Rainbow-electronics Atmega169L Manuel d'utilisateur télécharger pdf (Page 15)

ATmega169V/L

2514A–AVR–08/02

AVR ATmega169

Memories

This section describes the different memories in the ATmega169. The AVR architecture

has two main memory spaces, the Data Memory and the Program Memory space. In

addition, the ATmega169 features an EEPROM Memory for data storage. All three

memory spaces are linear and regular.

In-System

Reprogrammable Flash

Program Memory

The ATmega169 contains 16K bytes On-chip In-System Reprogrammable Flash mem-

ory for program storage. Since all AVR instructions are 16 or 32 bits wide, the Flash is

organized as 8K x 16. For software security, the Flash Program memory space is

divided into two sections, Boot Program section and Application Program section.

The Flash memory has an endurance of at least 1,000 write/erase cycles. The

ATmega169 Program Counter (PC) is 13 bits wide, thus addressing the 8K program

memory locations. The operation of Boot Program section and associated Boot Lock

bits for software protection are described in detail in “Boot Loader Support – Read-

While-Write Self-Programming” on page 251. “Memory Programming” on page 265 con-

tains a detailed description on Flash data serial downloading using the SPI pins or the

JTAG interface.

Constant tables can be allocated within the entire program memory address space (see

the LPM – Load Program Memory instruction description).

Timing diagrams for instruction fetch and execution are presented in “Instruction Execu-

tion Timing” on page 12.

Figure 8. Program Memory Map

0x0000

0x1FFF

Program Memory

Application Flash Section

Boot Flash Section

1 2 ... 10 11 12 13 14 15 16 17 18 19 20 ... 316 317

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Rainbow-electronics Atmega169L Manuel d'utilisateur Page 15