attiny25v ATMEL Corporation, attiny25v Datasheet - Page 154

• Manufacturer Part Number: attiny25v
• Description: Microcontroller With 2/4/8k Bytes In-system Programmable Flash
• Manufacturer: ATMEL Corporation

20.3.1
20.3.2
20.4
154
Page Size
ATtiny25/45/85
Signature Bytes
Calibration 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, even when the device is
locked.
Signature bytes can also be read by the device firmware. See section
Signature Data from Software” on page
The three signature bytes reside in a separate address space called the device signature imprint
table. The signature data for ATtiny25/45/85 is given in
Table 20-7.
The device signature imprint table of ATtiny25/45/85 contains two bytes of calibration data for
the internal RC Oscillator, as shown in
calibration data for 9.6 MHz operation is automatically fetched and written to the OSCCAL regis-
ter during reset. In ATtiny15 compatibility mode the calibraiton data for 4.8 MHz operation is
used instead. This procedure guarantees the internal oscillator is always calibrated to the cor-
rect frequency.
Calibration bytes can also be read by the device firmware. See section
Signature Data from Software” on page
Table 20-8.
Table 20-9.
Part
ATtiny25
ATtiny45
ATtiny85
ATtiny25
ATtiny45
ATtiny85
ATtiny25
ATtiny45
ATtiny85
Device
Device
Device Signature Bytes
No. of Words in a Page and No. of Pages in the Flash
No. of Words in a Page and No. of Pages in the EEPROM
EEPROM
128 bytes
256 bytes
512 bytes
1K words
(2K bytes)
2K words
(4K bytes)
4K words
(8K bytes)
Flash Size
Size
Signature Byte 0
Page Size
4 bytes
4 bytes
4 bytes
Page Size
16 words
32 words
32 words
0x1E
0x1E
0x1E
Table 20-6 on page
147.
147.
PCWORD
EEA[1:0]
EEA[1:0]
EEA[1:0]
PCWORD
PC[3:0]
PC[4:0]
PC[4:0]
Signature Byte 1
Table
No. of Pages
0x91
0x92
0x93
No. of Pages
153. In normal mode of operation the
128
32
64
20-7.
128
64
64
“Reading Lock, Fuse and
“Reading Lock, Fuse and
PCPAGE
EEA[6:2]
EEA[7:2]
EEA[8:2]
PCPAGE
PC[10:5]
PC[11:5]
PC[9:4]
Signature Byte 0
0x08
0x06
0x0B
2586K–AVR–01/08
EEAMSB
PCMSB
6
7
8
10
11
9