part-03. ALU+Registers+DATA-Memory

In this forum, we're going to build/design, together, a fully programmable computer, "bit by bit".
That means, that everyone can participate.
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Hans Cadans
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Joined: Thu Apr 24, 2014 12:30 pm

part-03. ALU+Registers+DATA-Memory

Post by Hans Cadans »

Hi everyone,

In this topic, I will expand the former topics with DATA-Memory.
Because I've used a 16-bits Address-Bus, you can apply 64 K Memory.

I've divided Memory in 16 "cards". Each card consists of 4K. and has
it's own start-address. For 4K Memory, you need 12 bits (b11-b0),
so the remaining bits (b15-b12) are used for selection of a card.

Each card has it's own address-register and a 12-bits Full-Adder.
With these components you can use two address-methods,
absolute- and indexed addressing.
Two examples are given in the attached file.

This is the last example, in which you have to manually execute
all the buttons. Next time I will present you the Control-Unit.
This unit will take care of most actions.
In the meantime you can (have to) use the buttons,
this will help you to understand the Control-Unit.

Hans Cadans
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Part-03.CircuitProject
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