Hello,
We made a board with reference of T4240RDB, recently we met a problem which is shown in the title. After many checks,
we found an abnormal phenomenon:
And the second abnormal state is :
The 1st foot of JTAG connector is short circuit.
and the net of the 1st foot, named "COP_TDO" is directly connected to T4240's pin,which is K42.
Now, we are so worried that there is something wrong with the inside of the T4240.
OK,Let me state the problem from the beginning.
Actually, last week, my board had just been ready for the frist time programme. But the first time we connected the debug device to the board, the problem happened. The figure is shown below.
OK, the Chinese characters could be ignored. So, we began to check the relevant hardware.
Finally,we found two abnormal states.