Subversion Repositories a-z80

//=========================================================================================

// This file contains substitute strings for macro expansions. Macros are defined in an

// Excel timing spreadsheet 'Timings.xlsm' and exported to a .csv file which is then read

// and processed by genmatrix.py script to generate exec_matrix.vh include file.

//

// Macro format:

//

// * Each key is prefixed by ':' and corresponds to a spreadsheet *column* name.

// * A key may contain several different macros, one per line.

// * A macro may span multiple lines; use the '\' character to continue on the next line.

// * Multi-line macros end when a line does not start with a space character.

// //-style comments are wrapped within /* ... */ if they don't start a line.

//=========================================================================================

//-----------------------------------------------------------------------------------------

// CPU machine state

//-----------------------------------------------------------------------------------------

:Function

//Fetch is M1

fMFetch

fMRead          fMRead=1;

fMWrite         fMWrite=1;

fIORead         fIORead=1;

fIOWrite        fIOWrite=1;

//-----------------------------------------------------------------------------------------

// Basic timing control

//-----------------------------------------------------------------------------------------

:valid

Y               validPLA=1;

:nextM

Y               nextM=1;

mr              nextM=1; ctl_mRead=1;

mw              nextM=1; ctl_mWrite=1;

ior             nextM=1; ctl_iorw=1;

iow             nextM=1; ctl_iorw=1;

CC              nextM=~flags_cond_true;

INT             nextM=1; ctl_mRead=in_intr & im2;   // RST38 interrupt extension

:setM1

Y               setM1=1;

SS              setM1=~flags_cond_true;

CC              setM1=~flags_cond_true;

ZF              setM1=flags_zf;                     // Used in DJNZ

BR              setM1=nonRep | ~repeat_en;

BRZ             setM1=nonRep | ~repeat_en | flags_zf;

BZ              setM1=nonRep | flags_zf;

INT             setM1=~(in_intr & im2);             // RST38 interrupt extension

//-----------------------------------------------------------------------------------------

// Register file, address (downstream) endpoint

//-----------------------------------------------------------------------------------------

:A:reg rd

// General purpose registers

A       ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b10; ctl_sw_4d=1;  // Read 8-bit general purpose A register, enable SW4 downstream

r16     ctl_reg_gp_sel=op54; ctl_reg_gp_hilo=2'b11; ctl_sw_4d=1;        // Read 16-bit general purpose register, enable SW4 downstream

BC      ctl_reg_gp_sel=`GP_REG_BC; ctl_reg_gp_hilo=2'b11; ctl_sw_4d=1;  // Read 16-bit BC, enable SW4 downstream

DE      ctl_reg_gp_sel=`GP_REG_DE; ctl_reg_gp_hilo=2'b11; ctl_sw_4d=1;  // Read 16-bit DE, enable SW4 downstream

HL      ctl_reg_gp_sel=`GP_REG_HL; ctl_reg_gp_hilo=2'b11; ctl_sw_4d=1;  // Read 16-bit HL, enable SW4 downstream

SP      ctl_reg_use_sp=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_sw_4d=1;// Read 16-bit SP, enable SW4 downstream

// System registers

WZ      ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11; ctl_sw_4d=1;          // Select 16-bit WZ

IR      ctl_reg_sel_ir=1; ctl_reg_sys_hilo=2'b11;                       // Select 16-bit IR

I*      ctl_reg_sel_ir=1; ctl_reg_sys_hilo=2'b10; ctl_sw_4d=1;          // Select 8-bit I register

PC      ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11;                       // Select 16-bit PC

// Conditional assertions of WZ, HL instead of PC

WZ?     ctl_reg_not_pc|=flags_cond_true; ctl_reg_sel_wz|=flags_cond_true; ctl_reg_sys_hilo|={flags_cond_true,flags_cond_true}; ctl_sw_4d|=flags_cond_true;

// Alternate format:

//    if (flags_cond_true) begin // If cc is true, use WZ instead of PC (for jumps)

//        ctl_reg_not_pc=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11; ctl_sw_4d=1;

//    end

:A:reg wr

// General purpose registers

r16     ctl_reg_gp_we=1; ctl_reg_gp_sel=op54; ctl_reg_gp_hilo=2'b11; ctl_sw_4u=1; // Write 16-bit general purpose register, enable SW4 upstream

BC      ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_BC; ctl_reg_gp_hilo=2'b11; ctl_sw_4u=1; // Write 16-bit BC, enable SW4 upstream

DE      ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_DE; ctl_reg_gp_hilo=2'b11; ctl_sw_4u=1; // Write 16-bit BC, enable SW4 upstream

HL      ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_HL; ctl_reg_gp_hilo=2'b11; ctl_sw_4u=1; // Write 16-bit HL, enable SW4 upstream

SP      ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11; ctl_reg_use_sp=1; ctl_sw_4u=1; // Write 16-bit SP, enable SW4 upstream

// System registers

WZ      ctl_reg_sys_we=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11; ctl_sw_4u=1; // Write 16-bit WZ, enable SW4 upstream

IR      ctl_reg_sys_we=1; ctl_reg_sel_ir=1; ctl_reg_sys_hilo=2'b11; // Write 16-bit IR

// PC will not be incremented if we are in HALT, INTR or NMI state

PC      ctl_reg_sys_we=1; ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b11; pc_inc_hold=(in_halt | in_intr | in_nmi); // Write 16-bit PC and control incrementer

>       ctl_sw_4u=1;

//-----------------------------------------------------------------------------------------

// Controls the address latch incrementer, the address latch and the address pin mux

//-----------------------------------------------------------------------------------------

:inc/dec

+       ctl_inc_cy=~pc_inc_hold;                      // Increment

-       ctl_inc_cy=~pc_inc_hold; ctl_inc_dec=1;       // Decrement

op3     ctl_inc_cy=~pc_inc_hold; ctl_inc_dec=op3;     // Decrement if op3 is set; increment otherwise

:A:latch

W       ctl_al_we=1;                            // Write a value from the register bus to the address latch

R       ctl_bus_inc_oe=1;                       // Output enable incrementer to the register bus

P       ctl_apin_mux=1;                         // Apin sourced from incrementer

RL      ctl_bus_inc_oe=1; ctl_apin_mux2=1;      // Apin sourced from AL

//-----------------------------------------------------------------------------------------

// Register file, data (upstream) endpoint

//-----------------------------------------------------------------------------------------

:D:reg rd

//----- General purpose registers -----

A       ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b10;

AF      ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b11;

B       ctl_reg_gp_sel=`GP_REG_BC; ctl_reg_gp_hilo=2'b10;

H       ctl_reg_gp_sel=`GP_REG_HL; ctl_reg_gp_hilo=2'b10;

L       ctl_reg_gp_sel=`GP_REG_HL; ctl_reg_gp_hilo=2'b01;

r8      ctl_reg_gp_sel=op21; ctl_reg_gp_hilo={~rsel0,rsel0};// Read 8-bit GP register selected by op[2:0]

r8' \   // r8 addressing does not allow reading F register (indices of A and F are also swapped) (ex. in OUT (c),r)

        if (op4 & op5 & ~op3) begin ctl_bus_zero_oe=1; end  // Trying to read flags? Put 0 on the bus instead.

        if (~(op4 & op5 & ~op3)) begin ctl_reg_gp_sel=op54; ctl_reg_gp_hilo={~rsel3,rsel3}; end // Read 8-bit GP register

rh      ctl_reg_gp_sel=op54; ctl_reg_gp_hilo=2'b10;         // Read 8-bit GP register high byte

rl      ctl_reg_gp_sel=op54; ctl_reg_gp_hilo=2'b01;         // Read 8-bit GP register low byte

//----- System registers -----

WZ      ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11; ctl_sw_4u=1;

Z       ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b01; ctl_sw_4u=1; // Selecting strictly Z

I/R     ctl_reg_sel_ir=1; ctl_reg_sys_hilo={~op3,op3}; ctl_sw_4u=1; // Read either I or R based on op3 (0 or 1)

PCh     ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b10; ctl_sw_4u=1;

PCl     ctl_reg_sel_pc=1; ctl_reg_sys_hilo=2'b01; ctl_sw_4u=1;

:D:reg wr

?       // Which register to be written is decided elsewhere

//----- General purpose registers -----

A       ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b10;

F       ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_AF; ctl_reg_gp_hilo=2'b01;

B       ctl_reg_gp_we=1; ctl_reg_gp_sel=`GP_REG_BC; ctl_reg_gp_hilo=2'b10;

r8      ctl_reg_gp_we=1; ctl_reg_gp_sel=op54; ctl_reg_gp_hilo={~rsel3,rsel3}; // Write 8-bit GP register

r8'     ctl_reg_gp_we=1; ctl_reg_gp_sel=op21; ctl_reg_gp_hilo={~rsel0,rsel0}; // Write 8-bit GP register selected by op[2:0]

rh      ctl_reg_gp_we=1; ctl_reg_gp_sel=op54; ctl_reg_gp_hilo=2'b10; // Write 8-bit GP register high byte

rl      ctl_reg_gp_we=1; ctl_reg_gp_sel=op54; ctl_reg_gp_hilo=2'b01; // Write 8-bit GP register low byte

//----- System registers -----

I/R     ctl_reg_sys_we=1; ctl_reg_sel_ir=1; ctl_reg_sys_hilo={~op3,op3}; ctl_sw_4d=1; // Write either I or R based on op3 (0 or 1)

WZ      ctl_reg_sys_we=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo=2'b11;

W       ctl_reg_sys_we_hi=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo={1'b1,ctl_reg_sys_hilo[0]}; // Selecting only W

W?      ctl_reg_sys_we_hi=flags_cond_true; ctl_reg_sel_wz=flags_cond_true; ctl_reg_sys_hilo={1'b1,ctl_reg_sys_hilo[0]}; // Conditionally selecting only W

Z       ctl_reg_sys_we_lo=1; ctl_reg_sel_wz=1; ctl_reg_sys_hilo={ctl_reg_sys_hilo[1],1'b1}; // Selecting only Z

//-----------------------------------------------------------------------------------------

// Controls the register file gate connecting it with the ALU and data bus

//-----------------------------------------------------------------------------------------

:Reg gate

<       ctl_reg_in_hi=1; ctl_reg_in_lo=1;       // From the ALU side into the register file

>       ctl_reg_out_hi=1; ctl_reg_out_lo=1;     // From the register file into the FLAGT and ALU

// Enables a register gate (high/low) corresponding to the selected 8-bit register

>r8     ctl_reg_out_hi=~rsel0; ctl_reg_out_lo=rsel0; ctl_sw_2u=~rsel0; ctl_sw_2d=rsel0; // Enable register gate based on the rsel0

>r8'    ctl_reg_out_hi=~rsel3; ctl_reg_out_lo=rsel3; ctl_sw_2u=~rsel3; ctl_sw_2d=rsel3; // Enable register gate based on the rsel3

>l      ctl_reg_out_lo=1;                       // From the register file onto the db1 (sw2 + FLAGT + sw1)

>h      ctl_reg_out_hi=1;                       // From the register file onto the db2 (sw2 + ALU)

//-----------------------------------------------------------------------------------------

// Switches on the data bus for each direction (upstream, downstream)

//-----------------------------------------------------------------------------------------

:SW2

d       ctl_sw_2d=1;

u       ctl_sw_2u=1;

-       // Controlled by register gate

:SW1

<       ctl_sw_1d=1;

>       ctl_sw_1u=1;

//-----------------------------------------------------------------------------------------

// Data bus latches and pads control

//-----------------------------------------------------------------------------------------

:DB pads

R       ctl_bus_db_oe=1;                        // Read DB pads to internal data bus

W       ctl_bus_db_we=1;                        // Write DB pads with internal data bus value

00      ctl_bus_zero_oe=1;                      // Force 0x00 on the data bus

FF      ctl_bus_ff_oe=1;                        // Force 0xFF on the data bus

//-----------------------------------------------------------------------------------------

// ALU

//-----------------------------------------------------------------------------------------

:ALU

// Controls the master ALU output enable and the ALU input, only one can be active at a time

// >bs if set, will override >s0 which is used by bit instructions to override default M1/T3 load

<       ctl_alu_oe=1;                           // Enable ALU onto the data bus

>s0     ctl_alu_shift_oe=~ctl_alu_bs_oe;        // Shifter unit without shift-enable

>s1     ctl_alu_shift_oe=1; ctl_shift_en=1;     // Shifter unit AND shift enable!

>bs     ctl_alu_bs_oe=1;                        // Bit-selector unit

:ALU bus

// Controls the writer to the internal ALU bus

op1     ctl_alu_op1_oe=1;                       // OP1 latch

op2     ctl_alu_op2_oe=1;                       // OP2 latch

res     ctl_alu_res_oe=1;                       // Result latch

:op2 latch

// Controls a MUX to select the input to the OP2 latch

bus     ctl_alu_op2_sel_bus=1;                  // Internal bus

lq      ctl_alu_op2_sel_lq=1;                   // Cross-bus wire (see schematic)

:op1 latch

// Controls a MUX to select the input to the OP1 latch

bus     ctl_alu_op1_sel_bus=1;                  // Internal bus

low     ctl_alu_op1_sel_low=1;                  // Write low nibble with a high nibble

:operation

// Defines the ALU core compute operation

// The listing is also showing their alternate formats (using if/then)

//-----------------------------------------------------------------------------------------

CP      ctl_alu_sel_op2_neg=1; ctl_flags_cf_set|=ctl_alu_op_low; ctl_alu_core_hf|=~ctl_alu_op_low;

//    ctl_alu_sel_op2_neg=1;

//    if (ctl_alu_op_low) begin

//        ctl_flags_cf_set=1;

//    end else begin

//        ctl_alu_core_hf=1;

//    end

//-----------------------------------------------------------------------------------------

SUB     ctl_alu_sel_op2_neg=1; ctl_flags_cf_set|=ctl_alu_op_low; ctl_alu_core_hf|=~ctl_alu_op_low;

//    ctl_alu_sel_op2_neg=1;

//    if (ctl_alu_op_low) begin

//        ctl_flags_cf_set=1;

//    end else begin

//        ctl_alu_core_hf=1;

//    end

//-----------------------------------------------------------------------------------------

SBC     ctl_alu_sel_op2_neg=1; ctl_flags_cf_cpl|=ctl_alu_op_low; ctl_alu_core_hf|=~ctl_alu_op_low;

//    ctl_alu_sel_op2_neg=1;

//    if (ctl_alu_op_low) begin

//        ctl_flags_cf_cpl=1;

//    end else begin

//        ctl_alu_core_hf=1;

//    end

//-----------------------------------------------------------------------------------------

SBCh    ctl_alu_sel_op2_neg=1; ctl_alu_core_hf|=~ctl_alu_op_low;

//    ctl_alu_sel_op2_neg=1;

//    if (~ctl_alu_op_low) begin

//        ctl_alu_core_hf=1;

//    end

//-----------------------------------------------------------------------------------------

ADC     ctl_alu_core_hf|=~ctl_alu_op_low;

//    if (~ctl_alu_op_low) begin

//        ctl_alu_core_hf=1;

//    end

//-----------------------------------------------------------------------------------------

ADD     ctl_flags_cf_set|=ctl_alu_op_low; ctl_flags_cf_cpl|=ctl_alu_op_low; ctl_alu_core_hf|=~ctl_alu_op_low;

//    if (ctl_alu_op_low) begin

//        ctl_flags_cf_set=1; ctl_flags_cf_cpl=1;

//    end else begin

//        ctl_alu_core_hf=1;

//    end

//-----------------------------------------------------------------------------------------

AND     ctl_alu_core_S=1; ctl_flags_cf_set=1;

OR      ctl_alu_core_R=1; ctl_alu_core_V=1; ctl_alu_core_S=1; ctl_flags_cf_set=1; ctl_flags_cf_cpl=1;

XOR     ctl_alu_core_R=1; ctl_flags_cf_set=1; ctl_flags_cf_cpl=1;

NAND    ctl_alu_core_S=1; ctl_flags_cf_set=1; ctl_alu_sel_op2_neg=1;

NOR     ctl_alu_core_R=1; ctl_alu_core_V=1; ctl_alu_core_S=1; ctl_flags_cf_set=1; ctl_flags_cf_cpl=1; ctl_alu_sel_op2_neg=1;

//-----------------------------------------------------------------------------------------

PLA     ctl_state_alu=1;                        // Assert the ALU PLA modifier to determine operation

:nibble

// ALU compute phase: working on low nibble or high nibble

L       ctl_alu_op_low=1;                       // Activate ALU operation on low nibble

H       ctl_alu_sel_op2_high=1;                 // Activate ALU operation on high nibble

//-----------------------------------------------------------------------------------------

// FLAGT

//-----------------------------------------------------------------------------------------

:FLAGT

<       ctl_flags_oe=1;                         // Enable FLAGT onto the data bus

>       ctl_flags_bus=1;                        // Load FLAGT from the data bus

alu     ctl_flags_alu=1;                        // Load FLAGT from the ALU

// Write enables for various flag bits and segments

:SZ

*       ctl_flags_sz_we=1;

:XY

*       ctl_flags_xy_we=1;

?

:HF

*       ctl_flags_hf_we=1;

W2      ctl_flags_hf2_we=1;                     // Write HF2 flag (DAA only)

:PF

*       ctl_flags_pf_we=1;

P       ctl_flags_pf_we=1; ctl_pf_sel=`PFSEL_P;

V       ctl_flags_pf_we=1; ctl_pf_sel=`PFSEL_V;

iff2    ctl_flags_pf_we=1; ctl_pf_sel=`PFSEL_IFF2;

REP     ctl_flags_pf_we=1; ctl_pf_sel=`PFSEL_REP;

?

:NF

*       ctl_flags_nf_we=1;                      // Previous NF, to be used when loading FLAGT

1       ctl_flags_nf_we=1; ctl_flags_nf_set=1;

S       ctl_flags_nf_we=1;                      // Sign bit, to be used with FLAGT source set to "alu"

?

:CF

*       ctl_flags_cf_we=1;

1       ctl_flags_cf_set=1;                     // Set CF going into the ALU core

^       ctl_flags_cf_we=1;  ctl_flags_cf_cpl=1; // CCF

:CF2

R       ctl_flags_use_cf2=1;

W       ctl_flags_cf2_we=1;

W.sh    ctl_flags_cf2_we=1; ctl_flags_cf2_sel_shift=1;

W.daa   ctl_flags_cf2_we=1; ctl_flags_cf2_sel_daa=1;

//------------------------------------------------------------------------------------------

// Macros for some special cases; also simplifies control logic for a number of instructions

//------------------------------------------------------------------------------------------

:Special

USE_SP          ctl_reg_use_sp=1;                           // For 16-bit loads: use SP instead of AF

// A few more specific states and instructions:

Ex_DE_HL        ctl_reg_ex_de_hl=1;                         // EX DE,HL

Ex_AF_AF'       ctl_reg_ex_af=1;                            // EX AF,AF'

EXX             ctl_reg_exx=1;                              // EXX

HALT            ctl_state_halt_set=1;                       // Enter HALT state

DI_EI           ctl_iffx_bit=op3; ctl_iffx_we=1;            // DI/EI

IM              ctl_im_we=1;                                // IM n ('n' is read by opcode[4:3])

WZ=IX+d         ixy_d=1;                                    // Compute WZ=IX+d

IX_IY           ctl_state_ixiy_we=1; ctl_state_iy_set=op5; setIXIY=1;   // IX/IY prefix

CLR_IX_IY       ctl_state_ixiy_we=1; ctl_state_ixiy_clr=~setIXIY;       // Clear IX/IY flag if not explicitly set

CB              ctl_state_tbl_we=1; ctl_state_tbl_cb_set=1; // CB-table prefix

ED              ctl_state_tbl_we=1; ctl_state_tbl_ed_set=1; // ED-table prefix

CLR_CB_ED       ctl_state_tbl_we=1;                         // Clear CB/ED prefix if not explicitly set

// If the NF is set, complement HF and CF on the way out to the bus

// This is used to correctly set those flags after subtraction operations

?NF_HF_CF       ctl_flags_hf_cpl=flags_nf; ctl_flags_cf_cpl=flags_nf;

?NF_HF          ctl_flags_hf_cpl=flags_nf;

?~CF_HF         ctl_flags_hf_cpl=~flags_cf;  // Used for CCF

?SF_NEG         ctl_alu_sel_op2_neg=flags_sf;

NEG_OP2         ctl_alu_sel_op2_neg=1;

?NF_SUB         ctl_alu_sel_op2_neg=flags_nf; ctl_flags_cf_cpl=~flags_nf;

// M1 opcode read cycle and the refresh register increment cycle

// Write opcode into the instruction register through internal db0 bus:

OpcodeToIR      ctl_ir_we=1;

// At the common instruction load M1/T3, override opcode byte when servicing interrupts:

// 1. We are in HALT mode: push NOP (0x00) instead

// 2. We are in INTR mode (IM1 or IM2): push RST38 (0xFF) instead

// 3. We are in NMI mode: push RST38 (0xFF) instead

OverrideIR      ctl_bus_zero_oe=in_halt; ctl_bus_ff_oe=(in_intr & (im1 | im2)) | in_nmi;

// RST instruction uses opcode[5:3] to specify a vector and this macro passes those 3 bits through

MASK_543        ctl_sw_mask543_en=~((in_intr & im2) | in_nmi);

// Based on the in_nmi state:

// 1. Disable SW1 so the opcode will not get onto db1 bus

// 2. Generate 0x66 on the db1 bus which will be used as the target vector address

// 3. Clear IFF1 (done by the nmi logic on posedge of in_nmi)

RST_NMI         ctl_sw_1d=~in_nmi; ctl_66_oe=in_nmi;

// Based on the in_intr state:

// 1. IM1 mode, force 0xFF on the db0 bus

// 2. Clear IFF1 and IFF2 (done by the intr logic on posedge of in_intr)

RST_INT         ctl_bus_ff_oe=in_intr & im1;

RETN            ctl_iff1_iff2=1;                // RETN copies IFF2 into IFF1

NO_INTS         ctl_no_ints=1;                  // Disable interrupt generation for this opcode (DI/EI/CB/ED/DD/FD)

EvalCond        ctl_eval_cond=1;                // Evaluate flags condition based on the opcode[5:3]

CondShort       ctl_cond_short=1;               // M1/T3 only: force a short flags condition (SS)

Limit6          ctl_inc_limit6=1;               // Limit the incrementer to 6 bits

DAA             ctl_daa_oe=1;                   // Write DAA correction factor to the bus

ZERO_16BIT      ctl_alu_zero_16bit=1;           // 16-bit arithmetic operation uses ZF calculated over 2 bytes

NonRep          nonRep=1;                       // Non-repeating block instruction

WriteBC=1       ctl_repeat_we=1;                // Update repeating flag latch with BC=1 status

NOT_PC!         ctl_reg_not_pc=1;               // For M1/T1 load from a register other than PC