LS1046A RDB: GPIOs for testing gpio interrupt handling performance of linux

[srechermann]

Hi,

I am working with an LS1046ARDB and want to measure interrupt latency. My goal is to trigger an interrupt via an external signal generator (Input GPIO) and toggle another pin (Output GPIO) in response, measuring the delay with an oscilloscope.

I am looking for accessible pins on the board headers that can be muxed as GPIOs.

My idea is to use the IEEE-1588 Header (J11) but not sure if this will work and what I have to do.

The Reference Manual states that EC2 pins can be configured as GPIO3 via the RCW (EC2=1).

If I set EC2=1 in the RCW, will these signals be routed to J11?
Are there other easily accessible Pins on the LS1046A RDB I can use for this?

Thanks for your help

[yipingwang · Accepted solution]

You could use the GPIO muxed with SPI signals.
GPIO_2[1], GPIO_2[2], GPIO_2[3] SPI interface is unused on RDB and terminated to test points.

Please refer to "Table 3-8. SPI Signal configuration" in LS1046ARM for details.

[srechermann]

Thanks for your help! This should work. I found out the GPIO_2[1], GPIO_2[2], GPIO_2[3] correspond to TP14, TP13 and TP11