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uPD77c25 (core fully operational, no firmware download)

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This commit is contained in:
ikari 2011-06-07 14:05:49 +02:00
parent 3539cae325
commit a19ce8c07f
1 changed files with 301 additions and 210 deletions
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verilog/sd2snes/upd77c25.v
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@ -1,21 +1,19 @@
`timescale 1ns / 1ps
//////////////////////////////////////////////////////////////////////////////////
// Company:
// Engineer:
// Engineer: ikari
//
// Create Date: 17:09:03 01/16/2011
// Design Name:
// Module Name: upd77c25
// Project Name:
// Target Devices:
// Tool versions:
// Description:
// Project Name: sd2snes
// Target Devices: xc3s400
// Tool versions: ISE 13.1
// Description: NEC uPD77C25 core (for SNES DSP1-4)
//
// Dependencies:
//
// Revision:
// Revision 0.01 - File Created
// Additional Comments:
// Revision 0.1 - core fully operational, no firmware download
//
//////////////////////////////////////////////////////////////////////////////////
module upd77c25(
@ -34,9 +32,19 @@ module upd77c25(
input DAT_WR,
input [15:0] DAT_DI,
input [9:0] DAT_WR_ADDR
input [9:0] DAT_WR_ADDR,
// debug
output [15:0] DR,
output [15:0] SR,
output [10:0] PC,
output [15:0] A,
output [15:0] B,
output [5:0] FL_A,
output [5:0] FL_B
);
parameter I_OP = 2'b00;
parameter I_RT = 2'b01;
parameter I_JP = 2'b10;
@ -46,20 +54,16 @@ parameter SR_RQM = 15;
parameter SR_DRS = 12;
parameter SR_DRC = 10;
parameter FL_OV0 = 0;
parameter FL_OV1 = 1;
parameter FL_Z = 2;
parameter FL_C = 3;
parameter FL_S0 = 4;
parameter FL_S1 = 5;
reg [5:0] flags_r[1:0];
reg [5:0] flags_in;
reg [5:0] flags_out;
reg [1:0] flags_ov0;
reg [1:0] flags_ov1;
reg [1:0] flags_z;
reg [1:0] flags_c;
reg [1:0] flags_s0;
reg [1:0] flags_s1;
reg [10:0] pc; // program counter
reg [1:0] insn_state; // execute clock state
reg [2:0] insn_state; // execute state
reg [3:0] regs_dph;
reg [3:0] regs_dpl;
@ -74,25 +78,22 @@ wire [10:0] pgm_addra;
wire [23:0] pgm_dina;
wire [23:0] pgm_doutb;
upd77c25_pgmrom pgmrom (
pgmrom pgmrom (
.clka(CLK),
.wea(PGM_WR), // Bus [0 : 0]
.addra(PGM_WR_ADDR), // Bus [10 : 0]
.dina(PGM_DI), // Bus [23 : 0]
.clkb(CLK),
.addrb(pc), // Bus [10 : 0]
.doutb(pgm_doutb)); // Bus [23 : 0]
.addra(pc), // Bus [10 : 0]
.douta(pgm_doutb)); // Bus [23 : 0]
wire [23:0] opcode = pgm_doutb;
wire [1:0] op = opcode[23:22];
wire [1:0] op_pselect = opcode[21:20];
wire [3:0] op_alu = opcode[19:16];
wire op_asl = opcode[15];
wire [1:0] op_dpl = opcode[14:13];
wire [3:0] op_dphm = opcode[12:9];
wire op_rpdcr = opcode[8];
wire [3:0] op_src = opcode[7:4];
wire [3:0] op_dst = opcode[3:0];
wire [23:0] opcode_w = pgm_doutb;
reg [23:0] opcode;
reg [1:0] op;
reg [1:0] op_pselect;
reg [3:0] op_alu;
reg op_asl;
reg [1:0] op_dpl;
reg [3:0] op_dphm;
reg op_rpdcr;
reg [3:0] op_src;
reg [3:0] op_dst;
wire [9:0] dat_addra;
wire [15:0] dat_dina;
@ -100,23 +101,20 @@ wire [15:0] dat_doutb;
upd77c25_datrom datrom (
.clka(CLK),
.wea(DAT_WR), // Bus [0 : 0]
.addra(DAT_WR_ADDR), // Bus [9 : 0]
.dina(DAT_DI), // Bus [15 : 0]
.clkb(CLK),
.addrb(regs_rp), // Bus [9 : 0]
.doutb(dat_doutb)); // Bus [15 : 0]
.addra(regs_rp), // Bus [9 : 0]
.douta(dat_doutb)); // Bus [15 : 0]
wire [15:0] ram_douta;
wire [7:0] ram_addra;
upd77c25_datram datram (
.clka(CLK),
.wea(ram_wea), // Bus [0 : 0]
.addra({regs_dph | (op_dst == 4'b1100 ? 4'b0100 : 4'b0000), regs_dpl}), // Bus [7 : 0]
.addra(ram_addra), // Bus [7 : 0]
.dina(ram_dina), // Bus [15 : 0]
.douta(ram_douta)); // Bus [15 : 0]
assign ram_wea = ((op != I_JP) && op_dst == 4'b1111 && insn_state == 2'b01);
assign ram_wea = ((op != I_JP) && op_dst == 4'b1111 && insn_state == 3'b100);
assign ram_addra = {regs_dph | ((insn_state == 3'b101 && op_dst == 4'b1100) ? 4'b0100 : 4'b0000), regs_dpl};
reg signed [15:0] regs_k;
reg signed [15:0] regs_l;
reg [15:0] regs_trb;
@ -126,30 +124,43 @@ reg [15:0] regs_sr;
reg [15:0] regs_si;
reg [3:0] regs_sp;
reg cond_true;
wire [8:0] jp_brch = opcode[21:13];
wire [10:0] jp_na = opcode[12:2];
reg [8:0] jp_brch;
reg [10:0] jp_na;
wire [15:0] ld_id = opcode[21:6];
wire [3:0] ld_dst = opcode[3:0];
reg [15:0] ld_id;
reg [3:0] ld_dst;
wire [31:0] mul_result = regs_k * regs_l;
wire [15:0] regs_m = mul_result[30:15];
wire [15:0] regs_n = {mul_result[14:0], 1'b0};
reg [15:0] regs_m;
reg [15:0] regs_n;
reg signed [15:0] alu_p;
reg signed [15:0] alu_q;
reg signed [15:0] alu_r;
reg [15:0] alu_p;
reg [15:0] alu_q;
reg [15:0] alu_r;
reg [1:0] alu_store;
reg [15:0] stack [15:0];
reg [15:0] idb;
reg signed [15:0] regs_ab [1:0];
reg [15:0] regs_ab [1:0];
/*assign DR = regs_dr;
assign SR = regs_sr;
assign PC = pc;
assign A = regs_ab[0];
assign B = regs_ab[1];
assign FL_A = {flags_s1[0],flags_s0[0],flags_c[0],flags_z[0],flags_ov1[0],flags_ov0[0]};
assign FL_B = {flags_s1[1],flags_s0[1],flags_c[1],flags_z[1],flags_ov1[1],flags_ov0[1]};
*/
initial begin
insn_state = 2'b10;
alu_store = 2'b11;
insn_state = 3'b110;
regs_sp = 4'b0000;
pc = 11'b0;
regs_sr = 16'b0;
@ -160,131 +171,78 @@ initial begin
regs_l = 16'b0;
regs_ab[0] = 16'b0;
regs_ab[1] = 16'b0;
flags_r[0] = 6'b0;
flags_r[1] = 6'b0;
flags_ov0 = 2'b0;
flags_ov1 = 2'b0;
flags_z = 2'b0;
flags_c = 2'b0;
flags_s0 = 2'b0;
flags_s1 = 2'b0;
regs_tr = 16'b0;
regs_trb = 16'b0;
regs_dr = 16'b0;
end
always @(regs_trb, regs_ab[0], regs_ab[1], regs_tr, regs_dph,
regs_dpl, regs_rp, dat_doutb, flags_r[0][FL_S1],
regs_dr, regs_sr, regs_k, regs_l, ram_douta, op_src)
begin
case(op_src)
4'b0000: idb = regs_trb;
4'b0001: idb = regs_ab[0];
4'b0010: idb = regs_ab[1];
4'b0011: idb = regs_tr;
4'b0100: idb = {regs_dph,regs_dpl};
4'b0101: idb = regs_rp;
4'b0110: idb = dat_doutb; // Address: [regs_rp]
4'b0111: idb = flags_r[0][FL_S1] ? 16'h7fff : 16'h8000;
4'b1000: idb = regs_dr;
4'b1001: idb = regs_dr;
4'b1010: idb = regs_sr;
4'b1101: idb = regs_k;
4'b1110: idb = regs_l;
4'b1111: idb = ram_douta; // Address: [regs_dp]
endcase
always @(posedge CLK) begin
end
always @(op_pselect, ram_douta, idb, regs_m, regs_n) begin
case(op_pselect)
2'b00:
alu_p = ram_douta;
2'b01:
alu_p = idb;
2'b10:
alu_p = regs_m;
2'b11:
alu_p = regs_n;
endcase
end
always @(op_asl, regs_ab[0], regs_ab[1], flags_r[0], flags_r[1]) begin
alu_q = regs_ab[op_asl];
flags_in = flags_r[op_asl];
end
always @(op_alu, alu_p, alu_q, flags_in[FL_C]) begin
case(op_alu)
4'b0001: alu_r = alu_q | alu_p;
4'b0010: alu_r = alu_q & alu_p;
4'b0011: alu_r = alu_q ^ alu_p;
4'b0100: alu_r = alu_q - alu_p;
4'b0101: alu_r = alu_q + alu_p;
4'b0110: alu_r = alu_q - alu_p - flags_in[FL_C];
4'b0111: alu_r = alu_q + alu_p + flags_in[FL_C];
4'b1000: alu_r = alu_q - 1;
4'b1001: alu_r = alu_q + 1;
4'b1010: alu_r = ~alu_q;
4'b1011: alu_r = alu_q >>> 1;
4'b1100: alu_r = (alu_q << 1) | flags_in[FL_C];
4'b1101: alu_r = (alu_q << 2) | 2'b11;
4'b1110: alu_r = (alu_q << 4) | 4'b1111;
4'b1111: alu_r = {alu_q[7:0], alu_q[15:8]};
endcase
end
always @(op_alu, alu_r, flags_in, alu_p, alu_q) begin
flags_out = flags_in;
flags_out[FL_Z] = (alu_r == 0);
flags_out[FL_S0] = alu_r[15];
case(op_alu)
4'b0001, 4'b0010, 4'b0011, 4'b1010, 4'b1101, 4'b1110, 4'b1111: begin
flags_out[FL_C] = 0;
flags_out[FL_OV0] = 0;
flags_out[FL_OV1] = 0;
end
4'b0100, 4'b0101, 4'b0110, 4'b0111, 4'b1000, 4'b1001: begin
if(op_alu[0]) begin
flags_out[FL_OV0] = (alu_q ^ alu_r) & ~(alu_q ^ alu_p) & 16'h8000;
flags_out[FL_C] = (alu_r < alu_q);
end else begin
flags_out[FL_OV0] = (alu_q ^ alu_r) & (alu_q ^ alu_p) & 16'h8000;
flags_out[FL_C] = (alu_r > alu_q);
end
if(flags_out[FL_OV0]) begin
flags_out[FL_S1] = flags_in[FL_OV0] ^ !(alu_r & 16'h8000);
flags_out[FL_OV1] = !flags_in[FL_OV1];
end
end
4'b1011: begin
flags_out[FL_C] = alu_q[0];
flags_out[FL_OV0] = 0;
flags_out[FL_OV1] = 0;
end
4'b1100: begin
flags_out[FL_C] = alu_q[15];
flags_out[FL_OV0] = 0;
flags_out[FL_OV1] = 0;
end
endcase
end
reg [5:0] reg_oe_sreg;
initial reg_oe_sreg = 6'b111111;
always @(posedge CLK) reg_oe_sreg <= {reg_oe_sreg[4:0], nRD};
wire reg_oe_falling = !nCS && (reg_oe_sreg[3:0] == 4'b1000);
wire reg_oe_falling = !nCS && (reg_oe_sreg[3:0] == 4'b1110);
reg [1:0] reg_we_sreg;
always @(posedge CLK) reg_we_sreg <= {reg_we_sreg[0], nWR};
wire reg_we_rising = !nCS && (reg_we_sreg[1:0] == 2'b01);
reg [3:0] reg_we_sreg;
initial reg_we_sreg = 4'b1111;
always @(posedge CLK) reg_we_sreg <= {reg_we_sreg[2:0], nWR};
wire reg_we_rising = !nCS && (reg_we_sreg[3:0] == 4'b0001);
always @(posedge CLK) begin
if(RST) begin
if(reg_we_rising && A0 == 1'b0) begin
if((op_src == 4'b1000 && op[1] == 1'b0 && insn_state == 3'b011)
|| (op_dst == 4'b0110 && op != 2'b10 && insn_state == 3'b011)) regs_sr[SR_RQM] <= 1'b1;
else if(reg_we_rising && A0 == 1'b0) begin
if(!regs_sr[SR_DRC]) begin
if(regs_sr[SR_DRS] == 1'b1) begin
regs_sr[SR_RQM] <= 1'b0;
end
end else begin
regs_sr[SR_RQM] <= 1'b0;
end
end else if(reg_oe_falling) begin
case(A0)
1'b0: begin
if(!regs_sr[SR_DRC]) begin
if(regs_sr[SR_DRS] == 1'b1) begin
regs_sr[SR_RQM] <= 1'b0;
end
end else begin
regs_sr[SR_RQM] <= 1'b0;
end
end
endcase
end
end else begin
regs_sr[SR_RQM] <= 1'b0;
end
end
always @(posedge CLK) begin
if(RST) begin
if(ld_dst == 4'b0110 && insn_state == 3'b011) begin
if (op == I_OP || op == I_RT) regs_dr <= idb;
else if (op == I_LD) regs_dr <= ld_id;
end
else if(reg_we_rising && A0 == 1'b0) begin
if(!regs_sr[SR_DRC]) begin
if(regs_sr[SR_DRS] == 1'b0) begin
regs_sr[SR_DRS] <= 1'b1;
regs_dr[7:0] <= DI;
end else begin
regs_sr[SR_DRS] <= 1'b0;
regs_sr[SR_RQM] <= 1'b0;
regs_dr[15:8] <= DI;
end
end else begin
regs_sr[SR_RQM] <= 1'b0;
regs_dr[7:0] <= DI;
end
end else if(reg_oe_falling) begin
@ -296,28 +254,18 @@ always @(posedge CLK) begin
DO <= regs_dr[7:0];
end else begin
regs_sr[SR_DRS] <= 1'b0;
regs_sr[SR_RQM] <= 1'b0;
DO <= regs_dr[15:8];
end
end else begin
regs_sr[SR_RQM] <= 1'b0;
DO <= regs_dr[7:0];
DO <= regs_dr[7:0]; // regs_dr[7:0];
end
end
1'b1: DO <= regs_sr[15:8];
1'b1: DO <= regs_sr[15:8]; // regs_sr[15:8];
endcase
end
if(op_src == 4'b1000 && op[1] == 1'b0) regs_sr[SR_RQM] <= 1;
else if(op_dst == 4'b0110 && op != 2'b10) regs_sr[SR_RQM] <= 1;
if(op_dst == 4'b0110 && insn_state == 2'b00) begin
if (op == I_OP || op == I_RT) regs_dr <= idb;
else if (op == I_LD) regs_dr <= ld_id;
end
end else begin
regs_dr <= 16'h0000;
regs_sr[SR_DRS] <= 1'b0;
regs_sr[SR_RQM] <= 1'b0;
regs_dr <= 16'h0000;
DO <= 8'h00;
end
end
@ -325,15 +273,85 @@ end
always @(posedge CLK) begin
if(RST) begin
case(insn_state)
2'b00: begin
insn_state <= 2'b01;
3'b000: begin
insn_state <= 3'b001;
opcode <= opcode_w;
op <= opcode_w[23:22];
op_pselect <= opcode_w[21:20];
op_alu <= opcode_w[19:16];
op_asl <= opcode_w[15];
op_dpl <= opcode_w[14:13];
op_dphm <= opcode_w[12:9];
op_rpdcr <= opcode_w[8];
op_src <= opcode_w[7:4];
op_dst <= opcode_w[3:0];
jp_brch = opcode_w[21:13];
jp_na <= opcode_w[12:2];
ld_id <= opcode_w[21:6];
ld_dst <= opcode_w[3:0];
regs_m <= {mul_result[31], mul_result[29:15]};
regs_n <= {mul_result[14:0], 1'b0};
end
3'b001: begin
insn_state <= 3'b010;
case(op)
I_OP, I_RT: begin
case(op_src)
4'b0000: idb <= regs_trb;
4'b0001: idb <= regs_ab[0];
4'b0010: idb <= regs_ab[1];
4'b0011: idb <= regs_tr;
4'b0100: idb <= {regs_dph,regs_dpl};
4'b0101: idb <= regs_rp;
4'b0110: idb <= dat_doutb; // Address: [regs_rp]
4'b0111: idb <= flags_s1[0] ? 16'h7fff : 16'h8000;
4'b1000: idb <= regs_dr;
4'b1001: idb <= regs_dr;
4'b1010: idb <= regs_sr;
4'b1101: idb <= regs_k;
4'b1110: idb <= regs_l;
4'b1111: idb <= ram_douta; // Address: [regs_dp]
endcase
end
endcase
end
3'b010: begin
insn_state <= 3'b101;
case(op)
I_OP, I_RT: begin
alu_q <= regs_ab[op_asl];
if(op_alu[3:1] == 3'b100) begin
alu_p <= 16'h0001;
end else begin
case(op_pselect)
2'b00:
alu_p <= ram_douta;
2'b01:
alu_p <= idb;
2'b10:
alu_p <= regs_m;
2'b11:
alu_p <= regs_n;
endcase
end
end
endcase
end
3'b011: begin
insn_state <= 3'b100;
case(op)
I_OP, I_RT: begin
// if(op_src == 4'b1000) regs_sr[SR_RQM] <= 1;
regs_ab[op_asl] <= alu_r;
case(op_dst)
4'b0001: regs_ab[0] <= idb;
4'b0010: regs_ab[1] <= idb;
4'b0001: begin
regs_ab[0] <= idb;
alu_store <= 2'b10;
end
4'b0010: begin
regs_ab[1] <= idb;
alu_store <= 2'b01;
end
4'b0011: regs_tr <= idb;
4'b0100: {regs_dph,regs_dpl} <= idb[7:0];
4'b0101: regs_rp <= idb;
@ -346,6 +364,8 @@ always @(posedge CLK) begin
regs_sr[9] <= idb[9];
regs_sr[8] <= idb[8];
regs_sr[7] <= idb[7];
regs_sr[1] <= idb[1];
regs_sr[0] <= idb[0];
end
4'b1010: regs_k <= idb;
4'b1011: begin
@ -360,7 +380,44 @@ always @(posedge CLK) begin
4'b1110: regs_trb <= idb;
4'b1111: ram_dina_r <= idb;
endcase
flags_r[op_asl] <= flags_out;
if(|op_alu) begin
flags_z[op_asl] <= (alu_r == 0);
flags_s0[op_asl] <= alu_r[15];
end
case(op_alu)
4'b0001, 4'b0010, 4'b0011, 4'b1010, 4'b1101, 4'b1110, 4'b1111: begin
flags_c[op_asl] <= 0;
flags_ov0[op_asl] <= 0;
flags_ov1[op_asl] <= 0;
end
4'b0100, 4'b0101, 4'b0110, 4'b0111, 4'b1000, 4'b1001: begin
if(op_alu[0]) begin
flags_c[op_asl] <= (alu_r < alu_q);
flags_ov0[op_asl] <= (alu_q[15] ^ alu_r[15]) & ~(alu_q[15] ^ alu_p[15]);
if((alu_q[15] ^ alu_r[15]) & ~(alu_q[15] ^ alu_p[15])) begin
flags_s1[op_asl] <= flags_ov1[op_asl] ^ ~alu_r[15];
flags_ov1[op_asl] <= ~flags_ov1[op_asl];
end
end else begin
flags_c[op_asl] <= (alu_r > alu_q);
flags_ov0[op_asl] <= (alu_q[15] ^ alu_r[15]) & (alu_q[15] ^ alu_p[15]);
if((alu_q[15] ^ alu_r[15]) & (alu_q[15] ^ alu_p[15])) begin
flags_s1[op_asl] <= flags_ov1[op_asl] ^ ~alu_r[15];
flags_ov1[op_asl] <= ~flags_ov1[op_asl];
end
end
end
4'b1011: begin
flags_c[op_asl] <= alu_q[0];
flags_ov0[op_asl] <= 0;
flags_ov1[op_asl] <= 0;
end
4'b1100: begin
flags_c[op_asl] <= alu_q[15];
flags_ov0[op_asl] <= 0;
flags_ov1[op_asl] <= 0;
end
endcase
end
I_LD: begin
case(ld_dst)
@ -378,6 +435,8 @@ always @(posedge CLK) begin
regs_sr[9] <= ld_id[9];
regs_sr[8] <= ld_id[8];
regs_sr[7] <= ld_id[7];
regs_sr[1] <= ld_id[1];
regs_sr[0] <= ld_id[0];
end
4'b1010: regs_k <= ld_id;
4'b1011: begin
@ -397,30 +456,30 @@ always @(posedge CLK) begin
case(jp_brch)
9'b100_000_000: cond_true <= 1;
9'b101_000_000: cond_true <= 1;
9'b010_000_000: cond_true <= (flags_r[0][FL_C] == 0);
9'b010_000_010: cond_true <= (flags_r[0][FL_C] == 1);
9'b010_000_100: cond_true <= (flags_r[1][FL_C] == 0);
9'b010_000_110: cond_true <= (flags_r[1][FL_C] == 1);
9'b010_001_000: cond_true <= (flags_r[0][FL_Z] == 0);
9'b010_001_010: cond_true <= (flags_r[0][FL_Z] == 1);
9'b010_001_100: cond_true <= (flags_r[1][FL_Z] == 0);
9'b010_001_110: cond_true <= (flags_r[1][FL_Z] == 1);
9'b010_010_000: cond_true <= (flags_r[0][FL_OV0] == 0);
9'b010_010_010: cond_true <= (flags_r[0][FL_OV0] == 1);
9'b010_010_100: cond_true <= (flags_r[1][FL_OV0] == 0);
9'b010_010_110: cond_true <= (flags_r[1][FL_OV0] == 1);
9'b010_011_000: cond_true <= (flags_r[0][FL_OV1] == 0);
9'b010_011_010: cond_true <= (flags_r[0][FL_OV1] == 1);
9'b010_011_100: cond_true <= (flags_r[1][FL_OV1] == 0);
9'b010_011_110: cond_true <= (flags_r[1][FL_OV1] == 1);
9'b010_100_000: cond_true <= (flags_r[0][FL_S0] == 0);
9'b010_100_010: cond_true <= (flags_r[0][FL_S0] == 1);
9'b010_100_100: cond_true <= (flags_r[1][FL_S0] == 0);
9'b010_100_110: cond_true <= (flags_r[1][FL_S0] == 1);
9'b010_101_000: cond_true <= (flags_r[0][FL_S1] == 0);
9'b010_101_010: cond_true <= (flags_r[0][FL_S1] == 1);
9'b010_101_100: cond_true <= (flags_r[1][FL_S1] == 0);
9'b010_101_110: cond_true <= (flags_r[1][FL_S1] == 1);
9'b010_000_000: cond_true <= (flags_c[0] == 0);
9'b010_000_010: cond_true <= (flags_c[0] == 1);
9'b010_000_100: cond_true <= (flags_c[1] == 0);
9'b010_000_110: cond_true <= (flags_c[1] == 1);
9'b010_001_000: cond_true <= (flags_z[0] == 0);
9'b010_001_010: cond_true <= (flags_z[0] == 1);
9'b010_001_100: cond_true <= (flags_z[1] == 0);
9'b010_001_110: cond_true <= (flags_z[1] == 1);
9'b010_010_000: cond_true <= (flags_ov0[0] == 0);
9'b010_010_010: cond_true <= (flags_ov0[0] == 1);
9'b010_010_100: cond_true <= (flags_ov0[1] == 0);
9'b010_010_110: cond_true <= (flags_ov0[1] == 1);
9'b010_011_000: cond_true <= (flags_ov1[0] == 0);
9'b010_011_010: cond_true <= (flags_ov1[0] == 1);
9'b010_011_100: cond_true <= (flags_ov1[1] == 0);
9'b010_011_110: cond_true <= (flags_ov1[1] == 1);
9'b010_100_000: cond_true <= (flags_s0[0] == 0);
9'b010_100_010: cond_true <= (flags_s0[0] == 1);
9'b010_100_100: cond_true <= (flags_s0[1] == 0);
9'b010_100_110: cond_true <= (flags_s0[1] == 1);
9'b010_101_000: cond_true <= (flags_s1[0] == 0);
9'b010_101_010: cond_true <= (flags_s1[0] == 1);
9'b010_101_100: cond_true <= (flags_s1[1] == 0);
9'b010_101_110: cond_true <= (flags_s1[1] == 1);
9'b010_110_000: cond_true <= (regs_dpl == 0);
9'b010_110_001: cond_true <= (regs_dpl != 0);
9'b010_110_010: cond_true <= (regs_dpl == 4'b1111);
@ -432,9 +491,14 @@ always @(posedge CLK) begin
end
endcase
end
2'b01: begin
3'b100: begin
insn_state <= 3'b110;
case(op)
I_OP, I_RT: begin
if(|op_alu && alu_store[op_asl]) regs_ab[op_asl] <= alu_r;
alu_store <= 2'b11;
if(op_rpdcr) regs_rp <= regs_rp - 1;
case(op_dpl)
2'b01: regs_dpl <= regs_dpl + 1;
@ -452,7 +516,7 @@ always @(posedge CLK) begin
if(cond_true) begin
pc <= jp_na;
if(jp_brch[8:6] == 3'b101) begin
stack[regs_sp] <= pc;
stack[regs_sp] <= pc + 1;
regs_sp <= regs_sp + 1;
end
end else pc <= pc + 1;
@ -461,12 +525,35 @@ always @(posedge CLK) begin
pc <= pc + 1;
end
endcase
insn_state <= 2'b10;
end
2'b10: insn_state <= 2'b00;
3'b110: insn_state <= 3'b111;
3'b111: insn_state <= 3'b000;
3'b101: begin
insn_state <= 3'b011;
if(op[1] == 1'b0) begin
case(op_alu)
4'b0001: alu_r <= alu_q | alu_p;
4'b0010: alu_r <= alu_q & alu_p;
4'b0011: alu_r <= alu_q ^ alu_p;
4'b0100: alu_r <= alu_q - alu_p;
4'b0101: alu_r <= alu_q + alu_p;
4'b0110: alu_r <= alu_q - alu_p - flags_c[~op_asl];
4'b0111: alu_r <= alu_q + alu_p + flags_c[~op_asl];
4'b1000: alu_r <= alu_q - alu_p;
4'b1001: alu_r <= alu_q + alu_p;
4'b1010: alu_r <= ~alu_q;
4'b1011: alu_r <= {alu_q[15], alu_q[15:1]};
4'b1100: alu_r <= {alu_q[14:0], flags_c[~op_asl]};
4'b1101: alu_r <= {alu_q[13:0], 2'b11};
4'b1110: alu_r <= {alu_q[11:0], 4'b1111};
4'b1111: alu_r <= {alu_q[7:0], alu_q[15:8]};
endcase
end
end
endcase
end else begin
insn_state <= 2'b10;
insn_state <= 3'b110;
pc <= 11'b0;
regs_sp <= 4'b0000;
cond_true <= 0;
@ -484,8 +571,12 @@ always @(posedge CLK) begin
regs_l <= 16'b0;
regs_ab[0] <= 16'b0;
regs_ab[1] <= 16'b0;
flags_r[0] <= 6'b0;
flags_r[1] <= 6'b0;
flags_ov0 <= 2'b0;
flags_ov1 <= 2'b0;
flags_z <= 2'b0;
flags_c <= 2'b0;
flags_s0 <= 2'b0;
flags_s1 <= 2'b0;
regs_tr <= 16'b0;
regs_trb <= 16'b0;
end