Low Voltage measured on VCC_PSINTFP

[Christopher Simmons]

I am currently trying to track down an issue which is preventing me from connecting to the board over JTAG when petalinux is booted. In hardware manager, the gui is repeatedly indicating that the devices are appearing and disappearing from the chain, in a rapid fashion. The same exact behavior occurs when using a different JTAG adapter (SmartLynq). If I set the mode switches to JTAG boot, the connection seems to be stable and I can download a bitstream successfully.

As part of troubleshooting I have measured voltages which are supplied in the SiP and have bypass caps on the back. The only voltage that concerns me is the VCC_PSINTFP rail, I am measuring across C69. The other rails are very close to their targets.

When booting off of the SD card I read 0.775 volts, with a calibrated meter (I have tried both the provided SD, and my own petalinux image which I have been doing development with).

When the mode switches are set for JTAG I measure 0.806 volts.

Any guidance on how to resolve my JTAG issue and get the zu3 running with a rail which is within tolerance is appreciated.

Thanks

 

[Author]

Posts