LPC55S69 flash imaging & debugging on production board (newbie)

[randi_eck]

We're designing our 1st ARM board. Most examples assume the IDE & devkit board. Right now the design does not include an ISP or RESET button. It's a low-volume board. There's some confusion in the team about what pins we'll need to support (SWO?, SWCLK?, SWDIO?, RESET?, GND?, PIO0_5?, P0_29 and P0_30?)

1) What is typically used by the board manufacturer to image the flash?

2) What is typically used to upgrade the flash image after the board is already imaged? It needs to be something simple that the techs can use, rather than the whole IDE. blhost with some probe (and which probe)?

3) What is used to debug on the production board, rather than on the devkit? Can the devkit board be used when switched to debug an external device rather than the LPC55S69 on the devkit board?

4) And can all this be done without putting the 10-pin debug header on the board, if we make our own cable?

Thanks,

Randi

[randi_eck]

Thank you. We'll put an ISP button on the Beta boards. Our problem is that the board will run in a totally sealed environment, with no physical access to the ISP button. Eventually we'll write our own bootloader, but until then is there any way to assert the ISP pin programmatically? And, if so, can it be done without Secure Boot?

[ZhangJennie]

I have checked with system engineering team several days ago. No way to enter ISP boot mode without assert ISP pin.

Have a nice day,

Jun Zhang

[ZhangJennie · Accepted solution]

HI

We recommend to program/update firmware with blhost in ISP mode. You need press ISP button to enter ISP mode first.LPC55S69 1B doesn't allow to enter ISP mode without assert ISP pin.

For steps, I suggest you read AN12283. 

If you want to use secondary bootloader to update firmware, refer AN12327.

NXP demo board integrates debug probe on board, if you design your own board, you need to leave SWD pin and have an external debug probe. for example,

https://www.nxp.com/design/development-boards/lpcxpresso-boards/jtag-swd-debug-probe:MCU-LINK

LPCXpresso55S69 can be also used as debug tool. here is a photo of using one LPCXpresso55S69 board to debug another , Please check the demo board user manual for the jumper setting for this purpose.

To design your own SWD interface, refer this article

https://community.nxp.com/t5/LPCXpresso-IDE-FAQs/Design-Considerations-for-Debug/m-p/469565

Hope this will help you,

Jun Zhang