Zynq is running uboot or standalone applications with no issues.
However, when trying to connect ARM in XMD, it reports an AP transaction timeout.
When trying to connect Zynq in XSDB, I cannot see both of the ARMs and APU as expected.
The JTAG chain is fine, because I can connect/download to Zynq when ARM is idle.
What can cause this issue?
Check whether CPU1 is reset by custom uboot or standalone applications.
You can read register slcr.A9_CPU_RST_CTRL to confirm it.
In some cases, customers only use CPU0 in their design, then reset CPU1 and stop clock to CPU1.
However, If CPU1 is under reset, XMD cannot connect to arm correctly.