Entering ROM Bootloader via UART on MKl03Z32VFG

[richardking37]

Hi All,

I have a board which uses the MKL03Z32VFG4 and I'm trying to connect to it using the blhost utility but I receive the following error: Error: Initial ping failure: No response received for ping command. (I have also tried the KinetisFlashTool)

I am using the following pin configuration:

   pin 3 - PTA3 LPUART0_TX

   pin 4 - PTA4 LPUART0_RX

Searching for similar problems I found Problems entering Bootloader mode. MKL03Z32VFG4. 

The response specifies the following connections are required: PTB1 as LPUART0_TX and PTB2 as LPUART0_RX

Can someone confirm whether these are the only pins that can be used with the ROM Bootloader for a UART connection on this device. I am using the Bandgap which requires an external 100nF decoupling capacitor on the Vref pin - PTB2.

Therefore I made my UART connections on PTA3 & PTA4 as noted above.

Thanks for any assistance.

Richard

[BlackNight]

Hi Richard,

there are several errata which affect bootloader operation on the KL03Z. Have a read at Getting Started: ROM Bootloader on the NXP FRDM-KL03Z Board | MCU on Eclipse 

I hope this helps,

Erich

[richardking37]

Hi Erich,

Thanks for the link to your article Getting Started: ROM Bootloader on the NXP FRDM-KL03Z Board | MCU on Eclipse it's very clearly written and I found it a great help in understanding how to use the ROM Bootloader.

Best regards

Richard

[kerryzhou · Accepted solution]

Hello Richard King,

    As you know, the KL03 have the on chip ROM bootloader, you can find the details from the according reference manual.

  

Then rom bootloader UART pin, is just the PTB1 and PTB2.

If you want to use the other pin as the uart bootloader pin, you can't use the ROM bootloader, maybe you need to use the flashbootloader, which is a sector of code should put in the flash. But 32K flash size is very small if you want to use the flash bootloader.

   PTB2 is just the VREF_OUT.

   But I don't whether you already connect PTB2 to the other place? Maybe in your board, you can use a jumper, when you want to use the bootloader function, you can don't connect the VREF_OUT circuit, otherwise, connect it.

Maybe you can try it.

If you still have question, please let me know!

Have a great day,
Kerry

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[richardking37]

Hi Kerry,

Many thanks for your reply. As you point out the boot loader muxing is shown in Table 1.1 but if planning on using the on chip VREF the requirement to have a 100nF cap on PTB2 might catch others planning on using the boot ROM and on chip VREF. It is of course possible to link out the 100nF cap but this isn't always a viable option.

The ROM bootloader would have been a nice to have feature but isn't a requirement for this project so it isn't a problem but worth remembering for the future.

Best regards

Richard