Hi,
I am involved in a board bringup with a CortexR4 (NeoS) MCU.
When accessing the JTAG using JLink Commander v5.12, I receive this error:
Communication error when trying to read IDR of AP[0]


The first four registers of the Coresight config block seem to be read correctly, the fifth register is not reporting correct data.

The same data is displayed with several attempts, so noise is most likely ruled out.
Here is the trace:

ARM AP[0]: 0x44770001, AHB-AP
ARM AP[1]: 0x24770002, APB-AP
ROMTbl 0 [0]: 00001003, CID: B105900D, PID:04-003BB907 ETB
ROMTbl 0 [1]: 00002003, CID: B105900D, PID:04-003BB906 ECT / CTI
ROMTbl 0 [2]: 00004003, CID: B105900D, PID:04-001BB908 CSTF
ROMTbl 0 [3]: 00005003, CID: B105900D, PID:04-002BB913 ITM
ROMTbl 0 [4]: 00007003, CID: 37373232, PID:37373232-37373232
TotalIRLen = 4, IRPrint = 0x01 ...

The same trace from a known good working board is:

Found SWD-DP with ID 0x5BA02477
CoreSight AP[0]: 0x44770001, AHB-AP
CoreSight AP[1]: 0x24770002, APB-AP
ROMTbl 0 [0]: 00001003, CID: B105900D, PID:04-003BB907 ETB
ROMTbl 0 [1]: 00002003, CID: B105900D, PID:04-003BB906 ECT / CTI
ROMTbl 0 [2]: 00004003, CID: B105900D, PID:04-001BB908 CSTF
ROMTbl 0 [3]: 00005003, CID: B105900D, PID:04-002BB913 ITM
ROMTbl 0 [4]: 00007003, CID: B105900D, PID:04-008BBC14 Cortex-R4
Found Cortex-R4 r1p4 ...

The JTAG pins have the correct initial voltages

Any ideas on why the first case would return a bogus CID / PID?