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Can 74HC164 output registers be chained?
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Can 74HC164 output registers be chained?

by shobley on Tue Sep 28, 2010 3:29 pm

I have some leftover 74HC164 serial in, parallel out shift registers and I was trying to ascertain if these can be chained together like the 74HC165 input registers can be.

If I were to tie the "last" output of the previous chip as the input to the next chip along, and just keep on clockin' - would this work?

Has anyone done this?

Thanks in advance,
Steve

UPDATE : looks like the 74HC595 would be a better choice - as this can be latched and chained.
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Re: Can 74HC164 output registers be chained?

by adshea on Tue Sep 28, 2010 3:36 pm

Tying Q8 to A and B should work. If you need a Chip Select sort of line just tie Q8 on the first chip to A on the second chip and tie both B's together as a chip select.

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Re: Can 74HC164 output registers be chained?

by richms on Wed Sep 29, 2010 4:33 am

Yeah I did it, and it works fine, but the lack of latch on the 164 meant that I had to have a high side switch on the LEDs I was driving since there was some visible flicker with the clocking. That was when I was using the arduino commands to change ports which were really slow, so it might be ok with direct writes to the registers.

Later on I got a crapload of 595s off ebay which have the latch which meant that write speed was less of an issue.

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