RE: [avr-gcc-list] INTERRUPT v. SIGNAL problem

[Dean Ferreyra]

John,

I believe your problem is that INTERRUPT re-enables interrupts in the
preamble, before your code reaches your read of UDR, causing the processor
to interrupt again and again.  If you want to re-enable interrupts in your
ISR, you can use SIGNAL, read from the UDR, and only then re-enable
interrupts yourself.

Dean

-----Original Message-----
From: address@hidden [mailto:address@hidden
Behalf Of Borchardt, John Joseph (UMC-Student)
Sent: Tuesday, April 23, 2002 12:23 PM
To: address@hidden
Subject: [avr-gcc-list] INTERRUPT v. SIGNAL problem


Hi,

I'm developing a data transmission protocol using the
2313 UART interrupts, and I'm experiencing a strange
problem.  When I change SIGNAL(SIG_UART_RECV){ ... } to
INTERRUPT(SIG_UART_RECV){ ... }, the isr will not be
called.  Timer and external interrupts are disabled,
and only the UART transmit complete and receive complete
are enabled.  The first thing the SIG_UART_RECV isr does
is to read the UDR, clearing the RXC flag.  The second
thing the isr does is to put a pin high for debugging
purposes.  Everything seems to work fine with SIGNAL,
but not INTERRUPT.  Does anyone know why I'm experiencing
this problem?

Thanks in advance for your help.

-John Borchardt
address@hidden
avr-gcc-list at http://avr1.org

avr-gcc-list at http://avr1.org