FCXDEF_STEP
if (le32_to_cpu(pstep->cnt) <= FCXDEF_STEP)
n_begin = le32_to_cpu(pstep->cnt) - FCXDEF_STEP + 1;
array_idx = (i - 1) % FCXDEF_STEP;
btc->ctrl.ctrl.trace_step = FCXDEF_STEP;