The PD4702 is 8-bit up/down counters for an incremental encoder. Two-phase (A, B) incremental input signals are phase-differentiated, and on each signal edge, an up-count is executed if the A phase is leading, or a down-count if the B phase is leading. Eight-bit count data is output in real time. A carry output and borrow output are also provided for counter overflow and underflow. The PD4704 is also available; use of these enables the count width to be extended.