public ClockDomainCrosser(UInt64 _clock1, UInt64 _clock2, ClockUpdateCB _callback)
{
callback = _callback;
clock1 = _clock1;
clock2 = _clock2;
counter1 = 0;
counter2 = 0;
}
public ClockDomainCrosser(ClockUpdateCB _callback)
{
callback = _callback;
clock1 = 1UL;
clock2 = 1UL;
counter1 = 0UL;
counter2 = 0UL;
}
public ClockDomainCrosser(double ratio, ClockUpdateCB _callback)
{
callback = _callback;
counter1 = 0;
counter2 = 0;
// Compute numerator and denominator for ratio, then pass that to other constructor.
double x = ratio;
const int MAX_ITER = 15;
int i;
int[] ns = new int[MAX_ITER];
int[] ds = new int[MAX_ITER];
double[] zs = new double[MAX_ITER];
ds[0] = 0;
ds[1] = 1;
zs[1] = x;
ns[1] = (int)x;
for (i = 1; i < MAX_ITER - 1; i++)
{
if (Math.Abs(x - (double)ns[i] / (double)ds[i]) < 0.00005)
{
//printf("ANSWER= %u/%d\n",ns[i],ds[i]);
break;
}
//TODO: or, if the answers are the same as the last iteration, stop
zs[i + 1] = 1.0f / (zs[i] - (int)Math.Floor(zs[i])); // 1/(fractional part of z_i)
ds[i + 1] = ds[i] * (int)Math.Floor(zs[i + 1]) + ds[i - 1];
double tmp = x * ds[i + 1];
double tmp2 = tmp - (int)tmp;
ns[i + 1] = tmp2 >= 0.5 ?(int)Math.Ceiling(tmp) : (int)Math.Floor(tmp); // ghetto implementation of a rounding function
//printf("i=%lu, z=%20f n=%5u d=%5u\n",i,zs[i],ns[i],ds[i]);
}
//printf("APPROXIMATION= %u/%d\n",ns[i],ds[i]);
this.clock1 = (ulong)ns[i];
this.clock2 = (ulong)ds[i];
//cout << "CTOR: callback address: " << (uint64_t)(this->callback) << "\t ratio="<<clock1<<"/"<<clock2<< endl;
}
