On Tue, Jul 22, 2008 at 4:05 PM, Kirak, Hong <[EMAIL PROTECTED]> wrote:
> Hi guys, > > > > I'm making a communication system using UART0, and it seems UART overrun > error frequently happens. > Also note that if you are using the MSP430, the interrupt signal handler clears the OE bit (overrun error indicator) prior to handing off the signal to any code wired in. So any down stream code won't see the overrun. > > > I read some document about UART, and it says if UART interrupt is not fast > enough, that error occurs. > > > > I'm doing nothing but a UART transmission, so I'm suspecting CPU is doing > something else when UART is transmitting. > That is probably what is happening. What speed are you running at? If you are at 115200 I would suggest backing off to 57600 and if that works then the conclusion that the interrupt service routine is too long is probably reasonable. > > > And I guess it's related to atomic section or something like that, so my > questions are following. > > > > 1. Is atomic section turn off entire interrupt? > atomic sections disable interrupts by turning off the GIE (global interrupt enable), at least that is what happens on the MSP430. > 2. If a interrupt handler is defined TOSH_SIGNAL, not > TOSH_INTERRUPT, is it true that interrupt can not be nested? What happens > TOSH_SIGNAL interrupt has occurred during another TOSH_SIGNAL interrupt is > on handling? > The default interrupt behaviour on the MSP430 is interrupts are not nested. I've left it that way because I don't need any more problems to solve right now. The little bit I looked at, nesting interrupts on the MSP430 looks tricky. 3. I can see frequent error packets through UART, is it possible > reduce error rate through UART? > > (Down to ideal error rate of UART with specific baud rate) > > > First is to understand the problem. What is causing the errors? Then reduce the errors by fixing things. Most likely it is the interrupt service time. eric > Any advice will be highly appreciated. Thanks. > > > > With Kind Regards, > > Kirak > > _______________________________________________ > Tinyos-help mailing list > [email protected] > https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help > -- Eric B. Decker Senior (over 50 :-) Researcher Autonomous Systems Lab Jack Baskin School of Engineering UCSC
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