Hello all, I am trying to use a falling edge GPIO interrupt on P0.11.

I setup the pin as an input and have tested it as such and it seems to
work fine.

PINSEL0 &= 0xFF3FFFFF;
PINMODE0 &= 0xFFBFFFFF;

// Set the pins to be GPIO inputs.
FIO0DIR1 &= 0xF7; // 11110111

I also setup the IO0_INT_EN_F to enable the falling edge interrupt.

IO0_INT_EN_F &= 0x800;

Also then load and enable the VIC channel. I see in the docs that
EINT3 - channel 17 - is shared with GPIO interrupts.

VICVectAddr17 = (uint32)eint3_int;
VICIntEnable = (1 << 17);

Inside eint3_int I toggle an LED, clear the interrupt flag, and clear
the VIC address register.

When I put a signal on P0.11 I never get any interrupt out of it.
Signal looks good, 100us square pulse.

I threw a test bit of code to set the soft int in another timer
routine - when I have a breakpoint in my ISR I repeatedly hit it as
expected, but never with just the signal.

I am wondering if anyone else has used a GPIO interrupt in this
fashion and had success? I can't find anything relating to this
problem with the LPC23xx - but there are some issues for the other
LPC21/22xx series having to do with order, etc. Could one of these
things be an issue here as well?

Thanks in advance for any advice on this issue.

Sean
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Without having carefully looked at all your 'numbers': one quick
observation:

Make sure to enable fast GPIO:

SCS |= 1; // Enable FAST GPIO

~ Paul

From: l... [mailto:l...] On Behalf Of
grady_sean
Sent: Tuesday, April 22, 2008 9:06 AM
To: l...
Subject: [lpc2000] LPC2364 GPIO Interrupt Problem

Hello all, I am trying to use a falling edge GPIO interrupt on P0.11.

I setup the pin as an input and have tested it as such and it seems to
work fine.

PINSEL0 &= 0xFF3FFFFF;
PINMODE0 &= 0xFFBFFFFF;

// Set the pins to be GPIO inputs.
FIO0DIR1 &= 0xF7; // 11110111

I also setup the IO0_INT_EN_F to enable the falling edge interrupt.

IO0_INT_EN_F &= 0x800;

Also then load and enable the VIC channel. I see in the docs that
EINT3 - channel 17 - is shared with GPIO interrupts.

VICVectAddr17 = (uint32)eint3_int;
VICIntEnable = (1 << 17);

Inside eint3_int I toggle an LED, clear the interrupt flag, and clear
the VIC address register.

When I put a signal on P0.11 I never get any interrupt out of it.
Signal looks good, 100us square pulse.

I threw a test bit of code to set the soft int in another timer
routine - when I have a breakpoint in my ISR I repeatedly hit it as
expected, but never with just the signal.

I am wondering if anyone else has used a GPIO interrupt in this
fashion and had success? I can't find anything relating to this
problem with the LPC23xx - but there are some issues for the other
LPC21/22xx series having to do with order, etc. Could one of these
things be an issue here as well?

Thanks in advance for any advice on this issue.

Sean


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--- In l..., "Paul Claessen" wrote:
>
> Without having carefully looked at all your 'numbers': one quick
> observation:
>
>
>
> Make sure to enable fast GPIO:
>
>
>
> SCS |= 1; // Enable FAST GPIO
>
>
>
> ~ Paul

Hello, thank you for your suggestion. We are indeed setting the
'GPIOM' but for Fast I/O. I verified this after reading your post by
looking at the System Control & Status reg settings through the debugger.

Also, if I just try to use that pin as a GPIO Input it does seem to
work fine.

Thanks again for your time, it is much appreciated.
Start a New Thread

If you enable falling-edge, you should
IO0_INT_EN_F |= 0x800;
below line doesn't do any good.

> IO0_INT_EN_F &= 0x800;

Tom
--- In l..., "grady_sean" wrote:
>
> Hello all, I am trying to use a falling edge GPIO interrupt on P0.11.
>
> I setup the pin as an input and have tested it as such and it seems to
> work fine.
>
> PINSEL0 &= 0xFF3FFFFF;
> PINMODE0 &= 0xFFBFFFFF;
>
> // Set the pins to be GPIO inputs.
> FIO0DIR1 &= 0xF7; // 11110111
>
> I also setup the IO0_INT_EN_F to enable the falling edge interrupt.
>
> IO0_INT_EN_F &= 0x800;
>
> Also then load and enable the VIC channel. I see in the docs that
> EINT3 - channel 17 - is shared with GPIO interrupts.
>
> VICVectAddr17 = (uint32)eint3_int;
> VICIntEnable = (1 << 17);
>
> Inside eint3_int I toggle an LED, clear the interrupt flag, and clear
> the VIC address register.
>
> When I put a signal on P0.11 I never get any interrupt out of it.
> Signal looks good, 100us square pulse.
>
> I threw a test bit of code to set the soft int in another timer
> routine - when I have a breakpoint in my ISR I repeatedly hit it as
> expected, but never with just the signal.
>
> I am wondering if anyone else has used a GPIO interrupt in this
> fashion and had success? I can't find anything relating to this
> problem with the LPC23xx - but there are some issues for the other
> LPC21/22xx series having to do with order, etc. Could one of these
> things be an issue here as well?
>
> Thanks in advance for any advice on this issue.
>
> Sean
>

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