76Views3Replies

Author Options:

A combination of PROM that takes 16 bit as an input address and when combined with multiple PROMs, gives 18 bits output? Answered

Hey I've been working on a project and have hit a road block. I specifically have 16 bits of addressing which gives 65535 possible addresses, I need to use all of these for reading out data in a PROM that has an output of 18 bits per word, per address I guess you could say. The only problem is that I can't find anything like that.. Or haven't searched hard enough?

Now I could probable use multiple PROMs, just feed the same address to each PROM and I would just bring the outputs together as an entire output instead of multiple outputs. What I'm really looking for is a PROM that takes in a 16 bit address for input... But I can't find the right combination to get 18 bits because they come in 8 bit words or 4 bit..

3 Replies

user
steveastroukBest Answer (author)2014-01-23

You won't find an 18bit device. Just use 3, 64K x 8 devices.

Select as Best AnswerUndo Best Answer

user
iceng (author)steveastrouk2014-01-23

What Steve says ... you don't need to use the extra 6 bits

Select as Best AnswerUndo Best Answer

user
Mudbud (author)iceng2014-01-29

Seems like the only way I guess, thanks.

Select as Best AnswerUndo Best Answer