6 years, 6 months ago.

Compiling for LPC11U3X

I have a program that is to big for the LPC11U24 flash space, but I can't afford the board space for the LPC1768. Is it possible to use the online compiler to compile code for the LPC11U37 or LPC11U36 with some configuration? Specifically, do we have access to configure the linker for the extra flash address space? Since the rest of the chip should be the same.

2 Answers

6 years, 6 months ago.

The LPC11u35 is available: https://mbed.org/platforms/EA-LPC11U35/ (and no, I don't have a clue why it doesn't appear in the platforms section, it was there, and then it was removed, no idea why, for some reason mbed staff doesn't respond on any questions about it).

Accepted Answer

Careful with that target! I was using it happily for a while, but all of a sudden the binary size nearly doubled, making the extra flash almost worthless. I don't know if they changed toolchains or what. I've been gone so I haven't been able to check it for a few days, but it was still broken as of last Friday. Check out my forum posts here and here for more info. I'm not sure why the mbed staff have been dragging their feet so much with this board. Perhaps it offers so little advantage over their own LPC11U24 board that it's just a low priority. Anyway, NXP just released an LPC11U6X series that offers many improvements over the LPC11U3X like 256KB of flash, 36KB of RAM, a 12-bit ADC, a built in RTC, etc. When I get back, I'm hoping to be able to drum up support for this chip and get it supported since my project has also outgrown the LPC11U24.

posted by Neil Thiessen 30 Jan 2014

Also note that if you use that target, the RAM stats on the Build tab will be wrong. It lists it as having 10KB of RAM, but it only has 8KB of main SRAM. The other 2KB is in a separate block, and is used for USB just like the LPC11U24.

posted by Neil Thiessen 30 Jan 2014

Thanks, I was able to program the LPC11U37 I ordered using the LPC11U35 target early last week. I'm glad I didn't run into the RAM issue Neil was warning me of, as I mainly got the part for the extra flash. This saved me from redesigning the board, so thank you Erik!

@Neil Skimming the LPC11U6X datasheet, I can't seem to confirm if it still has the USB bootloader or not, but either way the LPC11U6X looks amazing! Thanks! EDIT: confirmed: found it on page 444 of the LPC11U6x/E6x User manual (UM10732).

posted by Jason Garner 08 Feb 2014
6 years, 6 months ago.


As I sometimes have the same problem, I choose to use LPC1347. This runs at 72 MHz, has 64 kB flash, 12 kB SRAM.
And of course it's pin compatible AFAIK.