The Non-Volatile Memory (NVM), like the Programmable Flash Memory (PFM) in the PIC18F57Q43, is accessed using a new user interface called NVMUI. This uses a special bank at the end of the GPR space to act as a buffer for memory transfers and is called Buffer RAM. All page read/write operations on NVM use buffer RAM to transfer data. Refer to the device data sheet for more information.