DESCRIPTION

The HEF40195B is a fully synchronous edge-triggered 4-bit shift register with a clock input (CP), four synchronous parallel data inputs (P0 to P3), two synchronous serial data inputs (J, K), a synchronous parallel enable input (PE), buffered parallel outputs from all 4-bit positions (O0 to O3), a buffered inverted output from the last bit position (O3) and an overriding asynchronous master reset input (MR).

Each register stage is of a D-type master-slave flip-flop. Operation is synchronous (except for MR) and is edge-triggered on the LOW to HIGH transition of the CP input. When PE is LOW, data are loaded into the register from P0 to P3 on the LOW to HIGH transition of CP. When PE is HIGH, data are shifted into the first register position from J and K and all the data in the register are shifted one position to the right on the LOW to HIGH transition of CP. D-type entry is obtained by interconnecting J and K. When J is HIGH and K is LOW, the first stage is in the toggle mode. When J is LOW and K is HIGH, the first stage is in the hold mode.

A LOW on MR resets all four bit positions (O0 to O3 = LOW, O3 = HIGH) independent of all other input conditions