shift register - serial to parallel

Thread Starter


Joined Feb 13, 2012
Hi guys

I will need to use 2 or 3 serial to parallel shift registers, I have never use them before, and there is something I am not sure about.

M74HC595 - Page 3
HCF4094 - Page 3

These two seem to do what I want, I want to be able to daisy train them together. In the datasheet, one say STROBE and the other one say SCK (STORAGE CLOCK INPUT). These two look the same to me, but are they the same?

Thanks guys


Joined Oct 2, 2009
74HC595 has SCK and RCK
SCK - is the clock used to shift the serial register SR
RCK - is a clock used to transfer the output of the SR into the output register. Data is latched on the rising edge of RCK

4094 has CLOCK and STROBE
CLOCK - is the clock used to shift the SR
STROBE - is used to latch the data into the output register. There is a subtle difference. Data is always transferred when STROBE is HIGH, i.e. the output register is transparent. Data is latched on the FALLING edge of STROBE.