U-boot on 4337

[lpcware]

Content originally posted in LPCWare by bomellberg on Fri Oct 10 02:30:36 MST 2014
Hi everyone,

New to this forum, but not to forums in general. I have searched for my specific situation on several forums.

I have a custom board with an LPC4337. The board has wired USART2, USART3 and USB0 for communication with the outer world. Also wired is external SDRAM and external flash.

I have successfully compiled and programmed the chip with blinky examples, using LPCXpresso and Flash Magic. Since the board is made for wireless communication (via the USB0 to the WiFi module), we are looking at the possibility to use uCLinux as OS, for easy inclusion of peripherals. (If this is overkill, please let me know. FreeRTOS might be another road). So the next task is to get u-boot onto the chip.

I have tried to use the Emcraft version of u-boot for the Embedded Artists LPX4357 OEM board. The have made a port for the LPC4357-chip, wich is identical to the 4337 except for the LCD driver.

Nomatter how I poke around in the config files, I cant get communication with the USART3. The bin file is converted to hex, and downloaded using Flash Magic, but nothing comes out of the USART3 port, not even garbage.

Could anyone point me in the right direction, what needs to be done to perform these changes?

Regards,

/Bo Mellberg

[lpcware]

Content originally posted in LPCWare by bomellberg on Tue Oct 14 00:55:36 MST 2014
Solved it by reading the datasheet.

When you move to another USART, don't forget that those multiplexed pins have different FUNC-numbers. USART0 is multiplexed as FUNC=1 on P2.0 and P2.1, but USART3 is multiplexed as FUNC=2 on P2.3 and P2.4.

After I made the changes to both the groups and pins in the ea-lpc4357.h-file, as well as the FUNC change in the board.c-file U-boot starts up nicely on USART3.

/Bo