JTAG not working on K210-test_v0.2



  • I'm trying to connect with JTAG but I'm getting errors.
    I use a Segger J-Link EDU. The output of OpenOCD is below and you can see that "VTarget = 0.000V". This suggests that JLink is unable to sense the board at all.
    Do I need to enable JTAG on the board via some firmware update or some jumper?

    Thanks.

    adapter speed: 3000 kHz
    Info : J-Link V10 compiled Jul 23 2018 09:53:14
    Info : Hardware version: 10.10
    Info : VTarget = 0.000 V
    Info : clock speed 3000 kHz
    Error: JTAG scan chain interrogation failed: all ones
    Error: Check JTAG interface, timings, target power, etc.
    Error: Trying to use configured scan chain anyway...
    Error: riscv.cpu: IR capture error; saw 0x1f not 0x01
    Warn : Bypassing JTAG setup events due to errors
    Error: Unsupported DTM version: 15
    Info : Listening on port 3333 for gdb connections
    Error: Target not examined yet


  • Staff

    @DualTachyon Brilliant!



  • I have it working now. A jumper was not present on one of the JTAG pins.

    adapter speed: 3000 kHz
    Info : J-Link V10 compiled Jul 23 2018 09:53:14
    Info : Hardware version: 10.10
    Info : VTarget = 1.813 V
    Info : clock speed 3000 kHz
    Info : JTAG tap: riscv.cpu tap/device found: 0x04e4796b (mfg: 0x4b5 (<unknown>), part: 0x4e47, ver: 0x0)
    Info : Examined RISCV core; XLEN=64, misa=0x800000000014112d
    Info : Listening on port 3333 for gdb connections
    Info : [0] Found 4 triggers
    halted at 0x80007be8 due to debug interrupt



  • I made some progress but not by much. I solved the voltage problem by adding a jumper to J96 header near the JTAG header as shown in schematic.
    However, I'm still not able to scan the device:

    adapter speed: 3000 kHz
    Info : J-Link V10 compiled Jul 23 2018 09:53:14
    Info : Hardware version: 10.10
    Info : VTarget = 1.815 V
    Info : clock speed 3000 kHz
    Error: JTAG scan chain interrogation failed: all zeroes <<<< problem starts here
    Error: Check JTAG interface, timings, target power, etc.
    Error: Trying to use configured scan chain anyway...
    Error: riscv.cpu: IR capture error; saw 0x00 not 0x01
    Warn : Bypassing JTAG setup events due to errors
    Error: dtmcontrol is 0. Check JTAG connectivity/board power.
    Info : Listening on port 3333 for gdb connections
    Error: Target not examined yet