The user manual says that the device ID register at 0x400483f4 should contain 0x00007c00. However, when I run code on the chip, I find that 0x400483f4 contains 0x1000002b and 0x400483f8 contains 0x00007c00. Depending how you look at it this is either an error in the user manual or an error in the silicon. What is "correct" and how will NXP repair this problem?
The user manual is incorrect. The PARTID values are available at address 0x400483F8.
This will be addressed in the next revision of the user manual.
I can see some confusion in the manuals...
LPC11xx: Older devices (non-XL types) are documented correctly, i.e. DEVICE_ID is at offset 0x3F4. XL devices are missing, but probably their ID is to be read from offset 0x3F8 (I must still verify this).
LPC11Uxx: The LPC11U1x and LPC11U2x series are documented correctly, i.e. DEVICE_ID is at offset 0x3F4. LPC11U3x devices are missing, and their ID is at offset 0x3F8 (see UM table 377 for the actual ID codes).
I will double-check all this once I'm back in the office, and submit a change request for the manuals.