X-Git-Url: http://git.joshuawise.com/fpgaboy.git/blobdiff_plain/7d9d69c71187b4891b2281ab58ab8360e43290c2..537e1f833b8eba858c06053ea6006ea608b9a5cc:/GBZ80Core.v diff --git a/GBZ80Core.v b/GBZ80Core.v index 3bc2b16..3bbaee8 100644 --- a/GBZ80Core.v +++ b/GBZ80Core.v @@ -1,42 +1,82 @@ -`define REG_A 0 -`define REG_B 1 -`define REG_C 2 -`define REG_D 3 -`define REG_E 4 -`define REG_F 5 -`define REG_H 6 -`define REG_L 7 -`define REG_SPH 8 -`define REG_SPL 9 -`define REG_PCH 10 -`define REG_PCL 11 - -`define FLAG_Z 8'b10000000 -`define FLAG_N 8'b01000000 -`define FLAG_H 8'b00100000 -`define FLAG_C 8'b00010000 - -`define STATE_FETCH 2'h0 -`define STATE_DECODE 2'h1 +`define REG_A 0 +`define REG_B 1 +`define REG_C 2 +`define REG_D 3 +`define REG_E 4 +`define REG_F 5 +`define REG_H 6 +`define REG_L 7 +`define REG_SPH 8 +`define REG_SPL 9 +`define REG_PCH 10 +`define REG_PCL 11 + +`define _A registers[`REG_A] +`define _B registers[`REG_B] +`define _C registers[`REG_C] +`define _D registers[`REG_D] +`define _E registers[`REG_E] +`define _F registers[`REG_F] +`define _H registers[`REG_H] +`define _L registers[`REG_L] +`define _SPH registers[`REG_SPH] +`define _SPL registers[`REG_SPL] +`define _PCH registers[`REG_PCH] +`define _PCL registers[`REG_PCL] +`define _AF {`_A, `_F} +`define _BC {`_B, `_C} +`define _DE {`_D, `_E} +`define _HL {`_H, `_L} +`define _SP {`_SPH, `_SPL} +`define _PC {`_PCH, `_PCL} + +`define FLAG_Z 8'b10000000 +`define FLAG_N 8'b01000000 +`define FLAG_H 8'b00100000 +`define FLAG_C 8'b00010000 + +`define STATE_FETCH 2'h0 +`define STATE_DECODE 2'h1 `define STATE_EXECUTE 2'h2 `define STATE_WRITEBACK 2'h3 `define INSN_LD_reg_imm8 8'b00xxx110 -`define INSN_HALT 8'b01110110 +`define INSN_HALT 8'b01110110 `define INSN_LD_HL_reg 8'b01110xxx `define INSN_LD_reg_HL 8'b01xxx110 `define INSN_LD_reg_reg 8'b01xxxxxx `define INSN_LD_reg_imm16 8'b00xx0001 `define INSN_LD_SP_HL 8'b11111001 `define INSN_PUSH_reg 8'b11xx0101 -`define INSN_POP_reg 8'b11xx0001 -`define INSN_LDH_AC 8'b111x0010 // Either LDH A,(C) or LDH (C),A -`define INSN_LDx_AHL 8'b001xx010 // LDD/LDI A,(HL) / (HL),A -`define INSN_ALU8 8'b10xxxxxx // 10 xxx yyy -`define INSN_NOP 8'b00000000 -`define INSN_RST 8'b11xxx111 -`define INSN_RET 8'b110x1001 // 1 = RETI, 0 = RET -`define INSN_CALL 8'b11001101 +`define INSN_POP_reg 8'b11xx0001 +`define INSN_LDH_AC 8'b111x0010 // Either LDH A,(C) or LDH (C),A +`define INSN_LDx_AHL 8'b001xx010 // LDD/LDI A,(HL) / (HL),A +`define INSN_ALU8 8'b10xxxxxx // 10 xxx yyy +`define INSN_ALU8IMM 8'b11xxx110 +`define INSN_NOP 8'b00000000 +`define INSN_RST 8'b11xxx111 +`define INSN_RET 8'b110x1001 // 1 = RETI, 0 = RET +`define INSN_RETCC 8'b110xx000 +`define INSN_CALL 8'b11001101 +`define INSN_CALLCC 8'b110xx100 // Not that call/cc. +`define INSN_JP_imm 8'b11000011 +`define INSN_JPCC_imm 8'b110xx010 +`define INSN_ALU_A 8'b00xxx111 +`define INSN_JP_HL 8'b11101001 +`define INSN_JR_imm 8'b00011000 +`define INSN_JRCC_imm 8'b001xx000 +`define INSN_INCDEC16 8'b00xxx011 +`define INSN_VOP_INTR 8'b11111100 // 0xFC is grabbed by the fetch if there is an interrupt pending. +`define INSN_DI 8'b11110011 +`define INSN_EI 8'b11111011 +`define INSN_INCDEC_HL 8'b0011010x +`define INSN_INCDEC_reg8 8'b00xxx10x +`define INSN_LDM_A 8'b111xx000 // 1111 for ld A, x; 1110 for ld x, A; bit 1 specifies 16m8 or 8m8 + +`define INSN_cc_NZ 2'b00 +`define INSN_cc_Z 2'b01 +`define INSN_cc_NC 2'b10 +`define INSN_cc_C 2'b11 `define INSN_reg_A 3'b111 `define INSN_reg_B 3'b000 @@ -45,15 +85,15 @@ `define INSN_reg_E 3'b011 `define INSN_reg_H 3'b100 `define INSN_reg_L 3'b101 -`define INSN_reg_dHL 3'b110 -`define INSN_reg16_BC 2'b00 -`define INSN_reg16_DE 2'b01 -`define INSN_reg16_HL 2'b10 -`define INSN_reg16_SP 2'b11 -`define INSN_stack_AF 2'b11 -`define INSN_stack_BC 2'b00 -`define INSN_stack_DE 2'b01 -`define INSN_stack_HL 2'b10 +`define INSN_reg_dHL 3'b110 +`define INSN_reg16_BC 2'b00 +`define INSN_reg16_DE 2'b01 +`define INSN_reg16_HL 2'b10 +`define INSN_reg16_SP 2'b11 +`define INSN_stack_AF 2'b11 +`define INSN_stack_BC 2'b00 +`define INSN_stack_DE 2'b01 +`define INSN_stack_HL 2'b10 `define INSN_alu_ADD 3'b000 `define INSN_alu_ADC 3'b001 `define INSN_alu_SUB 3'b010 @@ -62,15 +102,31 @@ `define INSN_alu_XOR 3'b101 `define INSN_alu_OR 3'b110 `define INSN_alu_CP 3'b111 // Oh lawd, is dat some CP? +`define INSN_alu_RLCA 3'b000 +`define INSN_alu_RRCA 3'b001 +`define INSN_alu_RLA 3'b010 +`define INSN_alu_RRA 3'b011 +`define INSN_alu_DAA 3'b100 +`define INSN_alu_CPL 3'b101 +`define INSN_alu_SCF 3'b110 +`define INSN_alu_CCF 3'b111 + +`define EXEC_INC_PC `_PC <= `_PC + 1; +`define EXEC_NEXTADDR_PCINC address <= `_PC + 1; +`define EXEC_NEWCYCLE begin newcycle <= 1; rd <= 1; wr <= 0; end +`define EXEC_WRITE(ad, da) begin address <= (ad); wdata <= (da); wr <= 1; end end +`define EXEC_READ(ad) begin address <= (ad); rd <= 1; end end module GBZ80Core( input clk, output reg [15:0] busaddress, /* BUS_* is latched on STATE_FETCH. */ inout [7:0] busdata, - output reg buswr, output reg busrd); + output reg buswr, output reg busrd, + input irq, input [7:0] jaddr, + output reg [1:0] state); - reg [1:0] state = 0; /* State within this bus cycle (see STATE_*). */ - reg [2:0] cycle = 0; /* Cycle for instructions. */ +// reg [1:0] state; /* State within this bus cycle (see STATE_*). */ + reg [2:0] cycle; /* Cycle for instructions. */ reg [7:0] registers[11:0]; @@ -79,14 +135,14 @@ module GBZ80Core( reg [7:0] opcode; /* Opcode from the current machine cycle. */ reg [7:0] rdata, wdata; /* Read data from this bus cycle, or write data for the next. */ - reg rd = 1, wr = 0, newcycle = 1; + reg rd, wr, newcycle; reg [7:0] tmp, tmp2; /* Generic temporary regs. */ reg [7:0] buswdata; assign busdata = buswr ? buswdata : 8'bzzzzzzzz; - reg ie = 0; + reg ie, iedelay; initial begin registers[ 0] <= 0; @@ -101,12 +157,19 @@ module GBZ80Core( registers[ 9] <= 0; registers[10] <= 0; registers[11] <= 0; - ie <= 0; rd <= 1; wr <= 0; newcycle <= 1; state <= 0; cycle <= 0; + busrd <= 0; + buswr <= 0; + busaddress <= 0; + ie <= 0; + iedelay <= 0; + opcode <= 0; + state <= `STATE_WRITEBACK; + cycle <= 0; end always @(posedge clk) @@ -127,7 +190,10 @@ module GBZ80Core( end `STATE_DECODE: begin if (newcycle) begin - opcode <= busdata; + if (ie && irq) + opcode <= `INSN_VOP_INTR; + else + opcode <= busdata; rdata <= busdata; newcycle <= 0; cycle <= 0; @@ -135,6 +201,10 @@ module GBZ80Core( if (rd) rdata <= busdata; cycle <= cycle + 1; end + if (iedelay) begin + ie <= 1; + iedelay <= 0; + end buswr <= 0; busrd <= 0; wr <= 0; @@ -144,285 +214,10 @@ module GBZ80Core( state <= `STATE_EXECUTE; end `STATE_EXECUTE: begin -`define EXEC_INC_PC \ - {registers[`REG_PCH], registers[`REG_PCL]} <= {registers[`REG_PCH], registers[`REG_PCL]} + 1 -`define EXEC_NEXTADDR_PCINC \ - address <= {registers[`REG_PCH], registers[`REG_PCL]} + 1 -`define EXEC_NEWCYCLE \ - newcycle <= 1; rd <= 1; wr <= 0 casex (opcode) - `INSN_LD_reg_imm8: begin - case (cycle) - 0: begin - `EXEC_INC_PC; - `EXEC_NEXTADDR_PCINC; - rd <= 1; - end - 1: begin - `EXEC_INC_PC; - if (opcode[5:3] == `INSN_reg_dHL) begin - address <= {registers[`REG_H], registers[`REG_L]}; - wdata <= rdata; - rd <= 0; - wr <= 1; - end else begin - `EXEC_NEWCYCLE; - end - end - 2: begin - `EXEC_NEWCYCLE; - end - endcase - end - `INSN_HALT: begin - `EXEC_NEWCYCLE; - /* XXX Interrupts needed for HALT. */ - end - `INSN_LD_HL_reg: begin - case (cycle) - 0: begin - case (opcode[2:0]) - `INSN_reg_A: wdata <= registers[`REG_A]; - `INSN_reg_B: wdata <= registers[`REG_B]; - `INSN_reg_C: wdata <= registers[`REG_C]; - `INSN_reg_D: wdata <= registers[`REG_D]; - `INSN_reg_E: wdata <= registers[`REG_E]; - `INSN_reg_H: wdata <= registers[`REG_H]; - `INSN_reg_L: wdata <= registers[`REG_L]; - endcase - address <= {registers[`REG_H], registers[`REG_L]}; - wr <= 1; rd <= 0; - end - 1: begin - `EXEC_INC_PC; - `EXEC_NEWCYCLE; - end - endcase - end - `INSN_LD_reg_HL: begin - case(cycle) - 0: begin - address <= {registers[`REG_H], registers[`REG_L]}; - rd <= 1; - end - 1: begin - tmp <= rdata; - `EXEC_INC_PC; - `EXEC_NEWCYCLE; - end - endcase - end - `INSN_LD_reg_reg: begin - `EXEC_INC_PC; - `EXEC_NEWCYCLE; - case (opcode[2:0]) - `INSN_reg_A: tmp <= registers[`REG_A]; - `INSN_reg_B: tmp <= registers[`REG_B]; - `INSN_reg_C: tmp <= registers[`REG_C]; - `INSN_reg_D: tmp <= registers[`REG_D]; - `INSN_reg_E: tmp <= registers[`REG_E]; - `INSN_reg_H: tmp <= registers[`REG_H]; - `INSN_reg_L: tmp <= registers[`REG_L]; - endcase - end - `INSN_LD_reg_imm16: begin - `EXEC_INC_PC; - case (cycle) - 0: begin - `EXEC_NEXTADDR_PCINC; - rd <= 1; - end - 1: begin - `EXEC_NEXTADDR_PCINC; - rd <= 1; - end - 2: begin `EXEC_NEWCYCLE; end - endcase - end - `INSN_LD_SP_HL: begin - case (cycle) - 0: begin - tmp <= registers[`REG_H]; - end - 1: begin - `EXEC_NEWCYCLE; - `EXEC_INC_PC; - tmp <= registers[`REG_L]; - end - endcase - end - `INSN_PUSH_reg: begin /* PUSH is 16 cycles! */ - case (cycle) - 0: begin - wr <= 1; - address <= {registers[`REG_SPH],registers[`REG_SPL]}-1; - case (opcode[5:4]) - `INSN_stack_AF: wdata <= registers[`REG_A]; - `INSN_stack_BC: wdata <= registers[`REG_B]; - `INSN_stack_DE: wdata <= registers[`REG_D]; - `INSN_stack_HL: wdata <= registers[`REG_H]; - endcase - end - 1: begin - wr <= 1; - address <= {registers[`REG_SPH],registers[`REG_SPL]}-1; - case (opcode[5:4]) - `INSN_stack_AF: wdata <= registers[`REG_F]; - `INSN_stack_BC: wdata <= registers[`REG_C]; - `INSN_stack_DE: wdata <= registers[`REG_E]; - `INSN_stack_HL: wdata <= registers[`REG_L]; - endcase - end - 2: begin /* TWIDDLE OUR FUCKING THUMBS! */ end - 3: begin - `EXEC_NEWCYCLE; - `EXEC_INC_PC; - end - endcase - end - `INSN_POP_reg: begin /* POP is 12 cycles! */ - case (cycle) - 0: begin - rd <= 1; - address <= {registers[`REG_SPH],registers[`REG_SPL]}; - end - 1: begin - rd <= 1; - address <= {registers[`REG_SPH],registers[`REG_SPL]}; - end - 2: begin - `EXEC_NEWCYCLE; - `EXEC_INC_PC; - end - endcase - end - `INSN_LDH_AC: begin - case (cycle) - 0: begin - address <= {8'hFF,registers[`REG_C]}; - if (opcode[4]) begin // LD A,(C) - rd <= 1; - end else begin - wr <= 1; - wdata <= registers[`REG_A]; - end - end - 1: begin - `EXEC_NEWCYCLE; - `EXEC_INC_PC; - end - endcase - end - `INSN_LDx_AHL: begin - case (cycle) - 0: begin - address <= {registers[`REG_H],registers[`REG_L]}; - if (opcode[3]) begin // LDx A, (HL) - rd <= 1; - end else begin - wr <= 1; - wdata <= registers[`REG_A]; - end - end - 1: begin - `EXEC_NEWCYCLE; - `EXEC_INC_PC; - end - endcase - end - `INSN_ALU8: begin - if ((opcode[2:0] == `INSN_reg_dHL) && (cycle == 0)) begin - // fffffffff fuck your shit, read from (HL) :( - rd <= 1; - address <= {registers[`REG_H], registers[`REG_L]}; - end else begin - `EXEC_NEWCYCLE; - `EXEC_INC_PC; - case (opcode[2:0]) - `INSN_reg_A: tmp <= registers[`REG_A]; - `INSN_reg_B: tmp <= registers[`REG_B]; - `INSN_reg_C: tmp <= registers[`REG_C]; - `INSN_reg_D: tmp <= registers[`REG_D]; - `INSN_reg_E: tmp <= registers[`REG_E]; - `INSN_reg_H: tmp <= registers[`REG_H]; - `INSN_reg_L: tmp <= registers[`REG_L]; - `INSN_reg_dHL: tmp <= rdata; - endcase - end - end - `INSN_NOP: begin - `EXEC_NEWCYCLE; - `EXEC_INC_PC; - end - `INSN_RST: begin - case (cycle) - 0: begin - `EXEC_INC_PC; // This goes FIRST in RST - end - 1: begin - wr <= 1; - address <= {registers[`REG_SPH],registers[`REG_SPL]}-1; - wdata <= registers[`REG_PCH]; - end - 2: begin - wr <= 1; - address <= {registers[`REG_SPH],registers[`REG_SPL]}-2; - wdata <= registers[`REG_PCL]; - end - 3: begin - `EXEC_NEWCYCLE; - {registers[`REG_PCH],registers[`REG_PCL]} <= - {10'b0,opcode[5:3],3'b0}; - end - endcase - end - `INSN_RET: begin - case (cycle) - 0: begin - rd <= 1; - address <= {registers[`REG_SPH],registers[`REG_SPL]}; - end - 1: begin - rd <= 1; - address <= {registers[`REG_SPH],registers[`REG_SPL]} + 1; - end - 2: begin /* twiddle thumbs */ end - 3: begin - `EXEC_NEWCYCLE; - // do NOT increment PC! - end - endcase - end - `INSN_CALL: begin - case (cycle) - 0: begin - `EXEC_INC_PC; - `EXEC_NEXTADDR_PCINC; - rd <= 1; - end - 1: begin - `EXEC_INC_PC; - `EXEC_NEXTADDR_PCINC; - rd <= 1; - end - 2: begin - `EXEC_INC_PC; - end - 3: begin - address <= {registers[`REG_SPH],registers[`REG_SPL]} - 1; - wdata <= registers[`REG_PCH]; - wr <= 1; - end - 4: begin - address <= {registers[`REG_SPH],registers[`REG_SPL]} - 2; - wdata <= registers[`REG_PCL]; - wr <= 1; - end - 5: begin - `EXEC_NEWCYCLE; /* do NOT increment the PC */ - end - endcase - end + `define EXECUTE + `include "allinsns.v" + `undef EXECUTE default: $stop; endcase @@ -430,232 +225,9 @@ module GBZ80Core( end `STATE_WRITEBACK: begin casex (opcode) - `INSN_LD_reg_imm8: - case (cycle) - 0: begin end - 1: case (opcode[5:3]) - `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: begin end - endcase - `INSN_HALT: begin - /* Nothing needs happen here. */ - /* XXX Interrupts needed for HALT. */ - end - `INSN_LD_HL_reg: begin - /* Nothing of interest here */ - end - `INSN_LD_reg_HL: begin - case (cycle) - 0: begin end - 1: begin - case (opcode[5:3]) - `INSN_reg_A: registers[`REG_A] <= tmp; - `INSN_reg_B: registers[`REG_B] <= tmp; - `INSN_reg_C: registers[`REG_C] <= tmp; - `INSN_reg_D: registers[`REG_D] <= tmp; - `INSN_reg_E: registers[`REG_E] <= tmp; - `INSN_reg_H: registers[`REG_H] <= tmp; - `INSN_reg_L: registers[`REG_L] <= tmp; - endcase - end - endcase - end - `INSN_LD_reg_reg: begin - case (opcode[5:3]) - `INSN_reg_A: registers[`REG_A] <= tmp; - `INSN_reg_B: registers[`REG_B] <= tmp; - `INSN_reg_C: registers[`REG_C] <= tmp; - `INSN_reg_D: registers[`REG_D] <= tmp; - `INSN_reg_E: registers[`REG_E] <= tmp; - `INSN_reg_H: registers[`REG_H] <= tmp; - `INSN_reg_L: registers[`REG_L] <= tmp; - endcase - end - `INSN_LD_reg_imm16: begin - case (cycle) - 0: begin /* */ end - 1: begin - case (opcode[5:4]) - `INSN_reg16_BC: registers[`REG_C] <= rdata; - `INSN_reg16_DE: registers[`REG_E] <= rdata; - `INSN_reg16_HL: registers[`REG_L] <= rdata; - `INSN_reg16_SP: registers[`REG_SPL] <= rdata; - endcase - end - 2: begin - case (opcode[5:4]) - `INSN_reg16_BC: registers[`REG_B] <= rdata; - `INSN_reg16_DE: registers[`REG_D] <= rdata; - `INSN_reg16_HL: registers[`REG_H] <= rdata; - `INSN_reg16_SP: registers[`REG_SPH] <= rdata; - endcase - end - endcase - end - `INSN_LD_SP_HL: begin - case (cycle) - 0: registers[`REG_SPH] <= tmp; - 1: registers[`REG_SPL] <= tmp; - endcase - end - `INSN_PUSH_reg: begin /* PUSH is 16 cycles! */ - case (cycle) - 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: {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; - `INSN_stack_BC: registers[`REG_C] <= rdata; - `INSN_stack_DE: registers[`REG_E] <= rdata; - `INSN_stack_HL: registers[`REG_L] <= rdata; - endcase - {registers[`REG_SPH],registers[`REG_SPL]} <= - {registers[`REG_SPH],registers[`REG_SPL]} + 1; - end - 2: begin - case (opcode[5:4]) - `INSN_stack_AF: registers[`REG_A] <= rdata; - `INSN_stack_BC: registers[`REG_B] <= rdata; - `INSN_stack_DE: registers[`REG_D] <= rdata; - `INSN_stack_HL: registers[`REG_H] <= rdata; - endcase - end - endcase - end - `INSN_LDH_AC: begin - case (cycle) - 0: begin /* Type F */ end - 1: if (opcode[4]) - registers[`REG_A] <= rdata; - endcase - end - `INSN_LDx_AHL: begin - case (cycle) - 0: begin /* Type F */ end - 1: begin - if (opcode[3]) - registers[`REG_A] <= rdata; - {registers[`REG_H],registers[`REG_L]} <= - opcode[4] ? // if set, LDD, else LDI - ({registers[`REG_H],registers[`REG_L]} - 1) : - ({registers[`REG_H],registers[`REG_L]} + 1); - end - endcase - end - `INSN_ALU8: begin - if ((opcode[2:0] == `INSN_reg_dHL) && (cycle == 0)) begin - /* Sit on our asses. */ - end else begin /* Actually do the computation! */ - case (opcode[5:3]) - `INSN_alu_ADD: begin - registers[`REG_A] <= - registers[`REG_A] + tmp; - registers[`REG_F] <= - { /* Z */ ((registers[`REG_A] + tmp) == 0) ? 1'b1 : 1'b0, - /* N */ 1'b0, - /* H */ (({1'b0,registers[`REG_A][3:0]} + {1'b0,tmp[3:0]}) >> 4 == 1) ? 1'b1 : 1'b0, - /* C */ (({1'b0,registers[`REG_A]} + {1'b0,tmp}) >> 8 == 1) ? 1'b1 : 1'b0, - registers[`REG_F][3:0] - }; - end - `INSN_alu_ADC: begin - registers[`REG_A] <= - registers[`REG_A] + tmp + {7'b0,registers[`REG_F][4]}; - registers[`REG_F] <= - { /* Z */ ((registers[`REG_A] + tmp + {7'b0,registers[`REG_F][4]}) == 0) ? 1'b1 : 1'b0, - /* N */ 1'b0, - /* H */ (({1'b0,registers[`REG_A][3:0]} + {1'b0,tmp[3:0]} + {4'b0,registers[`REG_F][4]}) >> 4 == 1) ? 1'b1 : 1'b0, - /* C */ (({1'b0,registers[`REG_A]} + {1'b0,tmp} + {8'b0,registers[`REG_F][4]}) >> 8 == 1) ? 1'b1 : 1'b0, - registers[`REG_F][3:0] - }; - end - `INSN_alu_AND: begin - registers[`REG_A] <= - registers[`REG_A] & tmp; - registers[`REG_F] <= - { /* Z */ ((registers[`REG_A] & tmp) == 0) ? 1'b1 : 1'b0, - 3'b010, - registers[`REG_F][3:0] - }; - end - `INSN_alu_OR: begin - registers[`REG_A] <= - registers[`REG_A] | tmp; - registers[`REG_F] <= - { /* Z */ ((registers[`REG_A] | tmp) == 0) ? 1'b1 : 1'b0, - 3'b000, - registers[`REG_F][3:0] - }; - end - `INSN_alu_XOR: begin - registers[`REG_A] <= - registers[`REG_A] ^ tmp; - registers[`REG_F] <= - { /* Z */ ((registers[`REG_A] ^ tmp) == 0) ? 1'b1 : 1'b0, - 3'b000, - registers[`REG_F][3:0] - }; - end - default: - $stop; - endcase - end - end - `INSN_NOP: begin /* NOP! */ end - `INSN_RST: begin - case (cycle) - 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: begin /* type F */ end - 1: registers[`REG_PCL] <= rdata; - 2: registers[`REG_PCH] <= rdata; - 3: begin - {registers[`REG_SPH],registers[`REG_SPL]} <= - {registers[`REG_SPH],registers[`REG_SPL]} + 2; - if (opcode[4]) /* RETI */ - ie <= 1; - end - endcase - end - `INSN_CALL: begin - case (cycle) - 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; - end - endcase - end + `define WRITEBACK + `include "allinsns.v" + `undef WRITEBACK default: $stop; endcase @@ -663,175 +235,3 @@ module GBZ80Core( end endcase endmodule - -`timescale 1ns / 1ps -module ROM( - input [15:0] address, - inout [7:0] data, - input clk, - input wr, rd); - - reg [7:0] rom [2047:0]; - initial $readmemh("rom.hex", rom); - - wire decode = address[15:13] == 0; - wire [7:0] odata = rom[address[11:0]]; - assign data = (rd && decode) ? odata : 8'bzzzzzzzz; - //assign data = rd ? odata : 8'bzzzzzzzz; -endmodule - -module InternalRAM( - input [15:0] address, - inout [7:0] data, - input clk, - input wr, rd); - - reg [7:0] ram [8191:0]; - - wire decode = (address >= 16'hC000) && (address < 16'hFE00); - reg [7:0] odata; - wire idata = data; - assign data = (rd && decode) ? odata : 8'bzzzzzzzz; - - always @(negedge clk) - begin - if (decode && rd) - odata <= ram[address[12:0]]; - else if (decode && wr) - ram[address[12:0]] <= data; - end -endmodule - -module Switches( - input [15:0] address, - inout [7:0] data, - input clk, - input wr, rd, - input [7:0] switches, - output reg [7:0] ledout); - - wire decode = address == 16'hFF51; - reg [7:0] odata; - wire idata = data; - assign data = (rd && decode) ? odata : 8'bzzzzzzzz; - - always @(negedge clk) - begin - if (decode && rd) - odata <= switches; - else if (decode && wr) - ledout <= data; - end -endmodule - -module CoreTop( - input xtal, - input [1:0] switches, - output wire [7:0] leds, - output serio, - output wire [3:0] digits, - output wire [7:0] seven); - - wire clk; - //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] ledout; - assign leds = switches[1] ? (switches[0]?{rd,wr,addr[5:0]}:data[7:0]) - : ledout; - - GBZ80Core core( - .clk(clk), - .busaddress(addr), - .busdata(data), - .buswr(wr), - .busrd(rd)); - - ROM rom( - .address(addr), - .data(data), - .clk(clk), - .wr(wr), - .rd(rd)); - - AddrMon amon( - .addr(addr), - .clk(clk), - .digit(digits), - .out(seven) - ); - - Switches sw( - .address(addr), - .data(data), - .clk(clk), - .wr(wr), - .rd(rd), - .ledout(ledout), - .switches(0) - ); - - UART nouart ( - .clk(clk), - .wr(wr), - .rd(rd), - .addr(addr), - .data(data), - .serial(serio) - ); -endmodule - -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)); - - ROM rom( - .clk(clk), - .address(addr), - .data(data), - .wr(wr), - .rd(rd)); - -// InternalRAM ram( -// .address(addr), -// .data(data), -// .clk(clk), -// .wr(wr), -// .rd(rd)); - -// wire serio; -// UART uart( -// .addr(addr), -// .data(data), -// .clk(clk), -// .wr(wr), -// .rd(rd), -// .serial(serio)); - -// Switches sw( -// .clk(clk), -// .address(addr), -// .data(data), -// .wr(wr), -// .rd(rd), -// .switches(switches), -// .leds(leds)); -endmodule