SN54HC165,SN74HC165,pdf(8-BIT Parallel-load SHIFT REGISTERS)
The ’HC165 devices are 8-bit parallel-load shift registers that, when clocked, shift the data toward a serial (QH) output. Parallel-in access to each stage is provided by eight individual direct data (A–H) inputs that are enabled by a low level at the shift/load (SH/LD\) input. The ’HC165 devices also feature a clock-inhibit (CLK INH) funcTIon and a complementary serial (QH) output.
Clocking is accomplished by a low-to-high transiTIon of the clock (CLK) input while SH/LD\ is held high and CLK INH is held low. The funcTIons of CLK and CLK INH are interchangeable. Since a low CLK and a low-to-high transiTIon of CLK INH also accomplish clocking, CLK INH should be changed to the high level only while CLK is high.
