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hneemann / Digital

A digital logic designer and circuit simulator.
GNU General Public License v3.0
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Multiplexed seven segments not updating instantly #729

Closed maltaisn closed 3 years ago

maltaisn commented 3 years ago

I've got a slight issue with multiplexed seven segment displays: even at max frequency, the display is not refreshed the moment the common cathode is driven low. The display is only refreshed when on a particular drawn frame, its cathode happens to be low. With a several digits and at high frequency, cathodes appear low one at a time in random order until all displays are refreshed.

test

At the indicated frequency of 2 MHz I would expect it to be instantaneous. Here's a smaller circuit in case you want to test: circuit.zip

hneemann commented 3 years ago

@maltaisn It is unbelievable that this problem could remain undetected for so long! Thanks for pointing this out!