Check my stopwatch [multisim]

Discussion in 'Homework Help' started by eastmus, Apr 3, 2009.

1. eastmus Thread Starter New Member

Dec 28, 2008
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0
Hello I made a stopwatch and it counts very nicely, the only problem is that it starts and resets (= the reset button) at 8 (instead of 0). Now this assignment is overdue and the teacher couldnt even help me with this problem. Just curious if someone here can ?
This is the stopwatch in its whole, as you can see the 8 8 8 8 digits, they are supposed to be 0 (= problem!). They start at 8, then actually starts counting 0 1 2 3 4 5 6 7 8 9.

This is the 6 counter, it counts 0 1 2 3 4 5 then resets to 0. The AND gate together with the NOT gates determine at which binary digit to reset. You can read it from the logic analyzer 0110 = 6.

This is an ordinary SR-Latch which works as a toggle D-Latch
http://en.wikipedia.org/wiki/Latch_(electronic)#Gated_D-latch

http://fate.bloodservers.com/stopwatch.zip

if anyone could come up with a reason why or how to fix the start at 0, i'd really appreciate it. Thanks