CPU-how does the inputs and outputs relate to each other?

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CPU-how does the inputs and outputs relate to each other?

horhen
This post was updated on .
im not quite getting what to do.
The supplied "task" in the CPU.hdl seems to be puzzling to me. I don't understand how the inputs of the CPU.hdl affects its output. I would appreciate it if someone could give me a mathematical explanation of the task. By "mathematical" I meant in equation form. e.g. if reset == 1 then out(t) = in(t-1)... thanks.
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Re: CPU-how does the inputs and outputs relate to each other?

cadet1620
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horhen wrote
im not quite getting what to do.
The supplied "task" in the CPU.hdl seems to be puzzling to me. I don't understand how the inputs of the CPU.hdl affects its output. I would appreciate it if someone could give me a mathematical explanation of the task. By "mathematical" I meant in equation form. e.g. if reset == 1 then out(t) = in(t-1)... thanks.
The CPU implementation is described in 5.3.1 and accompanied by an block diagram in figure 5.9. Everything in the diagram, except "decode," is one of the parts that you have built or a supplied part (ARegister and DRegister). The circled C signals are the "control signals" that are connected to the part inputs that are not explicitly shown in the diagram.

For instance, the PC needs to have signals for its load and inc. It's the job of "decode" to generate these signals based on bits in instruction and the ALU's zr and ng.

Starting with figure 5.9 you can develop your own detailed specification. It might look something like:

    AinMux.a = ALU.out
    AinMux.b = instruction
    AinMux.sel = Decode.ain_select

    Areg.in = AinMux.out
    Areg.load = Decode.areg_load

The main challenge is to determine the required logic for the control signals. Think about how the various instructions you used writing the Project 4 programs work.

--Mark
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