/* adc.c  -  successive approximation A/D converter */#include <math.h>double dac();int u();void adc(x, b, B, R)double x, R;int *b, B;{       int i;       double y, xQ, Q;       Q = R / pow(2, B);                        /* quantization width \(Q=R/2\sp{B}\) */       y = x + Q/2;                              /* rounding */       for (i = 0; i < B; i++)                   /* initialize bit vector */              b[i] = 0;       b[0] = 1 - u(y);                          /* determine MSB */       for (i = 1; i < B; i++) {                 /* loop starts with \(i=1\) */              b[i] = 1;                          /* turn \(i\)th bit ON */              xQ = dac(b, B, R);                 /* compute DAC output */              b[i] = u(y-xQ);                    /* test and correct bit */              }}