The LPC2468 (and other ARM 7 based devices) are now rather old and were developed befor NXP created any of the standardised device libraries. The best you can hope for are some examples that you can find by Googling. I think Keil have a number of examples on their website, but I don’t think you will find anything useful on the NXP website.
if you can, I’d suggest using a more modern part - the latest NXP parts have quite extensive device libraries in their SDKs.
