9 Memory Organization

There are three types of memory in PIC18 microcontroller devices:

• Program Memory
• Data RAM
• Data EEPROM

In Harvard architecture devices, the data and program memories use separate buses that allow for concurrent access of the two memory spaces. The data EEPROM, for practical purposes, can be regarded as a peripheral device, since it is addressed and accessed through a set of control registers.

Additional detailed information on the operation of the Program Flash Memory and data EEPROM memory is provided in the “NVM - Nonvolatile Memory Module” section.