
16
8161D–AVR–10/09
ATmega48PA/88PA/168PA/328P
7.
AVR Memories
7.1
Overview
This section describes the different memories in the ATmega48PA/88PA/168PA/328P. The AVR
architecture has two main memory spaces, the Data Memory and the Program Memory space.
In addition, the ATmega48PA/88PA/168PA/328P features an EEPROM Memory for data stor-
age. All three memory spaces are linear and regular.
7.2
In-System Reprogrammable Flash Program Memory
The ATmega48PA/88PA/168PA/328P contains 4/8/16/32K bytes On-chip In-System Repro-
grammable Flash memory for program storage. Since all AVR instructions are 16 or 32 bits
wide, the Flash is organized as 2/4/8/16K x 16. For software security, the Flash Program mem-
ory space is divided into two sections, Boot Loader Section and Application Program Section in
ATmega88PA and ATmega168PA. See SELFPRGEN description in section
”SPMCSR – StoreThe F lash memory has an endurance of at least 10,000 write/erase cycles. The
ATmega48PA/88PA/168PA/328P Program Counter (PC) is 11/12/13/14 bits wide, thus address-
ing the 2/4/8/16K program memory locations. The operation of Boot Program section and
associated Boot Lock bits for software protection are described in detail in
”Self-ProgrammingParallel Programming mode.
Constant tables can be allocated within the entire program memory address space (see the LPM
– Load Program Memory instruction description).