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Date of registration: May 15th 2018

Posts: 1


Tuesday, May 15th 2018, 9:44am

J-Link with ASIC (R5, M0+): Unable to Connect to Target


I have a custom board for a custom ASIC. The ASIC has R5 and M0+ cores.
I have wired VCC, GND, RESET, TMS, TCK, TDI and TDO from the board to the J-Link's 20 pin header.

When I give connect, I get the option to choose the CPU core which was selected as Cortex-R5. But the debugger is unable to connect to the target.

Commander log is given below:

SEGGER J-Link Commander V6.32b (Compiled May 8 2018 18:26:51)
DLL version V6.32b, compiled May 8 2018 18:26:33

Connecting to J-Link via USB...O.K.
Firmware: J-Link V9 compiled Apr 20 2018 16:47:26
Hardware version: V9.30
S/N: 269307276
License(s): FlashBP, GDB

Type "connect" to establish a target connection, '?' for help
Please specify device / core. : CORTEX-R5
Type '?' for selection dialog
Please specify target interface:
J) JTAG (Default)
Device position in JTAG chain (IRPre,DRPre) : -1,-1 => Auto-detect
Specify target interface speed [kHz]. : 4000 kHz
Device "CORTEX-R5" selected.

Connecting to target via JTAG
TotalIRLen = ?, IRPrint = 0x..000000000000000000000000
TotalIRLen = ?, IRPrint = 0x..000000000000000000000000
TotalIRLen = ?, IRPrint = 0x..000000000000000000000000
TotalIRLen = ?, IRPrint = 0x..000000000000000000000000
Cannot connect to target.
Please let me know the exacts steps to connect and debug the target.



Super Moderator

Date of registration: Jan 2nd 2017

Posts: 1,048


Wednesday, May 16th 2018, 12:14pm

Hello Raj,

Thank you for your inquiry.
Generally R5 cores are supported and should at least return some information when J-Link tries to connect to them.
According to your log J-Link does not get any response whatsoever.
Could you check if your wiring is compatible to the one described in the J-Link user manual?
Depending on your ASIC implementation additional init steps are needed. For this J-Link Script files can be user.
More information about them can be found in the J-Link user manual as well.

How to add support for unsupported target devices the following guide can be used:

We noticed that you are using a J-Link EDU.
Are you using the J-Link EDU for a commercial project? Keep in mind that a J-Link EDU may only be used for evaluation purposes and educational/private use, any other use would violate the license agreement.

Best regards,
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