Atmel 128 manual says: "When an interrupt occurs, the Global Interrupt Enable I-bit is cleared and all interrupts are disabled. The user software can write logic to the I-bit to enable nested interrupts."
My question: does tinyos permit nested interrupts? --- Michael Schippling <[EMAIL PROTECTED]> wrote: > "...execute one more instruction before any pending > interrupt is served." > > Good manual reading catch! > I wonder if there are any nested int handlers in > TOS? > > MS > > Conor Todd wrote: > > >From pages 13 & 14 of the ATMega128 manual, > there are two types of > > interrupts: ones which are triggered and remain > triggered until they are > > enabled and handled, and ones which only remain > triggered as long as the > > trigger signal is present (and which may not > actually have interrupt > > flags). I am doubtful that the second type would > have been chosen for > > such a core functionality as UART. > > > > Another interesting thing to note is that "When > the AVR exits from an > > interrupt, it will always return to the main > program and execute one > > more instruction before any pending interrupt is > served." So maybe that > > one more instruction clears any pending interrupts > before they can be > > served? > > > > - Conor > > > > > > On 7/14/06, *jose m* <[EMAIL PROTECTED] > > <mailto:[EMAIL PROTECTED]>> wrote: > > > > Hello, > > > > Recently, I've made lots and lots of questions > about > > transmitting data by UART port, because I have > this > > bug and cannot solve it (a little more, and > I'll be a > > lunatic). My problem is this: if my system > runs > > several days, one of these days (any one, any > time), > > no more UART transmission is done. The funny > thing: > > the system is still working normally, send and > receive > > radio packets, update internal data, etc, etc. > > Debugging and testing during hours allows me > to > > conclude this: for some reason (hiding to me), > in > > component UARTM, the variable "state" remains > TRUE, > > and calls to UARTM's txByte(<data>) FAILs. > > What can be the misterious reason of this > problem? I > > suspect that the tx interrupt never executes, > but this > > has low probability. If the ATMega128's > interrupts are > > disabled and enabled again, what happens with > the > > interrups signalled when they were disabled? > > > > José > > > > > ------------------------------------------------------- > > async event result_t HPLUART.putDone() { > > bool oldState; > > > > atomic { > > dbg(DBG_UART, "intr: state %d\n", > state); > > oldState = state; > > state = FALSE; > > } > > > > /* Note that the state transition/event > signalling > > is not atomic. > > It is possible, after state has been > set to > > FALSE, that > > someone calls txByte before txDone is > > signalled. The event > > handler therefore may not be able to > transmit. > > Sharing > > the byte level can be very tricky, > unless we > > assure non-preemptiveness > > or have client ids. The UART > implementation is > > non-preemptive, > > but is not assuredly so. -pal*/ > > if (oldState) { > > signal ByteComm.txDone(); > > signal ByteComm.txByteReady(TRUE); > > } > > return SUCCESS; > > } > > > > > ------------------------------------------------------- > > > > > > > > > > > > > ___________________________________________________________ > > 1GB gratis, Antivirus y Antispam > > Correo Yahoo!, el mejor correo web del mundo > > http://correo.yahoo.com.ar > <http://correo.yahoo.com.ar> > > > > > _______________________________________________ > > Tinyos-help mailing list > > [email protected] > > <mailto:[email protected]> > > > https://mail.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help > > > > > > > > > ------------------------------------------------------------------------ > > > > _______________________________________________ > > Tinyos-help mailing list > > [email protected] > > > https://mail.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help > > ____________________________________________________ Esa persona especial te espera en Yahoo! Encuentros. ¡Dejate encontrar! http://ar.encuentros.yahoo.com/ _______________________________________________ Tinyos-help mailing list [email protected] https://mail.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
