Author Topic: HY6264 SRAM - CS1/CS2?  (Read 1005 times)

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Offline gmcTopic starter

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HY6264 SRAM - CS1/CS2?
« on: November 08, 2019, 09:28:38 am »
Busy messing around with an Arduino and some of this old school ram.

On the truth table to read/write you put CS1 low and CS2 high.
To power down chip CS2 goes low.

Just curious why they didn't just use a single CS pin. Why the need for CS1 and CS2?

What am I missing?

https://datasheetspdf.com/datasheet/HY6264.html

 

Offline capt bullshot

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Re: HY6264 SRAM - CS1/CS2?
« Reply #1 on: November 08, 2019, 09:32:28 am »

Just curious why they didn't just use a single CS pin. Why the need for CS1 and CS2?
What am I missing?


You're missing nothing. There's no need for a second pin, they've just used a spare package pin to provide you with a second CS pin for your convenience. Sometimes this was used to easily power down and protect battery backed memory from accidental writes when the CPU powers up or down. Saved a gate back then.
Safety devices hinder evolution
 

Offline gmcTopic starter

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Re: HY6264 SRAM - CS1/CS2?
« Reply #2 on: November 08, 2019, 09:34:53 am »
Thanks for the info.  Thought it was odd.

 


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