I need to learn how to use the AUX RAM of the LPC932
AUX RAM, ERAM etc (no name has standardized) is, probably, the most confusing thing about the new derivatives with this feature.

The AUX RAM is - hang on - internal external RAM!

Until a few years ago no '51 derivative had any data storage beyond the (I)DATA and if you wanted more you added XDATA by attaching an external RAM chip to P0 and P2.
Now - glory be - there are derivatives where some such RAM has been added to the uC chip itself. Since it is internal, you can enjoy the fact that you have not loacked P0 and P2 up for this purpose.

So, treat the AUX RAM as if it was an external RAM chip (XDATA) and everything will work.
Whatever your compiler/assembler manual and other litterature say about XDATA you just apply.

Erik