ATTINY25-15SZ Datasheet, PDF (137/196 Pages) ATMEL Corporation – 8-bit Microcontroller with 2/4/8K Bytes In-System Programmable Flash

ATtiny25/45/85
21.3
Signature Bytes
All Atmel microcontrollers have a three-byte signature code which identifies the device. This
code can be read in both serial and High-voltage Programming mode, also when the device is
locked. The three bytes reside in a separate address space.
21.3.1
ATtiny25 Signature Bytes
1. 0x000: 0x1E (indicates manufactured by Atmel).
2. 0x001: 0x91 (indicates 2 KB Flash memory).
3. 0x002: 0x08 (indicates ATtiny25 device when 0x001 is 0x91).
21.3.2
ATtiny45 Signature Bytes
1. 0x000: 0x1E (indicates manufactured by Atmel).
2. 0x001: 0x92 (indicates 4 KB Flash memory).
3. 0x002: 0x06 (indicates ATtiny45 device when 0x001 is 0x92).
21.3.3
ATtiny85 Signature Bytes
1. 0x000: 0x1E (indicates manufactured by Atmel).
2. 0x001: 0x93 (indicates 8 KB Flash memory).
3. 0x002: 0x0B (indicates ATtiny85 device when 0x001 is 0x93).
21.4
Calibration Byte
Signature area of the ATtiny25/45/85 has one byte of calibration data for the internal RC Oscilla-
tor. This byte resides in the high byte of address 0x000. During reset, this byte is automatically
written into the OSCCAL Register to ensure correct frequency of the calibrated RC Oscillator.
21.5 Page Size
Table 21-6.
Device
ATtiny25
ATtiny45
ATtiny85
No. of Words in a Page and No. of Pages in the Flash
Flash Size Page Size PCWORD No. of Pages
1K words
(2K bytes)
16 words
PC[3:0]
64
2K words
(4K bytes)
32 words
PC[4:0]
64
4K words
(8K bytes)
32 words
PC[4:0]
128
PCPAGE
PC[9:4]
PC[10:5]
PC[11:5]
PCMSB
9
10
11
Table 21-7.
Device
ATtiny25
ATtiny45
ATtiny85
No. of Words in a Page and No. of Pages in the EEPROM
EEPROM
Size
Page Size
PCWORD
No. of Pages
PCPAGE
128 bytes
4 bytes
EEA[1:0]
32
EEA[6:2]
256 bytes
4 bytes
EEA[1:0]
64
EEA[7:2]
512 bytes
4 bytes
EEA[1:0]
128
EEA[8:2]
EEAMSB
6
7
8
7598I–AVR–10/12
137