Re: RAM8 Script test pattern

Posted by cadet1620 on
URL: http://nand2tetris-questions-and-answers-forum.52.s1.nabble.com/RAM8-Script-test-pattern-tp4026159p4026160.html

gs99 wrote

(1) What is the value of doing tick output?  We need only the tock output, correct?
I tried this format which seems to work:

It suppose the tick output might be useful for some sort of debugging, but I think of the clock as an event. In the real world the clock event occurs and the synchronous logic updates its output, then the combinational logic updates its value in a very noisy, glitchy, way and eventually settles to a stable value sometime before the next clock event.This settling time limits how fast the clock can run. The values between clock events aren't relevant.

(2) What's the purpose of lines in this (different) format, that first appears in time 8?
set address 1,
eval,                      
output;

The input side of RAM is synchronous--the input only changes the RAM's data when a clock occurs. The output side is asynchronous--whenever the address changes, the output data changes.

The tick/tocks are testing the input side, the evals are testing the output addressing.

--Mark