Hello There,

I'm trying to create a 48x4 RAM module using three 16x4 modules. I using logicworks4 to implement the circuit, but am having trouble getting it to function correctly. I have attached an image of what i have thus far. I just can't seem to debug this thing... Any advice or suggestions would be greatly appreciated!

Thanks!

 

The individual RAM IC's should be in the high Z state with OE high. You shouldn't need the OR gates.

 

No, you will not need the OR gates. Tie the data lines together. And tie the address lines together. Then use a decoder to select the /OE lines (ative low outputs). The address lines 0 to 3 are your inputs 1,2,4,8 and the decoder inputs 16,32 (binary).

Dan.

 

You'll also need to have a decoder on the /WE inputs so you can write different data to each memory device.

Regards,
Ifixit