Description

After successfully booting in SD mode on a ZCU102, I am not able to connect to the PSU using XSDB to debug:

xsdb% targets
  1  PS TAP
     2  CSU
        3  MicroBlaze CSU (Running)
     4  PMU
        5  MicroBlaze PMU (Running)
     6  PL
  7* DAP (AP transaction error, DAP status 50000021. No debug power)
xsdb%

Solution

In early ZCU102 psu_init configuration, MIO26 was configured as an input for the PMU (which is connected to the PMU ROM interrupt).

On the board this pin is left for user configuration and driving spurious interrupts to the PMU.

The work-around is to NOT configure the PMU GPI 0 as MIO26 in Vivado.

This is now the default for the ZCU102 board template.