In-System Reprogrammable Flash Program Memory

The AVR64DD14/20 contains 64 KB on-chip in-system reprogrammable Flash memory for program storage. Since all AVR instructions are 16 or 32 bits wide, the Flash is organized with a 16-bit data width. For write protection, the Flash program memory space can be divided into three sections: Boot Code section, Application Code section, and Application Data section. The code placed in one section may be restricted from writing to addresses in other sections. The Program Counter can address the whole program memory.

Refer to the Code Size (CODESIZE) and Boot Size (BOOTSIZE) descriptions and the NVMCTRL - Nonvolatile Memory Controller section for further details.

The Program Counter can address the whole program memory. The procedure for writing Flash memory is described in detail in the documentation of the Nonvolatile Memory Controller (NVMCTRL) peripheral.

Each 32 KB section from the Flash memory is mapped into the data memory space and is accessible with LD/ST instructions. For LD/ST instructions, the Flash is mapped from address 0x8000 to 0xFFFF. The entire Flash memory space can be accessed with the LPM/SPM instruction. For the LPM/SPM instruction, the Flash start address is 0x0000.

Table 1. Physical Properties of Flash Memory
Property

AVR64DD14

AVR64DD20

Size 64 KB
Page size 512B
Number of pages 128
Start address in data space 0x8000
Start address in code space 0x0