NXP Semiconductors 74HC191
The 74HC191 is an asynchronously presettable 4-bit binary up/down counter. It contains four master/slave flip-flops with internal gating and steering logic to provide asynchronous preset and synchronous count-up and count-down operation. This operation overrides the counting function.| Part No. | 74HC191 |
|---|---|
| Datasheet | 74HC191 Download |
| Manufacturer |  NXP Semiconductors |
| Description | Presettable synchronous 4-bit binary up/down counter |
| Buy | Stock & Price |
74HC191 Presettable synchronous 4-bit binary up/down counter Rev. 3 — 3 January 2017 Product data sheet 1. General description Asynchronous parallel load capability permits the counter to be preset to any desired value. Information present on the parallel data inputs (D0 to D3) is loaded into the counter and appears on the outputs when the parallel load (PL) input is LOW. This operation overrides the counting function. Counting is inhibited by a HIGH level on the count enable (CE) input. When CE is LOW internal state changes are initiated synchronously by the LOW-to-HIGH transition of the clock input. The up/down (U/D) input signal determines the direction of counting as indicated in the function table. The CE input may go LOW when the clock is i
