X-Git-Url: http://git.joshuawise.com/fpgaboy.git/blobdiff_plain/a02672555adf08bfd6755cf70599895dd2155a24..2e642f1f5c3cb12c3a34983d9fbdd0141ca34931:/GBZ80Core.v diff --git a/GBZ80Core.v b/GBZ80Core.v index afa4495..fc77377 100644 --- a/GBZ80Core.v +++ b/GBZ80Core.v @@ -101,19 +101,28 @@ module GBZ80Core( registers[ 9] <= 0; registers[10] <= 0; registers[11] <= 0; + ie <= 0; + rd <= 1; + wr <= 0; + newcycle <= 1; + state <= 0; + cycle <= 0; end always @(posedge clk) case (state) `STATE_FETCH: begin - if (wr) - buswdata <= wdata; - if (newcycle) + if (newcycle) begin busaddress <= {registers[`REG_PCH], registers[`REG_PCL]}; - else + buswr <= 0; + busrd <= 1; + end else begin busaddress <= address; - buswr <= wr; - busrd <= rd; + buswr <= wr; + busrd <= rd; + if (wr) + buswdata <= wdata; + end state <= `STATE_DECODE; end `STATE_DECODE: begin @@ -122,8 +131,10 @@ module GBZ80Core( rdata <= busdata; newcycle <= 0; cycle <= 0; - end else + end else begin if (rd) rdata <= busdata; + cycle <= cycle + 1; + end buswr <= 0; busrd <= 0; wr <= 0; @@ -421,32 +432,29 @@ module GBZ80Core( casex (opcode) `INSN_LD_reg_imm8: case (cycle) - 0: cycle <= 1; + 0: begin end 1: case (opcode[5:3]) - `INSN_reg_A: begin registers[`REG_A] <= rdata; cycle <= 0; end - `INSN_reg_B: begin registers[`REG_B] <= rdata; cycle <= 0; end - `INSN_reg_C: begin registers[`REG_C] <= rdata; cycle <= 0; end - `INSN_reg_D: begin registers[`REG_D] <= rdata; cycle <= 0; end - `INSN_reg_E: begin registers[`REG_E] <= rdata; cycle <= 0; end - `INSN_reg_H: begin registers[`REG_H] <= rdata; cycle <= 0; end - `INSN_reg_L: begin registers[`REG_L] <= rdata; cycle <= 0; end - `INSN_reg_dHL: cycle <= 2; + `INSN_reg_A: begin registers[`REG_A] <= rdata; end + `INSN_reg_B: begin registers[`REG_B] <= rdata; end + `INSN_reg_C: begin registers[`REG_C] <= rdata; end + `INSN_reg_D: begin registers[`REG_D] <= rdata; end + `INSN_reg_E: begin registers[`REG_E] <= rdata; end + `INSN_reg_H: begin registers[`REG_H] <= rdata; end + `INSN_reg_L: begin registers[`REG_L] <= rdata; end + `INSN_reg_dHL: begin /* Go off to cycle 2 */ end endcase - 2: cycle <= 0; + 2: begin end endcase `INSN_HALT: begin /* Nothing needs happen here. */ /* XXX Interrupts needed for HALT. */ end `INSN_LD_HL_reg: begin - case (cycle) - 0: cycle <= 1; - 1: cycle <= 0; - endcase + /* Nothing of interest here */ end `INSN_LD_reg_HL: begin case (cycle) - 0: cycle <= 1; + 0: begin end 1: begin case (opcode[5:3]) `INSN_reg_A: registers[`REG_A] <= tmp; @@ -457,7 +465,6 @@ module GBZ80Core( `INSN_reg_H: registers[`REG_H] <= tmp; `INSN_reg_L: registers[`REG_L] <= tmp; endcase - cycle <= 0; end endcase end @@ -474,7 +481,7 @@ module GBZ80Core( end `INSN_LD_reg_imm16: begin case (cycle) - 0: cycle <= 1; + 0: begin /* */ end 1: begin case (opcode[5:4]) `INSN_reg16_BC: registers[`REG_C] <= rdata; @@ -482,7 +489,6 @@ module GBZ80Core( `INSN_reg16_HL: registers[`REG_L] <= rdata; `INSN_reg16_SP: registers[`REG_SPL] <= rdata; endcase - cycle <= 2; end 2: begin case (opcode[5:4]) @@ -491,45 +497,29 @@ module GBZ80Core( `INSN_reg16_HL: registers[`REG_H] <= rdata; `INSN_reg16_SP: registers[`REG_SPH] <= rdata; endcase - cycle <= 0; end endcase end `INSN_LD_SP_HL: begin case (cycle) - 0: begin - cycle <= 1; - registers[`REG_SPH] <= tmp; - end - 1: begin - cycle <= 0; - registers[`REG_SPL] <= tmp; - end + 0: registers[`REG_SPH] <= tmp; + 1: registers[`REG_SPL] <= tmp; endcase end `INSN_PUSH_reg: begin /* PUSH is 16 cycles! */ case (cycle) - 0: begin - {registers[`REG_SPH],registers[`REG_SPL]} <= - {registers[`REG_SPH],registers[`REG_SPL]} - 1; - cycle <= 1; - end - 1: begin - {registers[`REG_SPH],registers[`REG_SPL]} <= - {registers[`REG_SPH],registers[`REG_SPL]} - 1; - cycle <= 2; - end - 2: cycle <= 3; - 3: cycle <= 0; + 0: {registers[`REG_SPH],registers[`REG_SPL]} <= + {registers[`REG_SPH],registers[`REG_SPL]} - 1; + 1: {registers[`REG_SPH],registers[`REG_SPL]} <= + {registers[`REG_SPH],registers[`REG_SPL]} - 1; + 2: begin /* type F */ end + 3: begin /* type F */ end endcase end `INSN_POP_reg: begin /* POP is 12 cycles! */ case (cycle) - 0: begin - cycle <= 1; - {registers[`REG_SPH],registers[`REG_SPL]} <= - {registers[`REG_SPH],registers[`REG_SPL]} + 1; - end + 0: {registers[`REG_SPH],registers[`REG_SPL]} <= + {registers[`REG_SPH],registers[`REG_SPL]} + 1; 1: begin case (opcode[5:4]) `INSN_stack_AF: registers[`REG_F] <= rdata; @@ -539,7 +529,6 @@ module GBZ80Core( endcase {registers[`REG_SPH],registers[`REG_SPL]} <= {registers[`REG_SPH],registers[`REG_SPL]} + 1; - cycle <= 2; end 2: begin case (opcode[5:4]) @@ -548,25 +537,20 @@ module GBZ80Core( `INSN_stack_DE: registers[`REG_D] <= rdata; `INSN_stack_HL: registers[`REG_H] <= rdata; endcase - cycle <= 0; end endcase end `INSN_LDH_AC: begin case (cycle) - 0: cycle <= 1; - 1: begin - cycle <= 0; - if (opcode[4]) - registers[`REG_A] <= rdata; - end + 0: begin /* Type F */ end + 1: if (opcode[4]) + registers[`REG_A] <= rdata; endcase end `INSN_LDx_AHL: begin case (cycle) - 0: cycle <= 1; + 0: begin /* Type F */ end 1: begin - cycle <= 0; if (opcode[3]) registers[`REG_A] <= rdata; {registers[`REG_H],registers[`REG_L]} <= @@ -579,7 +563,6 @@ module GBZ80Core( `INSN_ALU8: begin if ((opcode[2:0] == `INSN_reg_dHL) && (cycle == 0)) begin /* Sit on our asses. */ - cycle <= 1; end else begin /* Actually do the computation! */ case (opcode[5:3]) `INSN_alu_ADD: begin @@ -639,29 +622,19 @@ module GBZ80Core( `INSN_NOP: begin /* NOP! */ end `INSN_RST: begin case (cycle) - 0: cycle <= 1; - 1: cycle <= 2; - 2: cycle <= 3; - 3: begin - cycle <= 0; - {registers[`REG_SPH],registers[`REG_SPL]} <= - {registers[`REG_SPH],registers[`REG_SPL]}-2; - end + 0: begin /* type F */ end + 1: begin /* type F */ end + 2: begin /* type F */ end + 3: {registers[`REG_SPH],registers[`REG_SPL]} <= + {registers[`REG_SPH],registers[`REG_SPL]}-2; endcase end `INSN_RET: begin case (cycle) - 0: cycle <= 1; - 1: begin - cycle <= 2; - registers[`REG_PCL] <= rdata; - end - 2: begin - cycle <= 3; - registers[`REG_PCH] <= rdata; - end + 0: begin /* type F */ end + 1: registers[`REG_PCL] <= rdata; + 2: registers[`REG_PCH] <= rdata; 3: begin - cycle <= 0; {registers[`REG_SPH],registers[`REG_SPL]} <= {registers[`REG_SPH],registers[`REG_SPL]} + 2; if (opcode[4]) /* RETI */ @@ -671,27 +644,15 @@ module GBZ80Core( end `INSN_CALL: begin case (cycle) - 0: cycle <= 1; - 1: begin - cycle <= 2; - tmp <= rdata; // tmp contains newpcl - end - 2: begin - cycle <= 3; - tmp2 <= rdata; // tmp2 contains newpch - end - 3: begin - cycle <= 4; - end - 4: begin - cycle <= 5; - registers[`REG_PCH] <= tmp2; - end + 0: begin /* type F */ end + 1: tmp <= rdata; // tmp contains newpcl + 2: tmp2 <= rdata; // tmp2 contains newpch + 3: begin /* type F */ end + 4: registers[`REG_PCH] <= tmp2; 5: begin {registers[`REG_SPH],registers[`REG_SPL]} <= {registers[`REG_SPH],registers[`REG_SPL]} - 2; registers[`REG_PCL] <= tmp; - cycle <= 0; end endcase end @@ -764,20 +725,22 @@ endmodule //endmodule module CoreTop( - input iclk, + input iclk, xtal, output wire [7:0] leds, - output serio); + output serio, + output wire [3:0] digits, + output wire [7:0] seven); wire clk; - IBUFG ibuf (.O(clk), .I(iclk)); + //IBUFG ibuf (.O(clk), .I(iclk)); + + CPUDCM dcm (.CLKIN_IN(xtal), .CLKFX_OUT(clk)); wire [15:0] addr; wire [7:0] data; wire wr, rd; - wire [7:0] swleds; - - assign leds = clk?{rd,wr,addr[5:0]}:data[7:0]; + assign leds = iclk?{rd,wr,addr[5:0]}:data[7:0]; GBZ80Core core( .clk(clk), @@ -793,32 +756,39 @@ module CoreTop( .wr(wr), .rd(rd)); + AddrMon amon( + .addr(addr), + .clk(xtal), + .digit(digits), + .out(seven) + ); + assign serio = 0; endmodule -//module TestBench(); -// reg clk = 0; -// wire [15:0] addr; -// wire [7:0] data; -// wire wr, rd; +module TestBench(); + reg clk = 0; + wire [15:0] addr; + wire [7:0] data; + wire wr, rd; // wire [7:0] leds; // wire [7:0] switches; -// always #10 clk <= ~clk; -// GBZ80Core core( -// .clk(clk), -// .busaddress(addr), -// .busdata(data), -// .buswr(wr), -// .busrd(rd)); + always #10 clk <= ~clk; + GBZ80Core core( + .clk(clk), + .busaddress(addr), + .busdata(data), + .buswr(wr), + .busrd(rd)); -// ROM rom( -// .clk(clk), -// .address(addr), -// .data(data), -// .wr(wr), -// .rd(rd)); + ROM rom( + .clk(clk), + .address(addr), + .data(data), + .wr(wr), + .rd(rd)); // InternalRAM ram( // .address(addr), @@ -844,4 +814,4 @@ endmodule // .rd(rd), // .switches(switches), // .leds(leds)); -//endmodule +endmodule