AGX Xavier 40-pin header I2S2_CLK pin is interfering with Xavier SPI normal operation

Hi,

I have an problem in Xavier operation,
I have noticed that if Pin-12 (I2S2_CLK) of the Xavier 40-pin header is pulled down during the Xavier power-up sequence, it affects the SPI 1 operation.

We have connected our system to the Xavier 40-pin header. However, if our system is down during the Xavier power-up, the SPI stops working. On the other hand, if our system is on during the power-up, the SPI_1 works correctly.

Can you please provide me with the Xavier GPIO hardware default configuration after power is on? I suspect that during power-up, the Xavier is trying to set this pin to “HI,” and because our system is off, we might be causing the XAVIER current limit to start working.

Thank you for your assistance.

Best regards,
Nir Bechor

Hi aradmosh,

Are you using the devkit or custom board for AGX Xavier?

Does the difference between these two situations as following?

  • Your system down => Pin-12 (I2S2_CLK) pulled down
  • Your system on => Pin-12 (I2S2_CLK) pulled up

Have you also checked the status of SPI1 related pins in these two cases?

It could be configured from pinmux table.

Hi Kevin,
Yes, I am using Jetson AGX Xavier Developer Kit with customs board that connect to the Xavier 40pin header.
The difference between these two situations is as you described:

  • My system down => Pin-12 (I2S2_CLK) pulled down
  • My system on => Pin-12 (I2S2_CLK) pulled up,
    I have check the SPI1 related pins the CS0 isn’t functioning as it should he don’t reach 1.8V only 1V.
    “It could be configured from pinmux table.” - Please elaborate, the default GPIO configuration isn’t configured by hardware?
    I am talking on the first second that i power on the Xavier Developer Kit, and not after the system in booting on.

Thank you
Nir

The carrier board should not power on before module so that module won’t be affected by carrier rails. So any pin of module should not be affected by carrier power rails before module on. You should not pull up the pin during boot.

Can you please provide me with the Xavier GPIO hardware default configuration after power is on, so i will be able to understand the issue?

You can get POR of each pin in pinmux sheet. Anyway, no matter what POR is, carrier power rails should always be ON after module.

This topic was automatically closed 14 days after the last reply. New replies are no longer allowed.