Hi
if lpc11u24, we use lpcopen for lpc11u14 rather than lpc11c24
LPC11U14 can be downloaded:
https://www.nxp.com/design/microcontrollers-developer-resources/lpcopen-libraries-and-examples/lpcop...

The difference of lpc11u24 and lpc11u14 is that lpc11u24 has larger sram, eeprom is integrated in lpc11u24 but not in 11u14.
lpcopen for lpc11u14 project can work on lpc11u24 directly. if you want to extend memory, for example you want to use eeprom which is not defined in lpc11u14 project, you need to change it to a lpc11u24 project, Just adjust memory details based on lpc11u24 memory map

All chip and board libs and user applications for lpc11u24 are needed to be adjusted.

Hope this helps,
Jun Zhang