Quoted message said:It is possible that the register size in these chips is insufficient to represent more than 10
hours? Can any electronics savvy types out there set me straight or suggest a unit without this
problem?
Thinking out loud...
Consider the display around the 10 hour mark, say 09:59:59. A simple possibility is that the 0 in 09
is hardwired. That is, it's wired to display nothing but 0, so the counting is fixed to never go
beyond that. Terribly sloppy engineering if so! Or a bit of cost cutting.
Or, it may be an odd 15 bit register chip of which I'm not aware.
Or, it may be a 16 bit register to count seconds, with 1 bit reserved for something else, so 15 bits
for counting. 2^15=32768 seconds,
32768/60/60 = 9.1 hours. The reserved bit could possibly be used for the wheel spin status. That is,
1 if the wheel is turning, 0 if not.
Or, it may be a 32 bit register with 15 bits for counting and the other 17 required for the other
functions.
Or, it may have a counter for each unit (hrs/mins/secs), 3 counters in total. The 09 needs 4 bits.
But 4 bits allows up to 15 to be displayed. So no reason to be stuck at 09, unless again sloppy
engineering or cost cutting. The mins and secs in a case like this would each need 6 bits. Notice
4+6+6=16, so 3 separate counters would fit in a 16 bit register.
Or, with 3 counters again, the hours use 3 bits, which allows up to 8 hours. Are you sure it doesn't
roll over after 07:59:59?
There are other ways to represent the count, but nothing leaps out at me as an obvious limitation.
Any other engineers out there with ideas?
Doug
