_Out[Flag_S] = DAA_Q[7]; |
F_Out[Flag_P] = ~ (^DAA_Q); |
end // case: 4'b1100 |
|
4'b1101, 4'b1110 : |
begin |
// RLD, RRD |
Q_t[7:4] = BusA[7:4]; |
if (ALU_Op[0] == 1'b1 ) |
begin |
Q_t[3:0] = BusB[7:4]; |
end |
else |
begin |
Q_t[3:0] = BusB[3:0]; |
end |
F_Out[Flag_H] = 1'b0; |
F_Out[Flag_N] = 1'b0; |
F_Out[Flag_X] = Q_t[3]; |
F_Out[Flag_Y] = Q_t[5]; |
if (Q_t[7:0] == 8'b00000000 ) |
begin |
F_Out[Flag_Z] = 1'b1; |
end |
else |
begin |
F_Out[Flag_Z] = 1'b0; |
end |
F_Out[Flag_S] = Q_t[7]; |
F_Out[Flag_P] = ~(^Q_t); |
end // case: when 4'b1101, 4'b1110 |
|
4'b1001 : |
begin |
// BIT |
Q_t[7:0] = BusB & BitMask; |
F_Out[Flag_S] = Q_t[7]; |
if (Q_t[7:0] == 8'b00000000 ) |
begin |
F_Out[Flag_Z] = 1'b1; |
F_Out[Flag_P] = 1'b1; |
end |
else |
begin |
F_Out[Flag_Z] = 1'b0; |
F_Out[Flag_P] = 1'b0; |
end |
F_Out[Flag_H] = 1'b1; |
F_Out[Flag_N] = 1'b0; |
F_Out[Flag_X] = 1'b0; |
F_Out[Flag_Y] = 1'b0; |
if (IR[2:0] != 3'b110 ) |
begin |
F_Out[Flag_X] = BusB[3]; |
F_Out[Flag_Y] = BusB[5]; |
end |
end // case: when 4'b1001 |
|
4'b1010 : |
// SET |
Q_t[7:0] = BusB | BitMask; |
|
4'b1011 : |
// RES |
Q_t[7:0] = BusB & ~ BitMask; |
|
4'b1000 : |
begin |
// ROT |
case (IR[5:3]) |
3'b000 : // RLC |
begin |
Q_t[7:1] = BusA[6:0]; |
Q_t[0] = BusA[7]; |
F_Out[Flag_C] = BusA[7]; |
end |
|
3'b010 : // RL |
begin |
Q_t[7:1] = BusA[6:0]; |
Q_t[0] = F_In[Flag_C]; |
F_Out[Flag_C] = BusA[7]; |
end |
|
3'b001 : // RRC |
begin |
Q_t[6:0] = BusA[7:1]; |
Q_t[7] = BusA[0]; |
F_Out[Flag_C] = BusA[0]; |
end |
|
3'b011 : // RR |
begin |
Q_t[6:0] = BusA[7:1]; |
Q_t[7] = F_In[Flag_C]; |
F_Out[Flag_C] = BusA[0]; |
end |
|
3'b100 : // SLA |
begin |
Q_t[7:1] = BusA[6:0]; |
Q_t[0] = 1'b0; |
F_Out[Flag_C] = BusA[7]; |
end |
|
3'b110 : // SLL (Undocumented) / SWAP |
begin |
if (Mode == 3 ) |
begin |
Q_t[7:4] = BusA[3:0]; |
Q_t[3:0] = BusA[7:4]; |
F_Out[Flag_C] = 1'b0; |
end |
else |
begin |
Q_t[7:1] = BusA[6:0]; |
Q_t[0] = 1'b1; |
F_Out[Flag_C] = BusA[7]; |
end // else: !if(Mode == 3 ) |
end // case: 3'b110 |
|
3'b101 : // SRA |
begin |
Q_t[6:0] = BusA[7:1]; |
Q_t[7] = BusA[7]; |
F_Out[Flag_C] = BusA[0]; |
end |
|
default : // SRL |
begin |
Q_t[6:0] = BusA[7:1]; |
Q_t[7] = 1'b0; |
F_Out[Flag_C] = BusA[0]; |
end |
endcase // case(IR[5:3]) |
|
F_Out[Flag_H] = 1'b0; |
F_Out[Flag_N] = 1'b0; |
F_Out[Flag_X] = Q_t[3]; |
F_Out[Flag_Y] = Q_t[5]; |
F_Out[Flag_S] = Q_t[7]; |
if (Q_t[7:0] == 8'b00000000 ) |
begin |
F_Out[Flag_Z] = 1'b1; |
end |
else |
begin |
F_Out[Flag_Z] = 1'b0; |
end |
F_Out[Flag_P] = ~(^Q_t); |
|
if (ISet == 2'b00 ) |
begin |
F_Out[Flag_P] = F_In[Flag_P]; |
F_Out[Flag_S] = F_In[Flag_S]; |
F_Out[Flag_Z] = F_In[Flag_Z]; |
end |
end // case: 4'b1000 |
|
|
default : |
; |
|
endcase // case(ALU_Op) |
|
Q = Q_t; |
end // always @ (Arith16, ALU_OP, F_In, BusA, BusB, IR, Q_v, Carry_v, HalfCarry_v, OverFlow_v, BitMask, ISet, Z16) |
|
endmodule // T80_ALU |