Philips 74F191
The 74F191 is a 4-bit binary counter. It contains four edge-triggered master/slave flip-flops with internal gating and steering logic to provide asynchronous preset and synchronous count-up and count-down operations. This operation overrides the counting function.| Part No. | 74F191 |
|---|---|
| Datasheet | 74F191 Download |
| Manufacturer |  Philips |
| Description | Up/down binary counter |
| Buy | Stock & Price |
FEATURES
● High speed –125MHz typical fMAX● Synchronous, reversible counting
● 4-Bit binary
● Asynchronous parallel load capability
● Cascadable without external logic
● Single up/down control input
DESCRIPTION
The 74F191 is a 4-bit binary counter. Asynchronous parallel load capability permits the counter to be preset to any desired number. Information present on the parallel data inputs (D0 - 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. Overflow/underflow indications are provided by two types of outputs, the Terminal Count (TC) and Ripple Clock (RC). The TC output is normally Low and goes High when: 1) the count reaches zero in the countdown mode or 2) reaches “15” in the count up mode. The TC output will remain High until a state change occurs, either by counting or presetting, or until U/D is changed.
