CPU passes CPU.tst test, but fails CPU.external due to outM output

[coykto]

HI!
I used built-in A- and D- Registers. Therefore i used CPU.tst to test my chip.
After i passed that, i wanted to use CPU-external.tst just to double-check everything, but i notice that CPU-external.cmp checks for outM output of my CPU even during A-Instructions. My ALU's output directly goes to the outM, so half of the time there some gibberish going on as i do not control it when MSB of instruction is 0.

When i replaced outM in CPU-external.cmp with ***** during A-instructions i passed that test too. The question is: After all, does my CPU is suppose to be concerned about it's outM output during A-instruction or not? If not, then why are those values in the CPU-external.cmp file?

[cadet1620]

Where did you get your test files? It sounds like you have a really old version of the CPU-external test.

You can get the latest files from
    http:www.nand2tetris.org/projects/05/CPU-external.tst
    http:www.nand2tetris.org/projects/05/CPU-external.cmp

--Mark

[coykto]

Yeah, that's the same ".cmp" file i end up with. And yes mine were too old, i got them from here. Anyway, thanks for an answer!

[cadet1620]

You will want to get the entire set of files from http://www.nand2tetris.org before you start chapters 7-12.  There are lots of updated tests and some new ones, too.

--Mark

[coykto]

Sure. Thank you!