Hi everyone, I have a problem. I have a custom board, and I burn DAP_SJC_SWD_SEL fuse in order to change from SWD to JTAG
With SWD, the board worked very well, and when I changed that fuse, j-link can't connect with the target, it appers:
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.
My board has connected this pins from IMXRT1051 to JTAG and it doesn't have other use.
I hope you can help me, thanks.
Vanessa
Hello @vanessa_dis,
Only to confirm, does the JTAG_MOD pin is tied to ground as the hardware design guidelines mention?
Best Regards,
Alexis Andalon
I tried to read and print the values of JTAG_MOD (with an image), but it showed me this errors, so I think this is not a way to verify JTAG_MOD
also I would like to say that before doing this modification I had experimented some errors when I tried to erase my flash via J-LINK,
and reading I found that I had to unlock kinetis but it didn't work
Do you think this is like a kind of reason that connect with JTAG doesn't work? (even thought, this is rare because with SWD worked perfectly with this problem) Or do you thing that this is other independent problem?
I hope you know something about it,
Vanessa
Hello @vanessa_dis,
As you mention the JTAG_MOD should be at 1 if want to enable the secure JTAG. In the following application note mention all the steps to follow to enable the secure JTAG.
Best Regards,
Alexis Andalon
Yes, but first I changed from SWD to JTAG, and for that reason this error appears to me
Just to confirm, the resistor must be connected to JTAG_MOD from GND always? I mean, if later I want to configure secure JTAG, and I need to put JTAG_MOD to HIGH is there not any problem because of the resistor?
Thanks for your answer Alexis,
Yes, in fact I incorrectly removed that resistor, but now I soldered again that. Even I was connecting manually to GND and source,
and I know this works because before I switched to JTAG, I tested with SWD (GND manually of JTAG_MOD).
Regards,
Vanessa
I did this because I want to use Secure JTAG but I've read it's better test JTAG first and then Secure JTAG.
or I have to burn all the fuses without test JTAG only?