I have a electronic with a MFC5270. The electronic runs fine except, when tested in the assembly line.
The BDM/Debug port is contacted by needles to achieve connection to a programmer Unit.
If the needles are connected to the electronic, the µC sometimes does not start-up. This happens
with and without the programmer. It seems as if only the wires can prevent the µC from starting up.
All observations I have, is, that the µC activates the DDATA and PST lines for a short sequence.
If start-up does not work, PSTCLK goes to a 100MHz oscillation. In case of successful start-up, all lines
are quiet after this sequence.
The electronics schematic is according to Freescale's recommendations (copy from evaluation board).
Is there any detailed information about safe start-ups and disturbances on the BDM/Debug-port?