core/insn_alu_a.v

   1 `define INSN_alu_RLCA           3'b000
   2 `define INSN_alu_RRCA           3'b001
   3 `define INSN_alu_RLA            3'b010
   4 `define INSN_alu_RRA            3'b011
   5 `define INSN_alu_DAA            3'b100
   6 `define INSN_alu_CPL            3'b101
   7 `define INSN_alu_SCF            3'b110
   8 `define INSN_alu_CCF            3'b111
   9
  10 `define INSN_ALU_A              9'b000xxx111
  11
  12 `ifdef EXECUTE
  13         `INSN_ALU_A: begin
  14                 `EXEC_NEWCYCLE
  15                 `EXEC_INC_PC
  16         end
  17 `endif
  18
  19 `ifdef WRITEBACK
  20         `INSN_ALU_A: begin
  21                 case(opcode[5:3])
  22                 `INSN_alu_RLCA: begin
  23                         `_A <= {`_A[6:0],`_A[7]};
  24                         `_F <= {`_F[7:5],`_A[7],`_F[3:0]};
  25                 end
  26                 `INSN_alu_RRCA: begin
  27                         `_A <= {`_A[0],`_A[7:1]};
  28                         `_F <= {`_F[7:5],`_A[0],`_F[3:0]};
  29                 end
  30                 `INSN_alu_RLA: begin
  31                         `_A <= {`_A[6:0],`_F[4]};
  32                         `_F <= {`_F[7:5],`_A[7],`_F[3:0]};
  33                 end
  34                 `INSN_alu_RRA: begin
  35                         `_A <= {`_F[4],`_A[7:1]};
  36                         `_F <= {`_F[7:5],`_A[0],`_F[3:0]};
  37                 end
  38                 `INSN_alu_CPL: begin
  39                         `_A <= ~`_A;
  40                         `_F <= {`_F[7],1'b1,1'b1,`_F[4:0]};
  41                 end
  42                 `INSN_alu_SCF: begin
  43                         `_F <= {`_F[7:5],1'b1,`_F[3:0]};
  44                 end
  45                 `INSN_alu_CCF: begin
  46                         `_F <= {`_F[7:5],~`_F[4],`_F[3:0]};
  47                 end
  48                 endcase
  49         end
  50 `endif