electronic enthusiasts out there!!! internal circuirtry of 74LS189-64-bit RAM

[earlbesario]

hello to all electronic enthusiasts out there!!!

im looking for the internal circuitry and pin configuration of a very rare IC, the 74LS189.....to be used in our project. can somebody please help me look for it...im quite desperate coz the deadline of the project is 2 weeks away.
i cant find it even in the internet...

thanks

 

[Papabravo]

In my 40 plus years in the business I don't think I've ever seen that despite using the part on numerous occasions.

Here is what I imagine.
#1 -- 64 D-type flip-flops
#2 -- A 64 Input to one output multiplexer for the output
#3 -- A one Input to 64 output decoder
#4 -- A clock/enable circuit that clocks either the present output or the present input into each flip-flop.

It's neither elegant, nor efficient but it does perform the function

 

[oticon6]

If you're after some memory pull some cache chips from an old 486. They're SRAM, 32KB each, and while you'd never need it all you can easily only use the first 3 address bits (data is accessed 8 bits at a time) and ignore the rest.

 

[Papabravo]

It's not clear from the original post that the goal is to use a 74LS189 in a circuit. I think it's more likely that he is struggling with a VLSI design class and he needs a clue for implementing a RAM.

Notice once again that the original poster seldom returns.
Notice also that the identical post has occurred on multiple forums.

 

[on1aag]

74ls189

Hi Earlbesario,

Here are the connections of the 74LS189 and the truth table.

on1aag.

 

[muki55]

datasheet 74LS189

hope it will help.

 

[hotwaterwizard]

**broken link removed**

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http://tams-www.informatik.uni-hamburg.de/applets/hades/webdemos/40-memories/40-ram/demo-74189.html

 

[thedoctor07]

somebody help me!!!!!we are having trouble in our class about the 74ls189 ic..we are required to make the INTERNAL CIRCUITRY of it..could anyone help me???pllllzzzz..i nid it ASAP..

 

[mneary]

Of course you need it ASAP. But you're likely to never get a response with large bold messages.

 

[Hero999]

NO !

 

[Jodelyn De Guzman]

any one.. please help me... what is the replacement for 74LS189?? or where can i buy that 74LS189???

 

[Ian Rogers]

**broken link removed**

https://www.utsource.net/74LS189.html?gclid=CNee9-fOrMQCFWEOwwodwAIA9w

How hard is it to google!!!

 

[tunedwolf]

Are these guys all members of the same class, or worse, team in a class? Sheesh!

 

[absf]

Dont think so.... Just look at the date of the OP --- 2008.

 

[tunedwolf]

I'm usually pretty good at spotting such "revivals", but this one escaped