![]() |
![]() |
From | Jaap van Ganswijk <ganswijk@xs4all.nl> |
To | Hantzley Tauckoor |
Subject | Re: Seeking for assistance |
I am a student of Computer Science and Engineering at the university of Mauritius and I am working on a mini project on the "Computer System Organisation of The 8080A and The 8085". I am facing some difficulties particularly when memory is concerned.Having 20 Kbyte SRAM*'s is very unusual. If you really need to use three chips (why not one?) then it's best to use 16 Kbyte chips.
I would be very grateful if you could help me in my work. It would be a great asset for me to have the advice of a professional.
I am to devise a memory map for a partcular microprocessor system which has 16 address lines and 8 data lines in the system bus. My major problem is that I'll have to use 1 chip for the ROM( 4 KB ) and 3 chips For the RAM*( equal size each ). I really have no idea how to tackle this problem.
First I'd like to show my idea and later you tell me if its wrong or not. If the system has 16 address lines, then I would get 64 KB for the addresses in the total memory. Now if I substract 4 KB for the ROM, I would have 60 KB for the RAM* and this is to be divided into 3 chips of equal size. So finally I will get 20 KB for each RAM* chips- which I find difficult, if not impossible, to implement. Moreover, I have the constraint that all logic implementations should be done using only NAND* gates or DECODERS.
0000 | ROM |
4000 | RAM0 |
8000 | RAM1 |
c000 | RAM2 |
a15 | a14 | device |
0 | 0 | ROM |
0 | 1 | RAM0 |
1 | 0 | RAM1 |
1 | 1 | RAM2 |
Perhaps you could send me documents on that issue or the title ofIt's probably also explained in 'The art of electronics book'. See ../chipdir/ext/book/tutorial.htm
any reference book where I could get the solution for this problem, or
you could share with me your ideas for this problem.
Moreover, If a total of 16 I/O ports are available, how can these be accessed.Using the in and out instructions...
Goto: | Main | Mirror | About | Author |
Register: | Yourself | Company | ||
Feedback: | Correction | Addition | Question | Forum |
Request quote: | Chips (Deutsch) | Chips (English) | Chips (Nederlands) |