/*---------------------------------------------------------
 *
 * Multi-fault Fault Simulator (C-RAM)
 *
 */

#include <cram.h>
#include"fault.h"

/* generic one output gate */
/* with initialization to 0 and provision for stuck at faults */
class gate
{
    private:
    int serialNumber;

        public:
    cboolean output;
    static int nextSerial;

        gate()
    {
        output.zero();
        serialNumber = nextSerial++;
    }

    cboolean &update(const cboolean &newval)
    {
        output = newval && PEid.extractBit(serialNumber);
        return (output);
    }

};

/* two input nand gate */
class nand2:public gate
{
    public:
    cboolean &e(const cboolean &in1, const cboolean &in2)
    {
        return update(!(in1 && in2));
    }
};

int gate::nextSerial = 0;



nand2 s, r, g1, g2, g3, g4, g5, g6, g7, g8, g9, g10, g11, g12,
      g13, g14, g15;

/* a self-evaluating netlist */
cboolean &net(cboolean in1, cboolean in2, cboolean in3, cboolean in4, cboolean in5, cboolean in6, cboolean in7, cboolean in8, cboolean reset)
{
// tree of combinational logic followed by an RS flipflop
    (void) g15.e(
                    g13.e(g9.e(g1.e(in1, in2), g2.e(in3, in4)),
                          g10.e(g3.e(in5, in6), g4.e(in7, in8))),
                    g14.e(g11.e(g5.e(in1, in2), g6.e(in3, in4)),
                          g12.e(g7.e(in5, in6), g8.e(in7, in8))));
    (void) r.e(s.e(g15.output, r.output), reset);
    return (r.e(s.e(g15.output, r.output), reset));
}


/* Determine if the test vector detects all faults */
boolean faultSim()
{
    cboolean passed;
    cboolean answer1, answer2, answer3;
    cboolean result1, result2, result3;
    cboolean correctAnswer;
    cboolean k0, k1;            // constants

    cuint lastTestCaseNumber(20, UNALIGNED);

/* identify the PE simulating no faults */
  lastTestCaseNumber = 1 << gate::nextSerial - 1;
    correctAnswer = PEid == lastTestCaseNumber;
    k0.zero();
    k1 = !k0;

    result1 = net(k1, k0, k1, k0, k1, k0, k1, k0, k1);
    result2 = net(k0, k1, k0, k1, k0, k1, k0, k1, k0);
    result3 = net(k1, k0, k1, k0, k1, k1, k1, k0, k1);

    answer1.broadcast(correctAnswer, result1);
    answer2.broadcast(correctAnswer, result2);
    answer3.broadcast(correctAnswer, result3);

    passed = (result1 != answer1) || (result2 != answer2) ||
          (result3 != answer3);

/* the PE holding the correct answer will never successfully */
/* detect a fault, so ignore it */
    passed = passed || correctAnswer;

    return (candScalar(passed));
}