TMR_SHIFT
t0 = (t0 >> TMR_SHIFT) & TMR_MASK;
t1 = (t1 >> TMR_SHIFT) & TMR_MASK;
for (t0 = 0; t0 < TMR_SHIFT; t0++)
counter_timecounter.tc_frequency = 1000000 * (TMR_SHIFT - t0 + 1);
#define tmr_ustolim(n) (((n) + 1) << TMR_SHIFT)
#define tmr_ustolim4m(n) ((n) << TMR_SHIFT)
#define tmr_cnttous(c) ((((c) >> TMR_SHIFT) & TMR_MASK) - 1)
t0 = (t0 >> TMR_SHIFT) & TMR_MASK;
t1 = (t1 >> TMR_SHIFT) & TMR_MASK;