CD74HC190E (TEXAS INSTRUMENTS)

The CD74HC190E is a high speed CMOS presettable synchronous BCD decade Up/Down Counter presets the counter to the number on preset data inputs (A-D) is accomplished by a low asynchronous parallel load (LOAD) input. Counting occurs when LOAD is high, count enable (CTEN) is low and the down/up (D/U) input is either high for down counting or low for up counting. The counter is decremented or incremented synchronously with the low-to-high transition of the clock. When an overflow or underflow of the counter occurs, the MAX/MIN output, which is low during counting, goes high and remains high for one clock cycle. This output can be used for look-ahead carry in high-speed cascading. The MAX/MIN output also initiates the ripple clock (RCO) output, which is normally high, goes low and remains low for the low-level portion of the clock pulse.