# ROM Memory blocks

Discussion in 'Homework Help' started by Andreea Blaga ت, Sep 4, 2015.

1. ### Andreea Blaga ت Thread Starter New Member

Jun 26, 2015
15
0
Hello,
I am currently studying for my exam, and I got few exercises left. I came across this exercises that I really don't know how to solve neither I found the solution anywhere.
"Design a 64x4 ROM memory block using 3 ROM blocks of 16x4 bits."
I have no idea how to solve this. Does anyone know something about it?
Any help will be much appreciated, thanks in advance.

2. ### WBahn Moderator

Mar 31, 2012
18,079
4,917
How many total bits is your final ROM memory block supposed to have?

How many total bits do the ROM blocks available to construct it contain?

What do the answers to those questions say about the likelihood of success?

3. ### Andreea Blaga ت Thread Starter New Member

Jun 26, 2015
15
0
Well, if I understood well, I need to construct a ROM memory block having 6 inputs and 4 outputs using 3 ROM memories having 4 inputs and 4 outputs. I figure it has something to do with cascading them somehow, but I don't really get it how.

4. ### WBahn Moderator

Mar 31, 2012
18,079
4,917
Again, how many total bits does your final 64x4 bit ROM block need to contain?

Again, how many total bits are available in the three 16x4 bit ROM blocks that are available to you?

This is like saying that you have to use 3 quart milk containers to hold a gallon of milk.

5. ### Andreea Blaga ت Thread Starter New Member

Jun 26, 2015
15
0
Okay, I don't quite get it how this works. How am i supposed to make 3x 4 inputs to 6 inputs and from 3x 4 outputs to 4 outputs? And by input i also mean the number of bits.

6. ### WBahn Moderator

Mar 31, 2012
18,079
4,917
Forget about inputs and outputs for a moment!

If I give you a memory chip and tell you that it is 64x4 bits, how many bits of memory are contained in that block?

Can you answer that question or not?