Restart 18F2620

[peterdeco1]

Am I correct that this can be used to cancel a GOSUB? Thank you.

start:
gosub blink
do more stuff here

blink:
if porta.1 = 1 then sound
high porta.0
pause 50
low porta.0
return

sound:
@ POP
make sound on a pin
goto start

[CocaColaKid]

I believe this is correct. I ran into this problem when I switched from a 16F877 to the 18F452. Took a little bit to track it down. The 16F masked my bad coding practice quite well, lol.

[milestag]

Peter, yes I would say that is correct (or at least one way to do it). I suppose there are no hard and fast rules per se, but any Programming 101 professor would surely beat us with a stick for exiting a GOSUB with a GOTO rather than RETURN with a flag set or some other method.

CCK, Same here, I spent MANY hours headscratching over that one. Until I discovered that the processor always reset after exactly the same number of calls to a certain subroutine. Lots of time spent reading the datasheets/forums too. All resulting from poor (untrained) programming practices/bad habits. But learned a LOT in the process. 18F definitely has a few "gotchas" when migrating.

[peterdeco1]

Thank you for the fast replies guys. Are you also saying that if you don't cancel a gosub with a return on the 16F parts, it doesn't matter? I am not in the habit of doing this but, as a quick fix to a program, it would be handy to know. I was told it will eventually cause a stack overflow on any PIC. Thank you. - Peter

[sinoteq]

You could test to disable the Stack reset in the configuration bits, that should prevent the MCU from doing a reset when doing a stack under- or overflow. Simple and easy but be aware that a return later in the code can make stange things. Page 253 in the manual if you want to look CONFIG4L register.

[cerio]

Power supply: 3.6V current peaks of up to 2° and a maxximum voltage drop of 300mV durino transmission burst. Local power source feeds the Q2501 module and the PIC 18f2620.
Connection MCLRE pin – Diode –R 11Kohm – Vcc. I use one breadboard.
Hour we come to the good news: inserted condenser from 0,1 uf. They are some hours that software turn without restart. The strange characters between the PIC and the PC are passings also. Thanks. Perhaps resolved problem