Addition Loop Error

[davie1_1]

Hi All,

I keep getting an wrong addition total from the folloing loop:

int32 pos_peak;
pos_peak = 0;
for(i=32; i!=0; i--){
pos_peak += 50000;
}

The total should be 1,600,000 but I get 2148283648. Stepping through it I get the correct result but at full speed it's always wrong. Can someone tell me why and how to fix it? Is it the ADDWFC instruction?

Thanks,
David P

[PCM programmer]

Here's a full test program. I tested this with the MPLAB 7.20 simulator
(with UART1 writing to the Output Window), and also with the
PicDem2-Plus board writing to a terminal window on the PC.
Both displayed this:

[Ttelmah]

The 'error' result, is suspiciously close to 2^31 away from the real result (in fact 800000 away from it). If the sum was subtracting not adding, I'd say there was a confusion between a signed/unsigned integer somewhere...

Best Wishes

[davie1_1]

for some reason I added i++ after the loop and now I get the correct answer in full speed. If I remove the i++ it does it again. I don't know why this would be but increment is a single instruction so I'll leave it.

David P