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URL https://opencores.org/ocsvn/open8_urisc/open8_urisc/trunk

Subversion Repositories open8_urisc

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    /open8_urisc
    from Rev 277 to Rev 278
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Rev 277 → Rev 278

/trunk/VHDL/sdlc_serial_arbfsm.vhd File deleted
/trunk/VHDL/sdlc_serial_txfsm.vhd File deleted \ No newline at end of file
/trunk/VHDL/sdlc_serial_clk.vhd File deleted \ No newline at end of file
/trunk/VHDL/sdlc_serial_rx.vhd File deleted \ No newline at end of file
/trunk/VHDL/sdlc_serial_tx.vhd File deleted \ No newline at end of file
/trunk/VHDL/sdlc_serial_pkg.vhd File deleted \ No newline at end of file
/trunk/VHDL/sdlc_serial_rxfsm.vhd File deleted \ No newline at end of file
/trunk/VHDL/sdlc_serial_frame.vhd File deleted \ No newline at end of file
/trunk/VHDL/o8_sdlc_if.vhd
64,21 → 64,17
-- Revision History
-- Author Date Change
------------------ -------- ---------------------------------------------------
-- Seth Henry 04/16/20 Revision block added
-- Seth Henry 05/18/20 Added write qualification input
-- Seth Henry 11/01/20 Updated comments regarding SDLC support
-- Seth Henry 12/09/20 Created from merged sub-entities into flat file
 
library ieee;
use ieee.std_logic_1164.all;
use ieee.std_logic_unsigned.all;
use ieee.std_logic_arith.all;
use ieee.std_logic_misc.all;
 
library work;
use work.open8_pkg.all;
 
library work;
use work.sdlc_serial_pkg.all;
 
entity o8_sdlc_if is
generic(
Poly_Init : std_logic_vector(15 downto 0) := x"0000";
104,6 → 100,10
 
architecture behave of o8_sdlc_if is
 
-- convenient subtypes & constants
subtype CRC_TYPE is std_logic_vector(15 downto 0);
 
-- Bus interface
alias Clock is Open8_Bus.Clock;
alias Reset is Open8_Bus.Reset;
 
125,214 → 125,632
alias Reg_Lower_Addr is Open8_Bus.Address(0);
 
signal Reg_Addr : std_logic_vector(8 downto 1) := (others => '0');
signal Reg_Sel : std_logic := '0';
signal Reg_Wr_En_d : std_logic := '0';
signal Reg_Wr_En_q : std_logic := '0';
signal Reg_Clk_Sel : std_logic := '0';
signal Reg_TxS_Sel : std_logic := '0';
signal Reg_Sel : std_logic := '0';
signal Reg_Wr_En_d : std_logic := '0';
signal Reg_Wr_En_q : std_logic := '0';
signal TX_Ctl_Clk : std_logic := '0';
signal TX_Ctl_Len : std_logic := '0';
 
signal DP_B_Addr : std_logic_vector(8 downto 0) := (others => '0');
signal DP_B_Wr_Data : DATA_IN_TYPE := x"00";
signal DP_B_Wr_En : std_logic := '0';
signal DP_B_Rd_Data : DATA_IN_TYPE := x"00";
-- Dual-port memory
signal DP_Addr : std_logic_vector(8 downto 0);
signal DP_Wr_Data : DATA_TYPE;
signal DP_Wr_En : std_logic;
signal DP_Rd_Data : DATA_TYPE;
 
signal DP_Port0_Addr : DATA_IN_TYPE := x"00";
signal DP_Port0_RWn : std_logic := '0';
signal DP_Port0_WrData : DATA_IN_TYPE := x"00";
signal DP_Port0_RdData : DATA_IN_TYPE := x"00";
signal DP_Port0_Req : std_logic := '0';
signal DP_Port0_Ack : std_logic := '0';
alias DP_B_Addr is DP_Addr;
alias DP_B_Wr_Data is DP_Wr_Data;
alias DP_B_Wr_En is DP_Wr_En;
alias DP_B_Rd_Data is DP_Rd_Data;
 
signal DP_Port1_Addr : DATA_IN_TYPE := x"00";
signal DP_Port1_RWn : std_logic := '0';
signal DP_Port1_WrData : DATA_IN_TYPE := x"00";
signal DP_Port1_RdData : DATA_IN_TYPE := x"00";
signal DP_Port1_Req : std_logic := '0';
signal DP_Port1_Ack : std_logic := '0';
-- Internal definitions
constant SDLC_Flag : DATA_TYPE := x"7E";
 
signal BClk_RE : std_logic := '0';
signal BClk_FE : std_logic := '0';
signal BClk_Okay : std_logic := '0';
constant CK_REGISTER : DATA_TYPE := x"FE";
constant TX_REGISTER : DATA_TYPE := x"FF";
constant CS_REGISTER : DATA_TYPE := x"FE";
constant RX_REGISTER : DATA_TYPE := x"FF";
 
signal TX_Wr_En : std_logic := '0';
signal TX_Wr_Flag : std_logic := '0';
signal TX_Wr_Data : DATA_IN_TYPE := x"00";
signal TX_Req_Next : std_logic := '0';
constant TX_RESERVED_LOW : integer := 0;
constant TX_RESERVED_HIGH : integer := 254;
 
signal TX_CRC_Clr : std_logic := '0';
signal TX_CRC_En : std_logic := '0';
signal TX_CRC_Data : CRC_OUT_TYPE := x"0000";
signal TX_CRC_Valid : std_logic := '0';
constant FLAG_DONE : DATA_TYPE := x"FF";
 
signal RX_Valid : std_logic := '0';
signal RX_Flag : std_logic := '0';
signal RX_Data : DATA_IN_TYPE;
signal RX_Idle : std_logic := '0';
constant ERR_LENGTH : DATA_TYPE := x"00";
 
signal RX_Frame_Start : std_logic := '0';
signal RX_Frame_Stop : std_logic := '0';
signal RX_Frame_Valid : std_logic := '0';
signal RX_Frame_Data : DATA_IN_TYPE := x"00";
-- RAM Arbitration logic
type DP_ARB_STATES is (PAUSE, IDLE,
PORT0_AD, PORT0_WR, PORT0_RD0, PORT0_RD1,
PORT1_AD, PORT1_WR, PORT1_RD0, PORT1_RD1 );
signal DP_Arb_State : DP_ARB_STATES := IDLE;
signal DP_Last_Port : std_logic := '0';
 
signal RX_CRC_Valid : std_logic := '0';
signal RX_CRC_Data : CRC_OUT_TYPE := x"0000";
signal DP_Port0_Addr : DATA_TYPE := x"00";
signal DP_Port0_RWn : std_logic := '0';
signal DP_Port0_WrData : DATA_TYPE := x"00";
signal DP_Port0_RdData : DATA_TYPE := x"00";
signal DP_Port0_Req : std_logic := '0';
signal DP_Port0_Ack : std_logic := '0';
 
signal DP_Port1_Addr : DATA_TYPE := x"00";
signal DP_Port1_RWn : std_logic := '0';
signal DP_Port1_WrData : DATA_TYPE := x"00";
signal DP_Port1_RdData : DATA_TYPE := x"00";
signal DP_Port1_Req : std_logic := '0';
signal DP_Port1_Ack : std_logic := '0';
 
-- Clock generation
constant DLY_VAL : integer := integer(Clock_Frequency / (2.0 * BitClock_Frequency) );
constant DLY_WDT : integer := ceil_log2(DLY_VAL - 1);
constant DLY_VEC : std_logic_vector :=
conv_std_logic_vector( DLY_VAL - 1, DLY_WDT);
signal BClk_Cntr : std_logic_vector( DLY_WDT - 1 downto 0 ) := (others => '0');
 
signal BClk_Adv : std_logic := '0';
signal BClk_Accum : std_logic_vector(31 downto 0) := (others => '0');
signal BClk_Div : std_logic := '0';
signal BClk_Okay_SR : std_logic_vector(3 downto 0) := (others => '0');
 
 
signal BClk_SR : std_logic_vector(2 downto 0) := (others => '0');
 
constant CLK_RATIO_R : real := Clock_Frequency / (1.0 * BitClock_Frequency);
constant CLK_DEVIATION_5P : real := CLK_RATIO_R * 0.05;
constant CLK_RATIO_ADJ_R : real := CLK_RATIO_R + CLK_DEVIATION_5P;
constant CLK_RATIO_ADJ_I : integer := integer(CLK_RATIO_ADJ_R);
 
constant Threshold_bits : integer := ceil_log2(CLK_RATIO_ADJ_I);
constant THRESHOLD : std_logic_vector(Threshold_bits - 1 downto 0) :=
conv_std_logic_vector(CLK_RATIO_ADJ_I,Threshold_bits);
 
signal RE_Threshold_Ctr : std_logic_vector(Threshold_Bits - 1 downto 0) :=
(others => '0');
signal FE_Threshold_Ctr : std_logic_vector(Threshold_Bits - 1 downto 0) :=
(others => '0');
 
signal Ref_In_SR : std_logic_vector(2 downto 0) := (others => '0');
alias Ref_In_q1 is Ref_In_SR(1);
alias Ref_In_q2 is Ref_In_SR(2);
signal Ref_In_RE : std_logic := '0';
signal Ref_In_FE : std_logic := '0';
 
signal BClk_RE : std_logic := '0';
signal BClk_FE : std_logic := '0';
signal BClk_Okay : std_logic := '0';
 
-- Packet Transmit state logic
type TX_FSM_STATES is ( INIT_FLAG,
WR_CLOCK_STATE, WAIT_FOR_CLOCK,
WAIT_FOR_UPDATE,
RD_TX_REGISTER, TX_INIT,
TX_START_FLAG, TX_WAIT_START_FLAG,
TX_MESG_DATA, TX_ADV_ADDR, TX_WAIT_MESG_DATA,
TX_CRC_LB_WR, TX_CRC_LB_WAIT,
TX_CRC_UB_WR, TX_CRC_UB_WAIT,
TX_STOP_FLAG, TX_WAIT_STOP_FLAG, TX_SET_FLAG );
 
signal TX_FSM_State : TX_FSM_STATES := WR_CLOCK_STATE;
signal TX_Length : DATA_TYPE := x"00";
 
signal BClk_q1, BClk_CoS : std_logic := '0';
signal TX_Int_pend : std_logic := '0';
 
signal TX_Wr_En : std_logic := '0';
signal TX_Wr_Flag : std_logic := '0';
signal TX_Wr_Data : DATA_TYPE := x"00";
signal TX_Req_Next : std_logic := '0';
 
signal TX_CRC_Clr : std_logic := '0';
signal TX_CRC_En : std_logic := '0';
signal TX_CRC_Data : CRC_TYPE := x"0000";
signal TX_CRC_Valid : std_logic := '0';
 
alias TX_CRC_Data_LB is TX_CRC_Data(7 downto 0);
alias TX_CRC_Data_UB is TX_CRC_Data(15 downto 8);
 
signal TX_Arm : std_logic := '0';
signal TX_Flag : std_logic := '0';
signal TX_Buffer : std_logic_vector(8 downto 0) := (others => '0');
alias TX_Buffer_Flag is TX_Buffer(8);
alias TX_Buffer_Data is TX_Buffer(7 downto 0);
 
-- SDLC transmitter
type TX_STATES is (INIT, IDLE, XMIT, SPACE, TERM, LD_NEXT);
signal TX_State : TX_STATES := INIT;
 
signal TX_ShftReg : DATA_TYPE := (others => '0');
signal TX_Next : std_logic := '0';
signal TX_BitStuff : std_logic_vector(4 downto 0) := (others => '0');
signal TX_BitCntr : std_logic_vector(3 downto 0) := (others => '0');
alias TX_BitSel is TX_BitCntr(2 downto 0);
alias TX_Term is TX_BitCntr(3);
 
-- SDLC receiver
signal RX_LatchEn_SR : std_logic_vector(Clock_Offset downto 0) := (others => '0');
alias RX_LatchEn_M is RX_LatchEn_SR(Clock_Offset);
alias RX_LatchEn_S is BClk_RE;
signal RX_LatchEn : std_logic := '0';
 
signal RX_Serial_SR : std_logic_vector(1 downto 0) := (others => '0');
alias RX_Serial is RX_Serial_SR(1);
 
type RX_STATES is (INIT, IDLE, RCV_DATA, SKIP_ZERO, WRITE_DATA);
signal RX_State : RX_STATES := INIT;
signal RX_Buffer : DATA_TYPE := x"00";
signal RX_BitStuff_SR : std_logic_vector(4 downto 0) := (others => '0');
signal RX_BitCntr : std_logic_vector(3 downto 0) := (others => '0');
alias RX_BitSel is RX_BitCntr(2 downto 0);
alias RX_Term is RX_BitCntr(3);
 
signal RX_Flag_SR : DATA_TYPE := x"00";
 
signal RX_Idle_Cntr : std_logic_vector(2 downto 0) := (others => '0');
 
signal RX_Valid : std_logic := '0';
signal RX_Flag : std_logic := '0';
signal RX_Data : DATA_TYPE := x"00";
signal RX_Idle : std_logic := '0';
 
-- Packet detection logic
type PACKET_STATES is (IDLE, FRAME_START, FRAME_DATA, FRAME_STOP );
signal Pkt_State : PACKET_STATES := IDLE;
signal First_Byte : std_logic := '0';
 
signal RX_Frame_Start : std_logic := '0';
signal RX_Frame_Stop : std_logic := '0';
signal RX_Frame_Valid : std_logic := '0';
signal RX_Frame_Data : DATA_TYPE := x"00";
 
-- Receive data CRC calculation
signal RX_CRC_Valid : std_logic := '0';
signal RX_CRC_Data : CRC_TYPE := x"0000";
 
type CRC_HISTORY is array(0 to 2) of CRC_TYPE;
signal RX_CRC_Hist : CRC_HISTORY := (x"0000",x"0000",x"0000");
alias RX_CRC_Calc is RX_CRC_Hist(2);
 
signal RX_CRC_Rcvd : CRC_TYPE := x"0000";
alias RX_CRC_Rcvd_LB is RX_CRC_Rcvd(7 downto 0);
alias RX_CRC_Rcvd_UB is RX_CRC_Rcvd(15 downto 8);
 
-- Packet receive state logic
type RX_FSM_STATES is ( WAIT_FOR_CLOCK, WAIT_FOR_FLAG,
RX_MESG_DATA, RX_WR_DATA,
RX_CRC_LB_RD, RX_CRC_UB_RD,
RX_WR_CRC, RX_WR_COUNT );
 
signal RX_FSM_State : RX_FSM_STATES := WAIT_FOR_CLOCK;
 
signal RX_Length : DATA_TYPE := x"00";
 
begin
 
 
-- ***************************************************************************
-- * Open8 Bus Interface and Control Register Detection *
-- ***************************************************************************
 
-- This decode needs to happen immediately, to give the RAM a chance to
-- do the lookup before we have to set Rd_Data
Base_Addr_Match <= '1' when Base_Addr = CPU_Upper_Addr else '0';
Reg_Wr_En_d <= Base_Addr_Match and
Open8_Bus.Wr_En and
Write_Qual;
 
DP_A_Wr_En <= Base_Addr_Match and
Open8_Bus.Wr_En and
Write_Qual;
 
DP_A_Rd_En_d <= Base_Addr_Match and Open8_Bus.Rd_En;
 
CPU_IF_proc: process( Reset, Clock )
begin
if( Reset = Reset_Level )then
Reg_Addr <= (others => '0');
Reg_Wr_En_q <= '0';
TX_Ctl_Clk <= '0';
TX_Ctl_Len <= '0';
DP_A_Rd_En_q <= '0';
Rd_Data <= OPEN8_NULLBUS;
elsif( rising_edge(Clock) )then
Reg_Addr <= Reg_Upper_Addr;
Reg_Sel <= Reg_Lower_Addr;
Reg_Wr_En_q <= Reg_Wr_En_d;
 
TX_Ctl_Clk <= '0';
TX_Ctl_Len <= '0';
if( Reg_Addr = Reg_Sub_Addr )then
TX_Ctl_Clk <= Reg_Wr_En_q and not Reg_Sel;
TX_Ctl_Len <= Reg_Wr_En_q and Reg_Sel;
end if;
 
DP_A_Rd_En_q <= DP_A_Rd_En_d;
Rd_Data <= OPEN8_NULLBUS;
if( DP_A_Rd_En_q = '1' )then
Rd_Data <= DP_A_Rd_Data;
end if;
end if;
end process;
 
-- ***************************************************************************
-- * Shared Dual-Port Memory *
-- ***************************************************************************
 
U_RAM : entity work.sdlc_dp512b_ram
port map(
clock => Clock,
address_a => DP_A_Addr,
address_b => DP_B_Addr,
data_a => DP_A_Wr_Data,
data_b => DP_B_Wr_Data,
wren_a => DP_A_Wr_En,
wren_b => DP_B_Wr_En,
q_a => DP_A_Rd_Data,
q_b => DP_B_Rd_Data
);
 
-- ***************************************************************************
-- * Open8 Bus Interface and Control Register Detection *
-- * Memory Arbitration *
-- ***************************************************************************
 
-- This decode needs to happen immediately, to give the RAM a chance to
-- do the lookup before we have to set Rd_Data
Base_Addr_Match <= '1' when Base_Addr = CPU_Upper_Addr else '0';
Reg_Wr_En_d <= Base_Addr_Match and
Open8_Bus.Wr_En and
Write_Qual;
RAM_Arbitration_proc: process( Clock, Reset )
begin
if( Reset = Reset_Level )then
DP_Arb_State <= IDLE;
DP_Last_Port <= '0';
DP_Addr <= (others => '0');
DP_Wr_Data <= x"00";
DP_Wr_En <= '0';
DP_Port0_RdData <= x"00";
DP_Port0_Ack <= '0';
DP_Port1_RdData <= x"00";
DP_Port1_Ack <= '0';
elsif( rising_edge(Clock) )then
DP_Port0_Ack <= '0';
DP_Port1_Ack <= '0';
DP_Wr_En <= '0';
 
DP_A_Wr_En <= Base_Addr_Match and
Open8_Bus.Wr_En and
Write_Qual;
case( DP_Arb_State )is
when IDLE =>
if( DP_Port0_Req = '1' and (DP_Port1_Req = '0' or DP_Last_Port = '1') )then
DP_Arb_State <= PORT0_AD;
elsif( DP_Port1_Req = '1' and (DP_Port0_Req = '0' or DP_Last_Port = '0') )then
DP_Arb_State <= PORT1_AD;
end if;
 
DP_A_Rd_En_d <= Base_Addr_Match and Open8_Bus.Rd_En;
when PORT0_AD =>
DP_Last_Port <= '0';
DP_Addr <= '0' & DP_Port0_Addr;
DP_Wr_Data <= DP_Port0_WrData;
DP_Wr_En <= not DP_Port0_RWn;
if( DP_Port0_RWn = '1' )then
DP_Arb_State <= PORT0_RD0;
else
DP_Port0_Ack <= '1';
DP_Arb_State <= PORT0_WR;
end if;
 
CPU_IF_proc: process( Reset, Clock )
when PORT0_WR =>
DP_Arb_State <= IDLE;
 
when PORT0_RD0 =>
DP_Arb_State <= PORT0_RD1;
 
when PORT0_RD1 =>
DP_Port0_Ack <= '1';
DP_Port0_RdData <= DP_Rd_Data;
DP_Arb_State <= PAUSE;
 
when PORT1_AD =>
DP_Last_Port <= '1';
DP_Addr <= '1' & DP_Port1_Addr;
DP_Wr_Data <= DP_Port1_WrData;
DP_Wr_En <= not DP_Port1_RWn;
if( DP_Port0_RWn = '1' )then
DP_Arb_State <= PORT1_RD0;
else
DP_Port1_Ack <= '1';
DP_Arb_State <= PORT1_WR;
end if;
 
when PORT1_WR =>
DP_Arb_State <= IDLE;
 
when PORT1_RD0 =>
DP_Arb_State <= PORT1_RD1;
 
when PORT1_RD1 =>
DP_Port1_Ack <= '1';
DP_Port1_RdData <= DP_Rd_Data;
DP_Arb_State <= PAUSE;
 
when PAUSE =>
DP_Arb_State <= IDLE;
 
when others => null;
 
end case;
end if;
end process;
 
-- ****************************************************************************
-- * Bit clock generation *
-- ****************************************************************************
 
Clock_Master: if( Set_As_Master )generate
 
Clock_Gen_proc: process( Clock, Reset )
begin
if( Reset = Reset_Level )then
Reg_Addr <= (others => '0');
Reg_Wr_En_q <= '0';
Reg_Clk_Sel <= '0';
Reg_TxS_Sel <= '0';
DP_A_Rd_En_q <= '0';
Rd_Data <= OPEN8_NULLBUS;
BClk_Cntr <= DLY_VEC;
BClk_Adv <= '0';
BClk_Accum <= (others => '0');
BClk_Div <= '0';
BClk_Okay_SR <= (others => '0');
BClk_RE <= '0';
BClk_FE <= '0';
SDLC_MClk <= '0';
elsif( rising_edge( Clock ) )then
BClk_Cntr <= BClk_Cntr - 1;
BClk_Adv <= '0';
if( or_reduce(BClk_Cntr) = '0' )then
BClk_Cntr <= DLY_VEC;
BClk_Adv <= '1';
BClk_Okay_SR <= BClk_Okay_SR(2 downto 0) & '1';
end if;
BClk_Accum <= BClk_Accum + BClk_Adv;
BClk_Div <= BClk_Div xor BClk_Adv;
BClk_RE <= (not BClk_Div) and BClk_Adv;
BClk_FE <= BClk_Div and BClk_Adv;
SDLC_MClk <= BClk_Div;
end if;
end process;
 
BClk_Okay <= BClk_Okay_SR(3);
 
end generate;
 
Clock_Slave: if( not Set_As_Master )generate
 
Clock_Edge_proc: process( Clock, Reset )
begin
if( Reset = Reset_Level )then
BClk_SR <= (others => '0');
BClk_FE <= '0';
BClk_RE <= '0';
elsif( rising_edge(Clock) )then
Reg_Addr <= Reg_Upper_Addr;
Reg_Sel <= Reg_Lower_Addr;
Reg_Wr_En_q <= Reg_Wr_En_d;
BClk_SR <= BClk_SR(1 downto 0) & SDLC_SClk;
BClk_FE <= BClk_SR(2) and (not BClk_SR(1));
BClk_RE <= (not BClk_SR(2)) and BClk_SR(1);
end if;
end process;
 
Reg_Clk_Sel <= '0';
Reg_TxS_Sel <= '0';
if( Reg_Addr = Reg_Sub_Addr )then
Reg_Clk_Sel <= Reg_Wr_En_q and not Reg_Sel;
Reg_TxS_Sel <= Reg_Wr_En_q and Reg_Sel;
SDLC_MClk <= '0';
 
Clock_Detect_proc: process( Clock, Reset )
begin
if( Reset = Reset_Level )then
Ref_In_SR <= (others => '0');
Ref_In_RE <= '0';
Ref_In_FE <= '0';
RE_Threshold_Ctr <= (others => '0');
FE_Threshold_Ctr <= (others => '0');
BClk_Okay <= '0';
 
elsif( rising_edge(Clock) )then
Ref_In_SR <= Ref_In_SR(1 downto 0) & SDLC_SClk;
Ref_In_RE <= Ref_In_q1 and (not Ref_In_q2);
Ref_In_FE <= (not Ref_In_q1) and Ref_In_q2;
 
RE_Threshold_Ctr <= RE_Threshold_Ctr - 1;
if( Ref_In_RE = '1' )then
RE_Threshold_Ctr <= THRESHOLD;
elsif( or_reduce(RE_Threshold_Ctr) = '0' )then
RE_Threshold_Ctr <= (others => '0');
end if;
 
DP_A_Rd_En_q <= DP_A_Rd_En_d;
Rd_Data <= OPEN8_NULLBUS;
if( DP_A_Rd_En_q = '1' )then
Rd_Data <= DP_A_Rd_Data;
FE_Threshold_Ctr <= FE_Threshold_Ctr - 1;
if( Ref_In_FE = '1' )then
FE_Threshold_Ctr <= THRESHOLD;
elsif( or_reduce(FE_Threshold_Ctr) = '0' )then
FE_Threshold_Ctr <= (others => '0');
end if;
 
 
BClk_Okay <= or_reduce(RE_Threshold_Ctr) and
or_reduce(FE_Threshold_Ctr);
 
end if;
end process;
 
end generate;
 
-- ***************************************************************************
-- * Shared Dual-Port Memory *
-- * Serial Transmit Path *
-- ***************************************************************************
 
U_RAM : entity work.sdlc_dp512b_ram
port map(
clock => Clock,
address_a => DP_A_Addr,
address_b => DP_B_Addr,
data_a => DP_A_Wr_Data,
data_b => DP_B_Wr_Data,
wren_a => DP_A_Wr_En,
wren_b => DP_B_Wr_En,
q_a => DP_A_Rd_Data,
q_b => DP_B_Rd_Data
);
TX_Packet_RAM_proc: process( Reset, Clock )
begin
if( Reset = Reset_Level )then
TX_FSM_State <= INIT_FLAG;
 
-- ***************************************************************************
-- * Memory Arbitration *
-- ***************************************************************************
DP_Port0_Addr <= x"00";
DP_Port0_RWn <= '1';
DP_Port0_WrData <= x"00";
DP_Port0_Req <= '0';
 
U_ARB : entity work.sdlc_serial_arbfsm
generic map(
Reset_Level => Reset_Level
)
port map(
Clock => Clock,
Reset => Reset,
--
DP_Addr => DP_B_Addr,
DP_Wr_Data => DP_B_Wr_Data,
DP_Wr_En => DP_B_Wr_En,
DP_Rd_Data => DP_B_Rd_Data,
--
DP_Port0_Addr => DP_Port0_Addr,
DP_Port0_RWn => DP_Port0_RWn,
DP_Port0_WrData => DP_Port0_WrData,
DP_Port0_RdData => DP_Port0_RdData,
DP_Port0_Req => DP_Port0_Req,
DP_Port0_Ack => DP_Port0_Ack,
--
DP_Port1_Addr => DP_Port1_Addr,
DP_Port1_RWn => DP_Port1_RWn,
DP_Port1_WrData => DP_Port1_WrData,
DP_Port1_RdData => DP_Port1_RdData,
DP_Port1_Req => DP_Port1_Req,
DP_Port1_Ack => DP_Port1_Ack
);
TX_Length <= x"00";
 
-- ***************************************************************************
-- * Serial BitClock *
-- ***************************************************************************
TX_Wr_En <= '0';
TX_Wr_Flag <= '0';
TX_Wr_Data <= x"00";
 
U_BCLK : entity work.sdlc_serial_clk
generic map(
Set_As_Master => Set_As_Master,
BitClock_Freq => BitClock_Frequency,
Reset_Level => Reset_Level,
Sys_Freq => Clock_Frequency
)
port map(
Clock => Clock,
Reset => Reset,
--
BClk_In => SDLC_SClk,
BClk_Out => SDLC_MClk,
BClk_FE => BClk_FE,
BClk_RE => BClk_RE,
BClk_Okay => BClk_Okay
);
TX_CRC_Clr <= '0';
TX_CRC_En <= '0';
 
-- ***************************************************************************
-- * Serial Transmit Path *
-- ***************************************************************************
BClk_q1 <= '0';
BClk_CoS <= '0';
 
U_TXFSM: entity work.sdlc_serial_txfsm
generic map(
Reset_Level => Reset_Level
)
port map(
Clock => Clock,
Reset => Reset,
--
BClk_Okay => BClk_Okay,
--
Reg_Clk_Sel => Reg_Clk_Sel,
Reg_TxS_Sel => Reg_TxS_Sel,
--
DP_Port0_Addr => DP_Port0_Addr,
DP_Port0_RWn => DP_Port0_RWn,
DP_Port0_WrData => DP_Port0_WrData,
DP_Port0_RdData => DP_Port0_RdData,
DP_Port0_Req => DP_Port0_Req,
DP_Port0_Ack => DP_Port0_Ack,
--
TX_Wr_En => TX_Wr_En,
TX_Wr_Flag => TX_Wr_Flag,
TX_Wr_Data => TX_Wr_Data,
TX_Req_Next => TX_Req_Next,
--
TX_CRC_Clr => TX_CRC_Clr,
TX_CRC_En => TX_CRC_En,
TX_CRC_Data => TX_CRC_Data,
TX_CRC_Valid => TX_CRC_Valid,
--
TX_Interrupt => TX_Interrupt
);
TX_Int_pend <= '0';
TX_Interrupt <= '0';
 
elsif( rising_edge(Clock) )then
 
DP_Port0_RWn <= '1';
DP_Port0_WrData <= x"00";
DP_Port0_Req <= '0';
 
TX_Wr_En <= '0';
TX_Wr_Flag <= '0';
TX_Wr_Data <= x"00";
 
TX_CRC_Clr <= '0';
TX_CRC_En <= '0';
 
BClk_q1 <= BClk_Okay;
BClk_CoS <= BClk_q1 xor BClk_Okay;
 
TX_Interrupt <= '0';
 
case( TX_FSM_State )is
 
when INIT_FLAG =>
DP_Port0_Addr <= TX_REGISTER;
DP_Port0_Req <= '1';
DP_Port0_WrData <= FLAG_DONE;
DP_Port0_RWn <= '0';
if( DP_Port0_Ack = '1' )then
DP_Port0_Req <= '0';
TX_FSM_State <= WR_CLOCK_STATE;
end if;
 
when WAIT_FOR_UPDATE =>
if( TX_Ctl_Clk = '1' )then
TX_FSM_State <= WR_CLOCK_STATE;
end if;
if( TX_Ctl_Len = '1' )then
TX_FSM_State <= RD_TX_REGISTER;
end if;
 
when WR_CLOCK_STATE =>
DP_Port0_Addr <= CK_REGISTER;
DP_Port0_Req <= '1';
DP_Port0_WrData <= (others => BClk_Okay);
DP_Port0_RWn <= '0';
if( DP_Port0_Ack = '1' )then
TX_Interrupt <= TX_Int_pend;
TX_Int_pend <= '0';
DP_Port0_Req <= '0';
TX_FSM_State <= WAIT_FOR_CLOCK;
end if;
 
when WAIT_FOR_CLOCK =>
if( BClk_Okay = '1' )then
TX_FSM_State <= WAIT_FOR_UPDATE;
end if;
 
when RD_TX_REGISTER =>
DP_Port0_Addr <= TX_REGISTER;
DP_Port0_Req <= '1';
if( DP_Port0_Ack = '1' )then
DP_Port0_Req <= '0';
TX_Length <= DP_Port0_RdData;
TX_FSM_State <= TX_INIT;
end if;
 
when TX_INIT =>
TX_FSM_State <= WAIT_FOR_UPDATE;
if( TX_Length > TX_RESERVED_LOW and
TX_Length < TX_RESERVED_HIGH )then
TX_CRC_Clr <= '1';
TX_FSM_State <= TX_START_FLAG;
end if;
 
when TX_START_FLAG =>
TX_Wr_En <= '1';
TX_Wr_Flag <= '1';
TX_Wr_Data <= SDLC_FLAG;
TX_FSM_State <= TX_WAIT_START_FLAG;
 
when TX_WAIT_START_FLAG =>
if( TX_Req_Next = '1' )then
DP_Port0_Addr <= x"00";
TX_FSM_State <= TX_ADV_ADDR;
end if;
 
when TX_ADV_ADDR =>
DP_Port0_Req <= '1';
if( DP_Port0_Ack = '1' )then
DP_Port0_Req <= '0';
DP_Port0_Addr <= DP_Port0_Addr + 1;
TX_Length <= TX_Length - 1;
TX_FSM_State <= TX_MESG_DATA;
end if;
 
when TX_MESG_DATA =>
TX_Wr_En <= '1';
TX_Wr_Data <= DP_Port0_RdData;
TX_CRC_En <= '1';
TX_FSM_State <= TX_WAIT_MESG_DATA;
 
when TX_WAIT_MESG_DATA =>
if( TX_Req_Next = '1' )then
TX_FSM_State <= TX_ADV_ADDR;
if( TX_Length = 0 )then
TX_FSM_State <= TX_CRC_LB_WR;
end if;
end if;
 
when TX_CRC_LB_WR =>
TX_Wr_En <= '1';
TX_Wr_Data <= TX_CRC_Data_LB;
TX_FSM_State <= TX_CRC_LB_WAIT;
 
when TX_CRC_LB_WAIT =>
if( TX_Req_Next = '1' )then
TX_FSM_State <= TX_CRC_UB_WR;
end if;
 
when TX_CRC_UB_WR =>
TX_Wr_En <= '1';
TX_Wr_Data <= TX_CRC_Data_UB;
TX_FSM_State <= TX_CRC_UB_WAIT;
 
when TX_CRC_UB_WAIT =>
if( TX_Req_Next = '1' )then
TX_FSM_State <= TX_STOP_FLAG;
end if;
 
when TX_STOP_FLAG =>
TX_Wr_En <= '1';
TX_Wr_Flag <= '1';
TX_Wr_Data <= SDLC_FLAG;
TX_FSM_State <= TX_WAIT_STOP_FLAG;
 
when TX_WAIT_STOP_FLAG =>
if( TX_Req_Next = '1' )then
TX_FSM_State <= TX_SET_FLAG;
end if;
 
when TX_SET_FLAG =>
DP_Port0_Addr <= TX_REGISTER;
DP_Port0_Req <= '1';
DP_Port0_WrData <= FLAG_DONE;
DP_Port0_RWn <= '0';
if( DP_Port0_Ack = '1' )then
DP_Port0_Req <= '0';
TX_FSM_State <= WAIT_FOR_UPDATE;
end if;
 
when others => null;
end case;
 
if( BClk_CoS = '1' )then
TX_Int_pend <= '1';
TX_FSM_State <= WR_CLOCK_STATE;
end if;
 
end if;
end process;
 
U_TX_CRC : entity work.sdlc_crc16_ccitt
generic map(
Poly_Init => Poly_Init,
350,70 → 768,293
CRC16_Out => TX_CRC_Data
);
 
U_TX_SER : entity work.sdlc_serial_tx
generic map(
Reset_Level => Reset_Level
)
port map(
Clock => Clock,
Reset => Reset,
--
BClk_FE => BClk_FE,
BClk_RE => BClk_RE,
BClk_Okay => BClk_Okay,
--
TX_En => TX_Wr_En,
TX_FSS_Flag => TX_Wr_Flag,
TX_Data => TX_Wr_Data,
TX_Req_Next => TX_Req_Next,
--
Serial_Out => SDLC_Out
);
TX_Serial_proc: process( Clock, Reset )
begin
if( Reset = Reset_Level )then
TX_State <= IDLE;
SDLC_Out <= '1';
TX_Arm <= '0';
TX_Buffer <= (others => '0');
TX_Flag <= '0';
TX_ShftReg <= (others => '0');
TX_BitStuff <= (others => '0');
TX_BitCntr <= (others => '1');
TX_Req_Next <= '0';
elsif( rising_edge(Clock) )then
 
if( TX_Wr_En = '1' and TX_Arm = '0')then
TX_Arm <= '1';
TX_Buffer_Flag <= TX_Wr_Flag;
TX_Buffer_Data <= TX_Wr_Data;
end if;
 
TX_Req_Next <= '0';
 
case( TX_State )is
when INIT =>
SDLC_Out <= '1';
TX_State <= IDLE;
 
when IDLE =>
SDLC_Out <= '1';
if( TX_Arm = '1' and BClk_FE = '1' )then
TX_Arm <= '0';
TX_BitCntr <= (others => '0');
TX_BitStuff <= (others => '0');
TX_Flag <= TX_Buffer_Flag;
TX_ShftReg <= TX_Buffer_Data;
TX_Req_Next <= '1';
TX_State <= XMIT;
end if;
 
when XMIT =>
SDLC_Out <= TX_ShftReg(conv_integer(TX_BitSel));
TX_BitCntr <= TX_BitCntr + BClk_FE;
if( BClk_RE = '1' )then
TX_BitStuff <= TX_BitStuff(3 downto 0) &
TX_ShftReg(conv_integer(TX_BitSel));
end if;
if( BClk_FE = '1' )then
if( TX_BitCntr >= 7 )then
TX_State <= TERM;
elsif( and_reduce(TX_BitStuff) = '1' and TX_Flag = '0' )then
TX_BitStuff <= (others => '0');
TX_State <= SPACE;
else
TX_BitCntr <= TX_BitCntr + 1;
end if;
end if;
 
when SPACE =>
SDLC_Out <= '0';
if( BClk_FE = '1' )then
TX_State <= XMIT;
end if;
 
when TERM =>
if( TX_Arm = '1' )then
TX_State <= LD_NEXT;
else
TX_State <= IDLE;
end if;
 
when LD_NEXT =>
TX_Arm <= '0';
TX_BitCntr <= (others => '0');
TX_Flag <= TX_Buffer_Flag;
TX_ShftReg <= TX_Buffer_Data;
TX_Req_Next <= '1';
TX_State <= XMIT;
if( and_reduce(TX_BitStuff) = '1' and TX_Flag = '0' )then
TX_BitStuff <= (others => '0');
TX_State <= SPACE;
end if;
 
when others => null;
end case;
 
if( BClk_Okay = '0' )then
TX_State <= INIT;
end if;
 
end if;
end process;
 
-- ***************************************************************************
-- * Serial Receive Path *
-- ***************************************************************************
 
U_RX_SER : entity work.sdlc_serial_rx
generic map(
Set_As_Master => Set_As_Master,
Clock_Offset => Clock_Offset,
Reset_Level => Reset_Level
)
port map(
Clock => Clock,
Reset => Reset,
--
BClk_RE => BClk_RE,
BClk_Okay => BClk_Okay,
--
Serial_In => SDLC_In,
--
RX_Valid => RX_Valid,
RX_Flag => RX_Flag,
RX_Data => RX_Data,
RX_Idle => RX_Idle
);
IF_Is_Master: if( Set_As_Master )generate
 
U_RX_PKT : entity work.sdlc_serial_frame
generic map(
Reset_Level => Reset_Level
)
port map(
Clock => Clock,
Reset => Reset,
--
RX_Valid => RX_Valid,
RX_Flag => RX_Flag,
RX_Data => RX_Data,
RX_Idle => RX_Idle,
--
RX_Frame_Start => RX_Frame_Start,
RX_Frame_Stop => RX_Frame_Stop,
RX_Frame_Valid => RX_Frame_Valid,
RX_Frame_Data => RX_Frame_Data
);
Input_proc: process( Clock, Reset )
begin
if( Reset = Reset_Level )then
RX_LatchEn_SR <= (others => '0');
RX_Serial_SR <= (others => '0');
elsif( rising_edge(Clock) )then
RX_LatchEn_SR <= RX_LatchEn_SR(Clock_Offset - 1 downto 0) & BClk_RE;
RX_Serial_SR <= RX_Serial_SR(0) & SDLC_In;
end if;
end process;
 
RX_LatchEn <= RX_LatchEn_M;
 
end generate;
 
IF_Is_Slave: if( not Set_As_Master )generate
 
Input_proc: process( Clock, Reset )
begin
if( Reset = Reset_Level )then
RX_Serial_SR <= (others => '0');
elsif( rising_edge(Clock) )then
RX_Serial_SR <= RX_Serial_SR(0) & SDLC_In;
end if;
end process;
 
RX_LatchEn <= RX_LatchEn_S;
 
end generate;
 
RX_Serial_proc: process( Clock, Reset )
begin
if( Reset = Reset_Level )then
 
RX_BitStuff_SR <= (others => '0');
RX_Flag_SR <= (others => '0');
RX_Idle_Cntr <= (others => '0');
 
RX_State <= IDLE;
RX_Idle <= '0';
 
RX_Buffer <= (others => '0');
RX_BitCntr <= (others => '0');
 
RX_Valid <= '0';
RX_Flag <= '0';
RX_Data <= (others => '0');
 
elsif( rising_edge(Clock) )then
 
if( RX_LatchEn = '1' )then
RX_Flag_SR <= RX_Flag_SR(6 downto 0) & RX_Serial;
if( RX_State = IDLE )then
RX_Flag_SR <= (others => '0');
end if;
 
RX_Idle_Cntr <= RX_Idle_Cntr + RX_Serial;
if( and_reduce(RX_Idle_Cntr) = '1' )then
RX_Idle_Cntr <= "111";
end if;
end if;
 
if( RX_Serial = '0' )then
RX_Idle_Cntr <= (others => '0');
end if;
 
RX_Valid <= '0';
RX_Flag <= '0';
RX_Idle <= '0';
 
case( RX_State )is
 
when INIT =>
RX_Idle <= '1';
RX_State <= IDLE;
 
when IDLE =>
RX_Idle <= '1';
RX_BitCntr <= (others => '0');
RX_BitStuff_SR <= (others => '0');
if( RX_Serial = '0' )then
RX_State <= RCV_DATA;
end if;
 
when RCV_DATA =>
if( RX_Term = '1' )then
RX_State <= WRITE_DATA;
end if;
if( RX_LatchEn = '1' )then
RX_Buffer(conv_integer(RX_BitSel)) <= RX_Serial;
RX_BitStuff_SR <= RX_BitStuff_SR(3 downto 0) & RX_Serial;
RX_BitCntr <= RX_BitCntr + 1;
 
if( and_reduce(RX_BitStuff_SR) = '1' )then
RX_BitStuff_SR <= (others => '0');
if( RX_Serial = '0' )then
RX_BitCntr <= RX_BitCntr;
RX_State <= SKIP_ZERO;
end if;
end if;
end if;
 
when SKIP_ZERO =>
RX_State <= RCV_DATA;
 
when WRITE_DATA =>
RX_BitCntr <= (others => '0');
RX_Valid <= '1';
RX_Data <= RX_Buffer;
if( RX_Flag_SR = SDLC_Flag )then
RX_Flag <= '1';
end if;
RX_State <= RCV_DATA;
 
when others => null;
end case;
 
-- If we just shifted in the flag character, and the bit counter isn't
-- 0x0, then our bit counter is out of alignment. Reset it to zero so
-- that the next word is clocked in correctly.
if( RX_Flag_SR = SDLC_Flag and RX_BitCntr > 0 )then
RX_BitCntr <= (others => '0');
end if;
 
-- If the serial line goes idle (In the marking state for more than 7
-- bit times), and the FSM isn't already in IDLE, force it to IDLE.
if( and_reduce(RX_Idle_Cntr) = '1' and RX_State /= IDLE )then
RX_State <= IDLE;
end if;
 
-- If the bit clock is no longer valid, soft-reset to the INIT state.
if( BClk_Okay = '0' )then
RX_State <= INIT;
end if;
 
end if;
end process;
 
Packet_Marker_proc: process( Clock, Reset )
begin
if( Reset = Reset_Level )then
Pkt_State <= IDLE;
First_Byte <= '0';
RX_Frame_Start <= '0';
RX_Frame_Stop <= '0';
RX_Frame_Valid <= '0';
RX_Frame_Data <= x"00";
elsif( rising_edge(Clock) )then
RX_Frame_Start <= '0';
RX_Frame_Stop <= '0';
RX_Frame_Valid <= '0';
 
case( Pkt_State )is
when IDLE =>
if( RX_Valid = '1' and RX_Flag = '1' )then
Pkt_State <= FRAME_START;
end if;
 
when FRAME_START =>
if( RX_Valid = '1' and RX_Flag = '0' )then
RX_Frame_Start <= '1';
First_Byte <= '1';
Pkt_State <= FRAME_DATA;
end if;
 
when FRAME_DATA =>
First_Byte <= '0';
if( (RX_Valid = '1' and RX_Flag = '0') or
First_Byte = '1' )then
RX_Frame_Valid <= '1';
RX_Frame_Data <= RX_Data;
elsif( RX_Valid = '1' and RX_Flag = '1' )then
Pkt_State <= FRAME_STOP;
end if;
 
when FRAME_STOP =>
RX_Frame_Stop <= not RX_Idle;
Pkt_State <= IDLE;
 
when others => null;
end case;
 
if( RX_Idle = '1' and Pkt_State /= IDLE )then
Pkt_State <= FRAME_STOP;
end if;
 
end if;
end process;
 
U_RX_CRC : entity work.sdlc_crc16_ccitt
generic map(
Poly_Init => Poly_Init,
431,32 → 1072,131
CRC16_Out => RX_CRC_Data
);
 
U_RX_FSM : entity work.sdlc_serial_rxfsm
generic map(
Reset_Level => Reset_Level
)
port map(
Clock => Clock,
Reset => Reset,
--
BClk_Okay => BClk_Okay,
--
DP_Port1_Addr => DP_Port1_Addr,
DP_Port1_RWn => DP_Port1_RWn,
DP_Port1_WrData => DP_Port1_WrData,
DP_Port1_RdData => DP_Port1_RdData,
DP_Port1_Req => DP_Port1_Req,
DP_Port1_Ack => DP_Port1_Ack,
--
RX_CRC_Valid => RX_CRC_Valid,
RX_CRC_Data => RX_CRC_Data,
--
RX_Frame_Start => RX_Frame_Start,
RX_Frame_Stop => RX_Frame_Stop,
RX_Frame_Valid => RX_Frame_Valid,
RX_Frame_Data => RX_Frame_Data,
--
RX_Interrupt => RX_Interrupt
);
CRC_History_proc: process( Clock, Reset )
begin
if( Reset = Reset_Level )then
RX_CRC_Hist(0) <= x"0000";
RX_CRC_Hist(1) <= x"0000";
RX_CRC_Hist(2) <= x"0000";
elsif( rising_edge(Clock) )then
if( RX_CRC_Valid = '1' )then
RX_CRC_Hist(2) <= RX_CRC_Hist(1);
RX_CRC_Hist(1) <= RX_CRC_Hist(0);
RX_CRC_Hist(0) <= RX_CRC_Data;
end if;
end if;
end process;
 
RX_Packet_RAM_proc: process( Reset, Clock )
begin
if( Reset = Reset_Level )then
RX_FSM_State <= WAIT_FOR_CLOCK;
 
DP_Port1_Addr <= x"00";
DP_Port1_RWn <= '1';
DP_Port1_WrData <= x"00";
DP_Port1_Req <= '0';
 
RX_Length <= x"00";
 
RX_CRC_Rcvd <= x"0000";
 
RX_Interrupt <= '0';
 
elsif( rising_edge(Clock) )then
 
DP_Port1_Addr <= x"00";
DP_Port1_RWn <= '1';
DP_Port1_WrData <= x"00";
DP_Port1_Req <= '0';
 
RX_Interrupt <= '0';
 
case( RX_FSM_State )is
 
when WAIT_FOR_CLOCK =>
RX_FSM_State <= WAIT_FOR_FLAG;
 
when WAIT_FOR_FLAG =>
if( RX_Frame_Start = '1' )then
RX_Length <= x"00";
RX_FSM_State <= RX_MESG_DATA;
end if;
 
when RX_MESG_DATA =>
if( RX_Frame_Stop = '1' )then
RX_Length <= RX_Length - 1;
RX_FSM_State <= RX_CRC_UB_RD;
elsif( RX_Frame_Valid = '1' )then
RX_FSM_State <= RX_WR_DATA;
if( RX_Length > 254 )then
RX_Length <= ERR_LENGTH;
RX_FSM_State <= RX_WR_COUNT;
end if;
end if;
 
when RX_WR_DATA =>
RX_Length <= RX_Length + DP_Port1_Ack;
DP_Port1_Addr <= RX_Length;
DP_Port1_WrData <= RX_Frame_Data;
DP_Port1_RWn <= '0';
DP_Port1_Req <= '1';
if( DP_Port1_Ack = '1' )then
DP_Port1_Req <= '0';
RX_FSM_State <= RX_MESG_DATA;
end if;
 
when RX_CRC_UB_RD =>
RX_Length <= RX_Length - DP_Port1_Ack;
DP_Port1_Addr <= RX_Length;
DP_Port1_Req <= '1';
if( DP_Port1_Ack = '1' )then
DP_Port1_Req <= '0';
RX_CRC_Rcvd_UB <= DP_Port1_RdData;
RX_FSM_State <= RX_CRC_LB_RD;
end if;
 
when RX_CRC_LB_RD =>
DP_Port1_Addr <= RX_Length;
DP_Port1_Req <= '1';
if( DP_Port1_Ack = '1' )then
DP_Port1_Req <= '0';
RX_CRC_Rcvd_LB <= DP_Port1_RdData;
RX_FSM_State <= RX_WR_CRC;
end if;
 
when RX_WR_CRC =>
DP_Port1_Addr <= CS_REGISTER;
DP_Port1_WrData <= x"FF";
if( RX_CRC_Rcvd /= RX_CRC_Calc )then
DP_Port1_WrData <= x"00";
end if;
DP_Port1_RWn <= '0';
DP_Port1_Req <= '1';
if( DP_Port1_Ack = '1' )then
DP_Port1_Req <= '0';
RX_FSM_State <= RX_WR_COUNT;
end if;
 
when RX_WR_COUNT =>
DP_Port1_Addr <= RX_REGISTER;
DP_Port1_WrData <= RX_Length;
DP_Port1_RWn <= '0';
DP_Port1_Req <= '1';
if( DP_Port1_Ack = '1' )then
DP_Port1_Req <= '0';
RX_Interrupt <= '1';
RX_FSM_State <= WAIT_FOR_FLAG;
end if;
 
when others => null;
end case;
 
if( BClk_Okay = '0' )then
RX_FSM_State <= WAIT_FOR_FLAG;
end if;
 
end if;
end process;
 
end architecture;
/trunk/VHDL/sdlc_crc16_ccitt.vhd
1,122 → 1,119
-- Copyright (c)2020 Jeremy Seth Henry
-- All rights reserved.
--
-- Redistribution and use in source and binary forms, with or without
-- modification, are permitted provided that the following conditions are met:
-- * Redistributions of source code must retain the above copyright
-- notice, this list of conditions and the following disclaimer.
-- * Redistributions in binary form must reproduce the above copyright
-- notice, this list of conditions and the following disclaimer in the
-- documentation and/or other materials provided with the distribution,
-- where applicable (as part of a user interface, debugging port, etc.)
--
-- THIS SOFTWARE IS PROVIDED BY JEREMY SETH HENRY ``AS IS'' AND ANY
-- EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
-- WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
-- DISCLAIMED. IN NO EVENT SHALL JEREMY SETH HENRY BE LIABLE FOR ANY
-- DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
-- (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
-- LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
-- ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-- (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
-- THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
--
-- VHDL Units : crc16_ccitt
-- Description: Implements the 16-bit CCITT CRC on byte-wide data. Logic
-- equations were taken from Intel/Altera app note AN049.
--
-- Revision History
-- Author Date Change
------------------ -------- ---------------------------------------------------
-- Seth Henry 04/14/20 Code cleanup and revision section added
 
library ieee;
use ieee.std_logic_1164.all;
 
library work;
use work.sdlc_serial_pkg.all;
 
entity sdlc_crc16_ccitt is
generic(
Poly_Init : std_logic_vector(15 downto 0) := x"0000";
Reset_Level : std_logic := '1'
);
port(
Clock : in std_logic;
Reset : in std_logic;
--
Clear : in std_logic;
Wr_En : in std_logic;
Wr_Data : in DATA_IN_TYPE;
--
CRC16_Valid : out std_logic;
CRC16_Out : out CRC_OUT_TYPE
);
end entity;
 
architecture behave of sdlc_crc16_ccitt is
 
signal Calc_En : std_logic := '0';
signal Buffer_En : std_logic := '0';
signal Data : DATA_IN_TYPE := x"00";
signal Exr : DATA_IN_TYPE := x"00";
signal Reg : CRC_OUT_TYPE := x"0000";
 
begin
 
Exr(0) <= Reg(0) xor Data(0);
Exr(1) <= Reg(1) xor Data(1);
Exr(2) <= Reg(2) xor Data(2);
Exr(3) <= Reg(3) xor Data(3);
Exr(4) <= Reg(4) xor Data(4);
Exr(5) <= Reg(5) xor Data(5);
Exr(6) <= Reg(6) xor Data(6);
Exr(7) <= Reg(7) xor Data(7);
 
CRC16_Calc: process( Clock, Reset )
begin
if( Reset = Reset_Level )then
Calc_En <= '0';
Buffer_En <= '0';
Data <= x"00";
Reg <= Poly_Init;
CRC16_Out <= x"0000";
CRC16_Valid <= '0';
elsif( rising_edge(Clock) )then
Calc_En <= Wr_En;
if( Wr_En = '1' )then
Data <= Wr_Data;
end if;
 
if( Calc_En = '1' )then
Reg(0) <= Reg(8) xor Exr(4) xor Exr(0);
Reg(1) <= Reg(9) xor Exr(5) xor Exr(1);
Reg(2) <= Reg(10) xor Exr(6) xor Exr(2);
Reg(3) <= Reg(11) xor Exr(0) xor Exr(7) xor Exr(3);
Reg(4) <= Reg(12) xor Exr(1) ;
Reg(5) <= Reg(13) xor Exr(2) ;
Reg(6) <= Reg(14) xor Exr(3) ;
Reg(7) <= Reg(15) xor Exr(4) xor Exr(0);
Reg(8) <= Exr(0) xor Exr(5) xor Exr(1);
Reg(9) <= Exr(1) xor Exr(6) xor Exr(2);
Reg(10) <= Exr(2) xor Exr(7) xor Exr(3);
Reg(11) <= Exr(3) ;
Reg(12) <= Exr(4) xor Exr(0);
Reg(13) <= Exr(5) xor Exr(1);
Reg(14) <= Exr(6) xor Exr(2);
Reg(15) <= Exr(7) xor Exr(3);
end if;
 
if( Clear = '1' )then
Reg <= Poly_Init;
end if;
 
Buffer_En <= Calc_En;
if( Buffer_En = '1' )then
CRC16_Out <= Reg xor x"FFFF";
end if;
CRC16_Valid <= Buffer_En;
end if;
end process;
 
end architecture;
-- Copyright (c)2020 Jeremy Seth Henry
-- All rights reserved.
--
-- Redistribution and use in source and binary forms, with or without
-- modification, are permitted provided that the following conditions are met:
-- * Redistributions of source code must retain the above copyright
-- notice, this list of conditions and the following disclaimer.
-- * Redistributions in binary form must reproduce the above copyright
-- notice, this list of conditions and the following disclaimer in the
-- documentation and/or other materials provided with the distribution,
-- where applicable (as part of a user interface, debugging port, etc.)
--
-- THIS SOFTWARE IS PROVIDED BY JEREMY SETH HENRY ``AS IS'' AND ANY
-- EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
-- WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
-- DISCLAIMED. IN NO EVENT SHALL JEREMY SETH HENRY BE LIABLE FOR ANY
-- DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
-- (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
-- LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
-- ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-- (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
-- THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
--
-- VHDL Units : crc16_ccitt
-- Description: Implements the 16-bit CCITT CRC on byte-wide data. Logic
-- equations were taken from Intel/Altera app note AN049.
--
-- Revision History
-- Author Date Change
------------------ -------- ---------------------------------------------------
-- Seth Henry 12/09/20 Created from original version
 
library ieee;
use ieee.std_logic_1164.all;
 
entity sdlc_crc16_ccitt is
generic(
Poly_Init : std_logic_vector(15 downto 0) := x"0000";
Reset_Level : std_logic := '1'
);
port(
Clock : in std_logic;
Reset : in std_logic;
--
Clear : in std_logic;
Wr_En : in std_logic;
Wr_Data : in std_logic_vector(7 downto 0);
--
CRC16_Valid : out std_logic;
CRC16_Out : out std_logic_vector(15 downto 0)
);
end entity;
 
architecture behave of sdlc_crc16_ccitt is
 
signal Calc_En : std_logic := '0';
signal Buffer_En : std_logic := '0';
signal Data : std_logic_vector(7 downto 0) := x"00";
signal Exr : std_logic_vector(7 downto 0) := x"00";
signal Reg : std_logic_vector(15 downto 0) := x"0000";
 
begin
 
Exr(0) <= Reg(0) xor Data(0);
Exr(1) <= Reg(1) xor Data(1);
Exr(2) <= Reg(2) xor Data(2);
Exr(3) <= Reg(3) xor Data(3);
Exr(4) <= Reg(4) xor Data(4);
Exr(5) <= Reg(5) xor Data(5);
Exr(6) <= Reg(6) xor Data(6);
Exr(7) <= Reg(7) xor Data(7);
 
CRC16_Calc: process( Clock, Reset )
begin
if( Reset = Reset_Level )then
Calc_En <= '0';
Buffer_En <= '0';
Data <= x"00";
Reg <= Poly_Init;
CRC16_Out <= x"0000";
CRC16_Valid <= '0';
elsif( rising_edge(Clock) )then
Calc_En <= Wr_En;
if( Wr_En = '1' )then
Data <= Wr_Data;
end if;
 
if( Calc_En = '1' )then
Reg(0) <= Reg(8) xor Exr(4) xor Exr(0);
Reg(1) <= Reg(9) xor Exr(5) xor Exr(1);
Reg(2) <= Reg(10) xor Exr(6) xor Exr(2);
Reg(3) <= Reg(11) xor Exr(0) xor Exr(7) xor Exr(3);
Reg(4) <= Reg(12) xor Exr(1) ;
Reg(5) <= Reg(13) xor Exr(2) ;
Reg(6) <= Reg(14) xor Exr(3) ;
Reg(7) <= Reg(15) xor Exr(4) xor Exr(0);
Reg(8) <= Exr(0) xor Exr(5) xor Exr(1);
Reg(9) <= Exr(1) xor Exr(6) xor Exr(2);
Reg(10) <= Exr(2) xor Exr(7) xor Exr(3);
Reg(11) <= Exr(3) ;
Reg(12) <= Exr(4) xor Exr(0);
Reg(13) <= Exr(5) xor Exr(1);
Reg(14) <= Exr(6) xor Exr(2);
Reg(15) <= Exr(7) xor Exr(3);
end if;
 
if( Clear = '1' )then
Reg <= Poly_Init;
end if;
 
Buffer_En <= Calc_En;
if( Buffer_En = '1' )then
CRC16_Out <= Reg xor x"FFFF";
end if;
CRC16_Valid <= Buffer_En;
end if;
end process;
 
end architecture;

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