CPU.hdl: Comparison failure, but output pins are correct

[markbrodie]

In testing CPU.hdl, I encounter a comparison failure, but the output pins all match the values in CPU.cmp at that line. Not sure how to proceed ...

Mark

[cadet1620]

markbrodie wrote

In testing CPU.hdl, I encounter a comparison failure, but the output pins all match the values in CPU.cmp at that line. Not sure how to proceed ...

Mark

The Hardware Simulator should be doing a strict text comparison between the .out and .cmp files. You can hit the run and single step buttons to continue the test after the comparison failure. You can then compare the .out and .cmp files outside of the simulator where you can see all of the text.  (There are some tests where the output is too wide to see it all, I can't remember if CPU is one of them.)

If you can't find the difference, please email me your CPU.hdl. I'd like to see if I can reproduce the problem.

--Mark

[markbrodie]

Hi,

It turned out to be the D-register value that was different between the out and cmp files. Not hard to fix. But I am curious as to why the D-register value is included in the comparison and not the A-register.

Thanks,

Mark

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Date: Sat, 26 Jan 2013 20:29:52 -0800
From: [hidden email]
To: [hidden email]
Subject: Re: CPU.hdl: Comparison failure, but output pins are correct

markbrodie wrote

In testing CPU.hdl, I encounter a comparison failure, but the output pins all match the values in CPU.cmp at that line. Not sure how to proceed ...

Mark

The Hardware Simulator should be doing a strict text comparison between the .out and .cmp files. You can hit the run and single step buttons to continue the test after the comparison failure. You can then compare the .out and .cmp files outside of the simulator where you can see all of the text.  (There are some tests where the output is too wide to see it all, I can't remember if CPU is one of them.)

If you can't find the difference, please email me your CPU.hdl. I'd like to see if I can reproduce the problem.

--Mark

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[cadet1620]

markbrodie wrote

It turned out to be the D-register value that was different between the out and cmp files. Not hard to fix. But I am curious as to why the D-register value is included in the comparison and not the A-register.

If you follow the design in the book, the A-register is directly connected to addressM, which is one of the output columns.

--Mark