Fix ld [] and ld []

[fpgaboy.git] / insn_ldm16_a.v

diff --git a/insn_ldm16_a.v b/insn_ldm16_a.v
new file mode 100644 (file)
index 0000000..d8356f7
--- /dev/null
+++ b/insn_ldm16_a.v
@@ -0,0 +1,37 @@
+// 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
+