attiny261a-xu ATMEL Corporation, attiny261a-xu Datasheet - Page 16

• Manufacturer Part Number: attiny261a-xu
• Description: 8-bit Avr Microcontroller With 2/4/8k Bytes In-system Programmable Flash
• Manufacturer: ATMEL Corporation

5.2.1
5.3
16
EEPROM Data Memory
ATtiny261A/461A/861A
Data Memory Access Times
When using register indirect addressing modes with automatic pre-decrement and post-incre-
ment, the address registers X, Y, and Z are decremented or incremented.
The 32 general purpose working registers, 64 I/O Registers, and the 128/256/512 bytes of inter-
nal data SRAM in the ATtiny261A/461A/861A are all accessible through all these addressing
modes. The Register File is described in
Figure 5-2.
This section describes the general access timing concepts for internal memory access. The
internal data SRAM access is performed in two clk
Figure 5-3.
The ATtiny261A/461A/861A contains 128/256/512 bytes of data EEPROM memory. It is orga-
nized as a separate data space, in which single bytes can be read and written. The EEPROM
has an endurance of at least 100,000 write/erase cycles. The access between the EEPROM and
the CPU is described in the following, specifying the EEPROM Address Registers, the EEPROM
Data Register, and the EEPROM Control Register. For a detailed description of Serial data
downloading to the EEPROM, see
Address
clk
Data Memory Map
On-chip Data SRAM Access Cycles
Data
Data
WR
CPU
RD
Compute Address
(128/256/512 x 8)
64 I/O Registers
Data Memory
Internal SRAM
32 Registers
T1
Memory Access Instruction
“Electrical Characteristics” on page
“General Purpose Register File” on page
Address valid
CPU
0x0DF/0x15F/0x25F
0x0000 - 0x001F
0x0020 - 0x005F
0x0060
T2
cycles as illustrated in
Next Instruction
T3
184.
Figure
8197B–AVR–01/10
10.
5-3.