Proteus VSM and DS1307

[bryan]

Spent days trying to get the code for a simple RTC using a 1307 and a 18f2620 to work properly in MpLab c18 using Proteus as the debugger.

No matter what I tried I could not get it to display the updated variables in the watch window as the 1307 ticked away. I did not have the 1307 on hand so I was doing it all in Proteus.

I stumbled upon a post that one needs to change the pullup resistors to the 1307 from analog to digital. Did so and it now works. Why digital vs analog pullups to the DS1307 makes a difference in Proteus I don't know. But thought i would pass this on.

 

[be80be]

It's a clock tick tock it's ticking out 10101010101010101 it's a digital clock.

But it is kind of dumb that it would make a difference a pullup is just a pullup to VDD