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Altera_Forum
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15 years ago

Can't reset PIO edge capture using IOWR_ALTERA_AVALON_PIO_EDGE_CAP

Dear experts, I am Nios beginner. I wonder why I cannot reset the edge capture register using IOWR_ALTERA_AVALON_PIO_EDGE_CAP (to reset it inside my ISR)? //after first interrupt...
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Altera_Forum
Icon for Honored Contributor rankHonored Contributor
15 years ago

Hi skw

In order to reset the edge capture register you must write one to the bits you want to reset, not write zero into the register.

Then, this line

IOWR_ALTERA_AVALON_PIO_EDGE_CAP (PIO_BASE,0);

must be changed in

IOWR_ALTERA_AVALON_PIO_EDGE_CAP (PIO_BASE, IRQ_BIT_MASK);

For example, if your irq signal is connected to pio bit 5, you'll define IRQ_BIT_MASK = 0x40

Regards