Enter, enable EZPORT via JTAG

[schwimmen]

Hello there,

i am using the MK64FX512.

I was successfull in entering both, JTAG and EZPORT with the right EZP.CS and reset start sequences.

My problem now is: i want to enable EZPORT not via RESET sequence, but via JTAG. If you look into the datasheet at the chapter JTAG Controller you find the EZPORT enable JTAG-instruction. But there is no description of this instruction.

I tried the following out:

 - enter JTAG

- reset JTAG

- write 0xd to the instruction register

- enter run test/idle state

- try to reach EZPORT

I found out, that after writing 0xd into the instruction register and entering idle, the chip itself stays at reset state (no pull-up an the reset pin asserted from the chip itself) until JTAG wasn't reset.

The program i programmed to the chip before has the EZPORT disabled in the flash configuration field. Is it possible to enable EZPORT although it is disabled in the flash config field? Maybe i must do an mass erase before trying to reach the EZPORT?

Any ideas?

Thank you!

[schwimmen]

Ok, i've understood JTAG a bit, or better the interaction between the JTAG-DP and JTAG-AP. So now i was successfull in mass erasing the chip and therefore using EZPORT again on it.

But nevertheless it would be interesting to know the EZPORT enable command in the JTAG works. If it needs a certain time to start EZP, if there are any registers where you can see if the EZP was started successfully. In the manuals or application notes for the chip i am using, this command is not documented. Also i can't find in any other documents information about this command.

Regards,

Wim

[FelipeGarcia]

Hello Wim,

I have received the following feedback from internal team.

It not possible to enable EZPORT although it is disabled in the flash config field.

for more information on EZPORT, please refer to How to use EzPort module

for noted that EZPORT is old programming interface, and further parts will not have it.

Best regards,

Felipe

[FelipeGarcia]

Hi Wim,

It is true that there is not enough information regarding this issue. I am going to ask this internally to see if there is any information I can provide. I will let you know as soon as I receive any update.

Regards,

Felipe

[FelipeGarcia]

Hello Wim,

Does EzPort work correct if you configure Flash Configuration Field? 

Are you able to establish communication over EzPort (read the EzPort status register)?

Regards,

Felipe

[schwimmen]

Hello Felipe,

the chip i try to reach via EZP is disabled via the flash configuration. At other chips i've changed the firmware, so EZP is enabled in the flash config. At these chips i have full access.

I know the chip i've tried is working, because i see the program running and i have connection via JTAG.

Because i am new to JTAG, i don't know how do a mass erase over JTAG. It's hard to find any documentation, which is easy to read. All i know is, that i can reach flash using the ARM JTAG-DP. But how to use commands and select registers and stuff, i don't really now and it is hard to find out via the ARM documentary.don@t

I've tried out to activate EZP via JTAG on a chip, where EZP is enabled in the flash config. There still is the same - the chip will stuck in the TAP or reset state after performing the JTAG-EZPORT command, until i reset the TAP.

Thank you,

Regards,

Wim