LPC5516JVE59 boot mode and CAN interface

[HPT_Dave]

I need a little help understanding how to use the the boot mode and CAN interface (CAN_TX) when both options share the same pin (C6) on the LPC5516JVE59 BGA package. As I understand the documentation, on reset, the processor looks to the boot mode pin (C6 for the LPC5516JVE59) to determine passive or ISP BOOT. I'm planning on using the passive boot mode for my design which requires (?) an external pullup resistor. Once the image is found in the internal Flash, my program will be able to configure the pin to be the CAN_TX option. The confusion I have is the the external pullup will still be present on the CAN_TX pin. Won't this pullup create problems for the the CAN_TX line to perform correctly?

Thanks for the help,

Dave

[ZhangJennie]

Hi HPT_Dave 

LPC5516 doesn't supprot CAN ISP in Boot ROM. It supports USB, SPI, I2C ISP only.

If CAN boot is must, you need to implement your own secondary CAN bootloader with referring 

AN12327 - Firmware Update Using Secondary Bootloader

https://www.nxp.com/docs/en/application-note-software/AN12327SW.zip

and CAN driver demo code unser MCUXpresso SDK folder.

Have a nice day,

Jun Zhang

[HPT_Dave]

Any comments from NXP??