ATA8742 ATMEL Corporation, ATA8742 Datasheet - Page 31

• Manufacturer Part Number: ATA8742
• Manufacturer: ATMEL Corporation

13. Memories
13.1
13.2
9151A–INDCO–07/09
In-System Re-programmable Flash Program Memory
SRAM Data Memory
This section describes the different memories in the ATtiny24/44/84. The AVR architecture has
two main memory spaces, the Data memory and the Program memory space. In addition, the
ATtiny24/44/84 features an EEPROM Memory for data storage. All three memory spaces are lin-
ear and regular.
The ATtiny24/44/84 contains 2/4/8K byte 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
1024/2048/4096 x 16.
The Flash memory has an endurance of at least 10,000 write/erase cycles. The ATtiny24/44/84
Program Counter (PC) is 10/11/12 bits wide, thus addressing the 1024/2048/4096 Program
memory locations.
data serial downloading using the SPI pins.
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
ing” on page
Figure 13-1. Program Memory Map
Figure 13-2 on page 32
The lower 160 Data memory locations address both the Register File, the I/O memory and the
internal data SRAM. The first 32 locations address the Register File, the next 64 locations the
standard I/O memory, and the last 128/256/512 locations address the internal data SRAM.
The five different addressing modes for the Data memory cover: Direct, Indirect with Displace-
ment, Indirect, Indirect with Pre-decrement, and Indirect with Post-increment. In the Register
File, registers R26 to R31 feature the indirect addressing pointer registers.
The direct addressing reaches the entire data space.
The Indirect with Displacement mode reaches 63 address locations from the base address given
by the Y- or Z-register.
28.
“Memory Programming” on page 180
shows how the ATtiny24/44/84 SRAM Memory is organized.
Program Memory
0x03FF/0x07FF/0xFFF
0x0000
contains a detailed description on Flash
“Instruction Execution Tim-
ATA8742
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