Interrupt problem from pio

Question

I am using the Cyclone IV GX Transceiver Starter Board and Quartus 12.1 tools.

Using the "Board Test System" example, I built and loaded the sof and built and run the Neos "Count Binary" example.

I modified the isr by adding a printf to see the processing occurrs. On first run, I did not receive interrupts.

I then examined the button_pio in SOPC. Interrupts and edge register were not enabled.

Once these features were enabled, I get a continuous stream of interrupts. (Not simply from pressing the button).

I have tried various combinations for edge and level settings but see the same continuous result.

Can anyone point me in the right direction?

altera_forum · Answer

Discovered the problem!!

Buttons are an active high. Edge capture was set to rising. Changed to falling.

Also, the Count binary template reset the edge capture register to 0. Changed to 1.

It works.

Forum Discussion