Condition_Check.v

`include "settings.h"

module Condition_Check
(
    input  [3:0] condition,
    input  [3:0] status_register,
    output reg   condition_state
);

  wire Z = status_register[3];
  wire C = status_register[2];
  wire N = status_register[1];
  wire V = status_register[0];

  parameter[3:0] EQ = 4'd0, NE = 4'd1, CS_HS = 4'd2, CC_LO = 4'd3, MI = 4'd4,
    PL = 4'd5, VS = 4'd6, VC = 4'd7, HI = 4'd8, LS = 4'd9, GE = 4'd10, LT = 4'd11,
    GT = 4'd12, LE = 4'd13, AL = 4'd14;

    always @*
      case(condition)
        EQ:    condition_state = Z;
        NE:    condition_state = ~Z;
        CS_HS: condition_state = C;
        CC_LO: condition_state = ~C;
        MI:    condition_state = N;
        PL:    condition_state = ~N;
        VS:    condition_state = V;
        VC:    condition_state = ~V;
        HI:    condition_state = C & ~Z;
        LS:    condition_state = ~C & Z;
        GE:    condition_state = (N & V) | (~N & ~V);
        LT:    condition_state = (N & ~V) | (~N & V);
        GT:    condition_state = ~Z & ((N & V) | (~N & ~V));
        LE:    condition_state = Z & ((N & ~V) | (~N & V));
        AL:    condition_state = 1'b1;
      endcase

endmodule