Can't find error in my schematic with 64 bit RAM

#1 · February 4, 2025, 1:03 pm

Hi. I trying to create schematic with 74XX89 and 74HC193 chips. Counter is working properly, but I can't write any number into RAM. Can you help me and point to my error? Thanks in advance.

RAM

#2 · February 6, 2025, 10:19 am

Hi.

7489 outputs are open collector, so you need pullup resistors or connect to led cathode.
Also note that WE pin is active low.

#3 · February 6, 2025, 1:55 pm

Hello. Thank you for the reply. I change the scheme according to your recomendation and now everything working as intended.

RAM

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