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Hello All! I'm trying to write a simple interrupt routine for a external interrupt source (EINT0) for a LPC2106. As there's no selection between level or edge-triggered interrupts, I want to to wait until there's a logic 1 on the EINTx pin to clear the intrrupt on the VIC to not count a long strobe as several different interrupts. This goes along with the LPC2106 user's manual, as on page 40 it says that to clear a pending intrerrupt on EINTx I have to wait until there's a high level on the pin, so I REALLY want to wait until a logic 1 is present. But how do I do that? I already tried a code like this in my interrupt handler: (defines based on freeRTOS) while( (GPIO0_IOPIN & (0x01<<16)) == 0 ); SCB_EXTINT |= 0x01; VICVectAddr = serCLEAR_VIC_INTERRUPT; If I remove the while() loop; I get several interrupts, as expected. But if I leave the loop, after the first strobe on the pin, the processor gets stuck. Can I use the IOPIN register to read the current logic level on the pin? I think so, by reading the register description on page 81 of the UM. Thanks a lot -- Leonardo Pereira Santos Engenheiro de Projetos |
LPC2106 external interrupts
Started by ●March 15, 2005
Reply by ●March 15, 20052005-03-15
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Easy - Use a LPC23xx series chip! I don't know why they did level interrupts on the LPC21xx series (easier to impliment?). I have never used a level interrupt in a micro controller. You could use a D flipflop (Q Bar output) and a port line to reset it. The line will be high again before you reenable the intterupt. Thats what I was planning in a previous project. Fortunalty it has been delayed until now and I am planning on using a LPC 23xx solution and an edge triggered interrupt. Owen Mooney Hello All! I'm trying to write a simple interrupt routine for a external interrupt source (EINT0) for a LPC2106. As there's no selection between level or edge-triggered interrupts, I want to to wait until there's a logic 1 on the EINTx pin to clear the intrrupt on the VIC to not count a long strobe as several different interrupts. This goes along with the LPC2106 user's manual, as on page 40 it says that to clear a pending intrerrupt on EINTx I have to wait until there's a high level on the pin, so I REALLY want to wait until a logic 1 is present. But how do I do that? I already tried a code like this in my interrupt handler: |
Reply by ●March 17, 20052005-03-17
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Hi You can not read the port via GPIO when the port is defined as External Int. You hav to try clearing the bit until it is accepted. I do this while( SCB_EXTINT & 0x01 ) { SCB_EXTINT = 0x01; } VICVectAddr = serCLEAR_VIC_INTERRUPT; best regards John Noergaard --- In , Leonardo Santos <lsantos@p...> wrote: > Hello All! > I'm trying to write a simple interrupt routine for a external interrupt > source (EINT0) for a LPC2106. As there's no selection between level or > edge-triggered interrupts, I want to to wait until there's a logic 1 on the > EINTx pin to clear the intrrupt on the VIC to not count a long strobe as > several different interrupts. This goes along with the LPC2106 user's manual, > as on page 40 it says that to clear a pending intrerrupt on EINTx I have to > wait until there's a high level on the pin, so I REALLY want to wait until a > logic 1 is present. But how do I do that? > I already tried a code like this in my interrupt handler: > > (defines based on freeRTOS) > > while( (GPIO0_IOPIN & (0x01<<16)) == 0 ); > SCB_EXTINT |= 0x01; > VICVectAddr = serCLEAR_VIC_INTERRUPT; > > If I remove the while() loop; I get several interrupts, as expected. But if I > leave the loop, after the first strobe on the pin, the processor gets stuck. > Can I use the IOPIN register to read the current logic level on the pin? I > think so, by reading the register description on page 81 of the UM. > > Thanks a lot > > -- > > Leonardo Pereira Santos > Engenheiro de Projetos |
