[fpgaboy.git] / core / insn_ldm16_a.v

`define INSN_LD16M_A		9'b0111x1010	// 1111 for ld A, x; 1110 for ld x, A; bit 1 specifies 16m8 or 8m8

// If opcode[4], then ld A, x, else ld x, A
// If opcode[1], then ld 16m8, else ld 8m8

`ifdef EXECUTE
	`INSN_LD16M_A: begin
		case (cycle)
		0:	begin
				`EXEC_INC_PC
				`EXEC_READ(`_PC + 16'h0001)
			end
		1:	begin
				`EXEC_INC_PC			// we only hit here if 16m8
				`EXEC_READ(`_PC + 16'h0001)
			end
		2:	if (opcode[4])	// LD A,x
				`EXEC_READ(({rdata, tmp}))
			else
				`EXEC_WRITE(({rdata, tmp}), `_A)
		3:	begin
				`EXEC_NEWCYCLE
				`EXEC_INC_PC
			end
		endcase
	end
`endif

`ifdef WRITEBACK
	`INSN_LD16M_A: begin
		case (cycle)
		0:	begin end
		1:	tmp <= rdata;
		2:	begin end
		3:	if (opcode[4]) `_A <= rdata;
		endcase
	end
`endif
Commit	Line	Data
e7fe9dc2 JW	1	`define INSN_LD16M_A 9'b0111x1010 // 1111 for ld A, x; 1110 for ld x, A; bit 1 specifies 16m8 or 8m8
e7fe9dc2 JW	2
f9000d73 JW	3	// If opcode[4], then ld A, x, else ld x, A
	4	// If opcode[1], then ld 16m8, else ld 8m8
	5
	6	`ifdef EXECUTE
fe3dc890	7	`INSN_LD16M_A: begin
f9000d73 JW	8	case (cycle)
	9	0: begin
	10	`EXEC_INC_PC
	11	`EXEC_READ(`_PC + 16'h0001)
	12	end
	13	1: begin
	14	`EXEC_INC_PC // we only hit here if 16m8
	15	`EXEC_READ(`_PC + 16'h0001)
	16	end
	17	2: if (opcode[4]) // LD A,x
f6fa1d6e	18	`EXEC_READ(({rdata, tmp}))
f9000d73	19	else
f6fa1d6e	20	`EXEC_WRITE(({rdata, tmp}), `_A)
f9000d73 JW	21	3: begin
	22	`EXEC_NEWCYCLE
	23	`EXEC_INC_PC
	24	end
	25	endcase
	26	end
	27	`endif
	28
	29	`ifdef WRITEBACK
fe3dc890	30	`INSN_LD16M_A: begin
f9000d73	31	case (cycle)
fe3dc890	32	0: begin end
f6fa1d6e JW	33	1: tmp <= rdata;
f6fa1d6e JW	34	2: begin end
f9000d73 JW	35	3: if (opcode[4]) `_A <= rdata;
	36	endcase
	37	end
	38	`endif
	39