questions about interrupt for CCS:)

Guest · Posted: Thu Jul 29, 2004 11:12 am

Formerly, i am writing assemble code for PIC MCU. When we finish the interrupt handling, such as UART or Timer, we should clear the interrupt flag, such as RCIF and INTF. So when i writing code for CCS, there is only enable_interrupts() and disable_interrupts()-- built in function could be usef for interrupt?

So did i still need to clear the interrupt flag after handling the interupt procession:)

thank you:)

PCM programmer · Joined: 06 Sep 2003 Posts: 21708

Ttelmah · Guest

PCM programmer, has allready posted the answer.
The key 'giveaway', is that one of the options for an interrupt definition, is a flag 'noclear'. If you add this the interrupt is not cleared, otherwise the compiler does it for you.
Beware that the compiler does it at the end of the handler. Hence if events might happen earlier, you might want to use the 'noclear' option, and clear it yourself at the start of the routine, which would allow the flag to be set much earlier, by a repeated event.

Best Wishes