Usually by overflowing the stack and breaking some other Call/Return.

> -----Original Message-----
> From: Grant Forest [mailto:gforest@NETSPACE.NET.AU]
> Sent: Monday, March 20, 2000 3:04 AM
> To: PICLIST@MITVMA.MIT.EDU
> Subject: How can a CALL break other Code
>
>
> Goodday,
> Have blended a comms and a LCD routine so that I can
> echo back my Hyper terminal character and also display
> it on the LCD.(and it works(big deal I hear you say))
> Now blended a I2C routine and still get the echo OK but
> incorrect character on the LCD.
> The thing that concerns me is, if I am not using interrupts
> nor WDT, and have checked that am not reusing register file
> from another routine, how can a Call mess proven code??
> Could attach the code, but do not want a free ride for the fix,
> just some general points that I must have over looked.
> Tks.
> And Tks for the barking dog answers.
>