Move the core to core/

[fpgaboy.git] / core / insn_incdec16.v

diff --git a/core/insn_incdec16.v b/core/insn_incdec16.v
new file mode 100644 (file)
index 0000000..95e0d38
--- /dev/null
+++ b/core/insn_incdec16.v
@@ -0,0 +1,31 @@
+`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