Re: Confused about CPU-external.cmp

Posted by cadet1620 on
URL: http://nand2tetris-questions-and-answers-forum.52.s1.nabble.com/Confused-about-CPU-external-cmp-tp4032166p4032168.html

You should be looking at CPU.tst/.cmp so that you can see the current D register values. The -external tests are for people who are not using DRegister in their CPU.

Test setups are strange. Because there is no RAM or ROM involved, each individual instruction test sets input values for 'instruction' and 'inM'. The PC does not affect the sequence of instructions fed to the CPU by the test, nor does the A register affect what the inM value is.

--Mark