[fpgaboy.git] / core / insn_incdec16.v

`define INSN_INCDEC16		9'b000xxx011

`ifdef EXECUTE
	`INSN_INCDEC16: begin
		case (cycle)
		0:	case (opcode[5:4])
			`INSN_reg16_BC:	{tmp,tmp2} <= `_BC;
			`INSN_reg16_DE:	{tmp,tmp2} <= `_DE;
			`INSN_reg16_HL:	{tmp,tmp2} <= `_HL;
			`INSN_reg16_SP:	{tmp,tmp2} <= `_SP;
			endcase
		1:	begin
				`EXEC_INC_PC
				`EXEC_NEWCYCLE
			end
		endcase
	end
`endif

`ifdef WRITEBACK
	`INSN_INCDEC16: begin
		case (cycle)
		0:	{tmp,tmp2} <= {tmp,tmp2} +
				(opcode[3] ? 16'hFFFF : 16'h0001);
		1:	case (opcode[5:4])
			`INSN_reg16_BC:	`_BC <= {tmp,tmp2};
			`INSN_reg16_DE:	`_DE <= {tmp,tmp2};
			`INSN_reg16_HL:	`_HL <= {tmp,tmp2};
			`INSN_reg16_SP:	`_SP <= {tmp,tmp2};
			endcase
		endcase
	end
`endif
Commit	Line	Data
e7fe9dc2 JW	1	`define INSN_INCDEC16 9'b000xxx011
e7fe9dc2 JW	2
df770340 JW	3	`ifdef EXECUTE
	4	`INSN_INCDEC16: begin
	5	case (cycle)
5c33c5c0 JW	6	0: case (opcode[5:4])
	7	`INSN_reg16_BC: {tmp,tmp2} <= `_BC;
	8	`INSN_reg16_DE: {tmp,tmp2} <= `_DE;
	9	`INSN_reg16_HL: {tmp,tmp2} <= `_HL;
	10	`INSN_reg16_SP: {tmp,tmp2} <= `_SP;
	11	endcase
df770340	12	1: begin
5c33c5c0 JW	13	`EXEC_INC_PC
5c33c5c0 JW	14	`EXEC_NEWCYCLE
df770340 JW	15	end
	16	endcase
	17	end
	18	`endif
	19
	20	`ifdef WRITEBACK
	21	`INSN_INCDEC16: begin
	22	case (cycle)
	23	0: {tmp,tmp2} <= {tmp,tmp2} +
	24	(opcode[3] ? 16'hFFFF : 16'h0001);
5c33c5c0 JW	25	1: case (opcode[5:4])
	26	`INSN_reg16_BC: `_BC <= {tmp,tmp2};
	27	`INSN_reg16_DE: `_DE <= {tmp,tmp2};
	28	`INSN_reg16_HL: `_HL <= {tmp,tmp2};
	29	`INSN_reg16_SP: `_SP <= {tmp,tmp2};
	30	endcase
df770340 JW	31	endcase
	32	end
	33	`endif