Push button - Interrupt comes for both edge even though configured for rising edge only

[dhanaraj_d]

Hi,

We are having custom design board which using imx7d processor. Push button is implemented on the board - when we given rising edge configuration, we verified register settings of GPIO showing right values in GPIO interrupt configuration register and GPIO edge select register. But on both rising and falling edge event we are getting interrupt. This we tested in IMX7D SABRE reference board and there this issue is not seen. We don't have debounce logic also to suppress this issue. Can anyone help here to solve this issue if they face similar issues in their design.

Thanks in advance.

[igorpadykov]

Hi Dhanaraj

if issue happens only on custom board this may be caused by signal ringing,

one can try to add small capacitor on that line, try to set HYS bit (Hyst. Enable Field) in

IOMUXC_SW_PAD_CTL_PAD_x_y register.

Best regards
igor
-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------

[dhanaraj_d]

Hi Igor,

Thanks for your reply.

Even though we enable Hysteresis also same issue is coming. We would like to fix this through software and not with any hardware change. One change from my reference board to here is enabled internal pull up in my target board. 

Register value(IOMUXC_SW_PAD_CTL_PAD_SD2_RESET_B) is 0x32.

Suppose if we not enable that pull up, then i faced continuous interrupt(10-15 times).