topic Re: 5V KE06Z Bootloader/SWD over 3.3V? in Kinetis Microcontrollers

5V KE06Z Bootloader/SWD over 3.3V?

codyhubman — Tue, 12 May 2020 21:31:05 GMT

So I'm worried that only the 3.3V node will work for the bootloader to SWD.

I connected pins 2&3 on J14 of the FRDM board. I now have 5 Volts running to the board I am trying to program. However the bootloader now fails every time I try to upload my SREC file. It did work with the 3.3V for pins 1&2 of j14.

Here's the dilemma and we may just have to deal with this but I was hoping maybe you guys knew why the 5v wasn't working.

On the target MCU the Vdd node is tied to a 5 Volt regulator. And this is currently presumed to be causing the FRDM board to fail after awhile (usually after 30-40 uploads). I wanted to try to get the 5v working so there wouldn't be competing voltages at the same node. Does anyone have any material/information on this or is this thing not going to work with 5 Volts? It was hard to determine from the ke06z user guide.

Thanks for any help

-Cody

Re: 5V KE06Z Bootloader/SWD over 3.3V?

kerryzhou — Thu, 14 May 2020 08:50:43 GMT

Hi cody hubman ,

Thank you for your interest in the NXP kinetis product, I would like to provide service for you.

Please note, in the FRDM-KE06 board, the on board debugger is the K20 chip, this chip just the 3.3V chip, can't work with 5V.

So, it means your debug SWD interface still 5V, not 3.3V, maybe this caused the unstable issues.

So, I think you can use the 3.3V to download the code, then check your code function with 5V.

Or another way, you can use the external debugger which can support 5V, just don't use the on board debugger.

Wish it helps you!

If you still have questions about it, please kindly let me know.

Kerry

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Re: 5V KE06Z Bootloader/SWD over 3.3V?

codyhubman — Thu, 14 May 2020 13:46:18 GMT

So we have already developed our own board using the KE06z128. But the problem we are suspecting is that the target board's 5V regulator is somehow draining the 3.3v on the on the freescale board.

For more context, we do actually use the 5v to power the KE06z on our board and after the code is uploaded it works totally fine. But as you mentioned the 5v on the freedom board does not.

We were wondering if it's possible to use a logic shifter to program the target board? We would take the 3.3v output from the Freedom board. We would send it into a logic shifter. From the logic shifter we would attempt to program our target board with the 5v?

Re: 5V KE06Z Bootloader/SWD over 3.3V?

kerryzhou — Fri, 15 May 2020 02:40:37 GMT

Hi cody hubman，

I mean that the FRDM-KE06 on board debugger opensda is 3.3V power.

So, if you want to match the 3.3V to 5V, I suggest you use the logic shifter to transfer the 3.3V to 5V or 5V to 3.3V, to keep the debugger working stably.

Wish it helps you!

If you still have questions about it, please kindly let me know.

Kerry

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Re: 5V KE06Z Bootloader/SWD over 3.3V?

codyhubman — Fri, 15 May 2020 02:43:46 GMT

I will give it a shot and if it is successful I will be back and mark your answer! Thanks for all the help :smileyhappy:

Re: 5V KE06Z Bootloader/SWD over 3.3V?

kerryzhou — Fri, 15 May 2020 03:15:13 GMT

Hi cody hubman,

You are always welcome!

Best Regards,

Kerry

Re: 5V KE06Z Bootloader/SWD over 3.3V?

codyhubman — Thu, 21 May 2020 16:52:32 GMT

So we attempted to use the logic level shifter to bring it from 3.3V to 5V. The bootloader fails and does the 3 blinks at a time. I took all the signals in and out of the shifter. We are using a CD40109B shifter. Do you have any potential suggestions... I can post the circuit too if you prefer and might have an idea

I essentially tie all the enables to the 3.3
Then feed the SDA, SCL, Reset through the shifter. Have the output powered by 5v and thats it

Re: 5V KE06Z Bootloader/SWD over 3.3V?

codyhubman — Thu, 21 May 2020 16:53:37 GMT

Also It does appear that I am getting signals through the shifter

Re: 5V KE06Z Bootloader/SWD over 3.3V?

kerryzhou — Fri, 22 May 2020 09:04:21 GMT

Hi cody hubman,

Please share your CD40109B related circuit.

Do you check the each side voltage, whether it is correct when send the datas?

If you still have questions about it, please kindly let me know.

Kerry

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