10.2 In-System Reprogrammable Flash Program Memory

The ATmega328PB contains 32 Kbytes on-chip in-system reprogrammable Flash memory for program storage. Since all AVR instructions are 16 or 32 bits wide, the Flash is organized as 16K x 16.

The ATmega328PB Program Counter (PC) is 14 bits wide, thus addressing the 16K program memory locations. The operation of the Boot Program section and associated Boot Lock bits for software protection are described in detail in Boot Loader Support – Read-While-Write Self-Programming. Refer to Memory Programming for the description of Flash data serial downloading using the SPI pins.

Constant tables can be allocated within the entire program memory address space, using the Load Program Memory (LPM) instruction.

Timing diagrams for instruction fetch and execution are presented in Instruction Execution Timing.