`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 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_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_LD8M_A 8'b111x0000 // 1111 for ld A, x; 1110 for ld x, A; bit 1 specifies 16m8 or 8m8
+`define INSN_LD16M_A 8'b111x1010 // 1111 for ld A, x; 1110 for ld x, A; bit 1 specifies 16m8 or 8m8
+`define INSN_LDBCDE_A 8'b000xx010 // 0000 for BC, 0001 for DE, 1010 for A,(x), 0010 for (x),A
`define INSN_cc_NZ 2'b00
`define INSN_cc_Z 2'b01
`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,
- input irq, input [7:0] jaddr);
+ input irq, input [7:0] jaddr,
+ output reg [1:0] state);
- reg [1:0] state; /* State within this bus cycle (see STATE_*). */
+// reg [1:0] state; /* State within this bus cycle (see STATE_*). */
reg [2:0] cycle; /* Cycle for instructions. */
reg [7:0] registers[11:0];
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)
`define EXECUTE
`include "allinsns.v"
`undef EXECUTE
- `INSN_DI: begin
- `EXEC_NEWCYCLE;
- `EXEC_INC_PC;
- end
- `INSN_EI: begin
- `EXEC_NEWCYCLE;
- `EXEC_INC_PC;
- end
default:
$stop;
endcase