74HC/HCT166 8-bit parallel-in/serial-out shift register
The Philips 74HC/HCT166 is an 8-bit shift register designed for synchronous parallel-to-serial applications. It features a fully synchronous serial or parallel data entry selected by an active LOW parallel enable (PE) input. The device includes a clock enable input for a 'do nothing' mode and an asynchronous master reset to clear the register.
| Number of bits | 8-bit |
|---|---|
| Technology | high-speed Si-gate CMOS |
| Propagation delay (CP to Q7, HC) | 15 ns (typ) |
| Propagation delay (MR to Q7, HC) | 14 ns (typ) |
Parallel data is entered when the PE input is LOW, requiring a set-up time prior to the LOW-to-HIGH clock transition.
When PE is HIGH, data enters from the serial input (Ds) and shifts right with each positive-going clock transition.
A LOW on the master reset (MR) input overrides all other inputs and clears the register asynchronously.