[MinnowBoard] Problem booting with activity on I2S_FRM
dvhart at linux.intel.com
Fri Mar 27 23:45:29 UTC 2015
On 3/27/15 2:24 PM, Lucas De Marchi wrote:
> I'm using the pin GPIO_I2S_FRM for gpio in my application. However
> when I boot the board, if there's any activity on this pin already,
> the board doens't boot. I get nothing on serial, not even the messages
> from the bios. As far as I tested this is the only pin that exhibits
> this behavior.
> Firmware version is 0.78. Is there anything that can be done to boot
> the board even with activity on this pin?
Thank you for reporting this Lucas. I've looked into the design
documents and that pin is also a strapping line which happens to select
the BIOS boot:
While there is a buffer/voltage-shifter between the LSE connector and
the SoC, it is possible that a low signal to the LSE connector is
causing the SoC side of the signal to be pulled low, overpowering the
10k strap pull-up, effectively telling the SoC to boot via LPC instead
of SPI, causing the issue you describe.
Can you describe exactly what activity you have applied to this pin at boot?
Intel Open Source Technology Center
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