Hi:
I'm working on my own board which uses S32K344 (maxQFP172), and just after soldering the MCU I found that I cannot connect it to JLink or JFlash with 4-wire SWD interface (GND, SWDIO, SWDCLK, VCC), nor can I download any application either by JFlash or S32DS.
Now the situation is:
1. Direct connect with JLink commander with error:
Unknown SDA AP Id detected: 0xFFFFFFFF
Error occurred: Could not connect to the target device.
2. execute "r0" command: the reset LED on board doesn't lit and the power light on J-link turns to red. (guessing if that's because 4-wire SWD doesn't have a reset pin?)
3. Referencing the post https://community.nxp.com/t5/S32K/Unbricking-S32K146/m-p/937227 , tried to hold the reset button and read the MDM_AP reisters, with error:
Not supported by current CPU+target interface combination
Read AP Register 0 = ERROR
4. Referencing the post https://community.nxp.com/t5/S32K/S32K344-%E8%A2%AB%E9%94%81/m-p/1472192 , tried to hold the reset button and execute "unlock kinetis" command, with error:
Read from DP/AP register failed
I have tried the above 4 steps exactly same on my another S32K344 dev board(functioning properly, can download applications), both with JTAG and 4-wire SWD. The results are:
| JTAG+dev board | SWD+dev board | SWD+my own board | |
| JLink commander: "connect" | Yes | Yes | No (see step1) |
| JLink commander: "r0" | Yes | No (same error as step2) | No (see step2) |
| JLink commander: "SWDReadAP 0" | No (see step3) | ||
| JLink commander: "unlock kinetis" | No (same error as step4) | No (error: Timeout while unlocking device) | No (see step4) |
| JFlash downloading | Yes | Yes | No |
With all these above, I'm wondering:
- Am I using SWD interface correctly? Have I misconnected any pins?
- Is it CORRECT to download any application through SWD rather than JTAG just after soldering the MCU? Do I need to configure any pins or modes before using SWD?
- Why can't I read any MDM_AP registers? I'm assuming this is the same reason that I cannot connect to Jlink.
- Has my S32K344 entered some kind of securing mode? however I scoped the reset pin and it wasn't periodically resetting itself so I guess the MCU wasn't locked.
- Am I using JLink commander correctly? Why would a properly functioning dev board have so many same errors as my own board which basically cannot work AT ALL?
- Is it possible that I got something wrong when soldering the MCU? however I measured the V11 and V25 pins which represents core voltage and the readings seems to have nothing wrong.
Thank you in advance!
