]> Joshua Wise's Git repositories - fpgaboy.git/blobdiff - GBZ80Core.v
Split out more insns
[fpgaboy.git] / GBZ80Core.v
index fef4de29e759bf487cfd2343098d3c040f642ba0..f41805ac3c679aeebded8c8d2014f921fe8931c0 100644 (file)
@@ -90,9 +90,9 @@
 
 module GBZ80Core(
        input clk,
-       output reg [15:0] busaddress = 0,       /* BUS_* is latched on STATE_FETCH. */
+       output reg [15:0] busaddress,   /* BUS_* is latched on STATE_FETCH. */
        inout [7:0] busdata,
-       output reg buswr = 0, output reg busrd = 0,
+       output reg buswr, output reg busrd,
        input irq, input [7:0] jaddr);
        
        reg [1:0] state;                                        /* State within this bus cycle (see STATE_*). */
@@ -112,7 +112,7 @@ module GBZ80Core(
        reg [7:0] buswdata;
        assign busdata = buswr ? buswdata : 8'bzzzzzzzz;
        
-       reg ie = 0, iedelay = 0;
+       reg ie, iedelay;
        
        initial begin
                registers[ 0] <= 0;
@@ -191,213 +191,9 @@ module GBZ80Core(
 `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]}-2;
-                                               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 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]} + 1;
-                                       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_ALU_A: begin
-                               `EXEC_NEWCYCLE;
-                               `EXEC_INC_PC;
-                       end
-                       `INSN_NOP: begin
-                               `EXEC_NEWCYCLE;
-                               `EXEC_INC_PC;
-                       end
+                       `define EXECUTE
+                       `include "allinsns.v"
+                       `undef EXECUTE
                        `INSN_RST: begin
                                case (cycle)
                                0:      begin
@@ -602,255 +398,9 @@ 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:      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_POP_reg: begin    /* POP is 12 cycles! */
-                               case (cycle)
-                               0:      begin end
-                               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
-                                       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
-                                               {registers[`REG_SPH],registers[`REG_SPL]} <=
-                                                       {registers[`REG_SPH],registers[`REG_SPL]} + 2;
-                                       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_SUB: begin
-                                               registers[`REG_A] <=
-                                                       registers[`REG_A] - tmp;
-                                               registers[`REG_F] <=
-                                                       { /* Z */ ((registers[`REG_A] - tmp) == 0) ? 1'b1 : 1'b0,
-                                                         /* N */ 1'b1,
-                                                         /* 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_SBC: 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'b1,
-                                                         /* 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
-                                       `INSN_alu_CP: begin
-                                               registers[`REG_F] <=
-                                                       { /* Z */ ((registers[`REG_A] - tmp) == 0) ? 1'b1 : 1'b0,
-                                                         /* N */ 1'b1,
-                                                         /* 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
-                                       default:
-                                               $stop;
-                                       endcase
-                               end
-                       end
-                       `INSN_ALU_A: begin
-                               case(opcode[5:3])
-                               `INSN_alu_RLCA: begin
-                                       registers[`REG_A] <= {registers[`REG_A][6:0],registers[`REG_A][7]};
-                                       registers[`REG_F] <= {registers[`REG_F][7:5],registers[`REG_A][7],registers[`REG_F][3:0]};
-                               end
-                               `INSN_alu_RRCA: begin
-                                       registers[`REG_A] <= {registers[`REG_A][0],registers[`REG_A][7:1]};
-                                       registers[`REG_F] <= {registers[`REG_F][7:5],registers[`REG_A][0],registers[`REG_F][3:0]};
-                               end
-                               `INSN_alu_RLA: begin
-                                       registers[`REG_A] <= {registers[`REG_A][6:0],registers[`REG_F][4]};
-                                       registers[`REG_F] <= {registers[`REG_F][7:5],registers[`REG_A][7],registers[`REG_F][3:0]};
-                               end
-                               `INSN_alu_RRA: begin
-                                       registers[`REG_A] <= {registers[`REG_A][4],registers[`REG_A][7:1]};
-                                       registers[`REG_F] <= {registers[`REG_F][7:5],registers[`REG_A][0],registers[`REG_F][3:0]};
-                               end
-                               `INSN_alu_CPL: begin
-                                       registers[`REG_A] <= ~registers[`REG_A];
-                                       registers[`REG_F] <= {registers[`REG_F][7],1'b1,1'b1,registers[`REG_F][4:0]};
-                               end
-                               `INSN_alu_SCF: begin
-                                       registers[`REG_F] <= {registers[`REG_F][7:5],1'b1,registers[`REG_F][3:0]};
-                               end
-                               `INSN_alu_CCF: begin
-                                       registers[`REG_F] <= {registers[`REG_F][7:5],~registers[`REG_F][4],registers[`REG_F][3:0]};
-                               end
-                               endcase
-                       end
-                       `INSN_NOP: begin /* NOP! */ end
+                       `define WRITEBACK
+                       `include "allinsns.v"
+                       `undef WRITEBACK
                        `INSN_RST: begin
                                case (cycle)
                                0:      begin /* type F */ end
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