How to upgrade a custom LPC55S69 using ISP mode USART

[sushmasan]

Hello Team,

I have different application notes about ISP mode, but it was not clear to me.

I am trying to understand the different steps involved in upgrading a custom LPC55s69 microcontroller using ISP USART mode.

Can someone please provide some insights about it?

Regards,
San

[sushmasan]

Hello @ZhangJennie ,

Just wanted to check,

as per the comment in this link,

https://community.nxp.com/t5/LPC-Microcontrollers/how-to-enter-ISP-mode-via-software-LPC55S69/td-p/1...

"For LPC55S69 1B, according to UM, no way to enter ISP mode with code. "

So, can't we enter into ISP mode via software at all?

Let's say, If I want to use Flexcomm 0 interface to do the firmware upgrade, which means LPC55s69 has to enter into USART-ISP mode. 

I am planning to use USART PIO0_29 as RX, PIO0_30 as TX for firmware upgrade.

How can I achieve firmware upgrade using these pins in the ISP mode?

Regards,
San

Regards,
Santhosh

[ZhangJennie]

Hi sushmasan,

The link you refered was in 2020 . Device with date code 2101 (yyww) onward has workaround. see errata

https://www.nxp.com.cn/docs/en/errata/ES_LPC55S6X.pdf

But if the date code is before 2101, there is no wrokaround.

Hope this helps,

Jun Zhang

[sushmasan]

Hi @ZhangJennie ,

Thanks for the update, let me go through the errata you have shared.

Regards,

San

[sushmasan]

Hello @ZhangJennie ,

I went through the errata, and understand that

User should use below code in their application to invoke auto ISP mode instead of runBootloader API.

The work around is bring the device into auto ISP mode, where as I would like to USART-ISP mode. How can I achieve that?

Regards,
San

[ZhangJennie · Accepted solution]

Hi sushmasan,

With the workaround we can only achieve auto isp mode. in the default Auto ISP mode which will scan all the available interfaces looking for activity. If usart is available, it will go to uart isp.

Thanks,

Jun Zhang

[sushmasan]

Hi @ZhangJennie ,

Thanks for the update.

[ZhangJennie]

Hello @sushmasan ,

I would suggest you reading this article. I believe it will help you.

https://community.nxp.com/t5/LPC-Microcontrollers-Knowledge/LPC55-Update-Firmware-in-USB-UART-SPI-I2...

Have a nice day,

Jun Zhang

[sushmasan]

Hello @ZhangJennie ,

I already went through the details in the link you provided, but it was not clear to me. Let me read it again.

Thanks.

Regards,
San

[sushmasan]

Sorry, some clarification is missing in my previous message. Please see the update.

I went through* different application notes about ISP mode, but it was not clear to me.