If customer use GPANAIO to GND, it has any side effect on i.MX6Q

[andychien]

Layout of customer have a mistake about GPANAIO to GND. (default must be a no connect)

We found GPANAIO information about this output is reserved for Freescale manufacturing use on table 2-14 in IMX6DQ6SDLHDG.pdf.

We are not sure it has any side effect on i.MX6 chip,  if the pad connect GND.

We use DDR stress test tool via USB OTG and result run start calibration fail.

(Other customer's i.MX6 board use the same DDR parameters could run pass over 600MHz)

Could you have explain and any suggestion?

Thanks a lot,

[LinWang · Accepted solution]

Hi Andy,

Please find feedback from design team.

I don't think there is any impact to any analog functional performance if this pin is shorted to ground, however, the recommendation to float stems from the ability of this pin to be programmed as an output of the bandgap or regulators where if this was to happen in this customer board them the system could potentially shut-down.

[LinWang]

Hi Andy,

For your GPANAIO question, I send ticket for asking design team's help.

and will reply you when i get feedback.

For your second question.

Please help to check below items.

1. if DDR script are configured properly? (other customer's board may use different DDR chip)

2.Please use latest calibration tool to do that.

Please refer to following info.

i.Mx6DQSDL DDR3 Script Aid

https://community.freescale.com/docs/DOC-94917

i.MX6 DDR Stress Test Tool

https://community.freescale.com/docs/DOC-96412