ATmega8(L)
Signature Bytes
All Atmel microcontrollers have a 3-byte signature code which identifies the device. This code
can be read in both Serial and Parallel mode, also when the device is locked. The three bytes
reside in a separate address space.
For the ATmega8 the signature bytes are:
1. 0x000: 0x1E (indicates manufactured by Atmel).
2. 0x001: 0x93 (indicates 8KB Flash memory).
3. 0x002: 0x07 (indicates ATmega8 device).
Calibration Byte
Page Size
The ATmega8 stores four different calibration values for the internal RC Oscillator. These bytes
resides in the signature row High byte of the addresses 0x0000, 0x0001, 0x0002, and 0x0003
for 1, 2, 4, and 8 Mhz respectively. During Reset, the 1 MHz value is automatically loaded into
the OSCCAL Register. If other frequencies are used, the calibration value has to be loaded
manually, see “Oscillator Calibration Register – OSCCAL” on page 31 for details.
Table 89. No. of Words in a Page and no. of Pages in the Flash
Flash Size
Page Size
PCWORD
No. of Pages
PCPAGE
PCMSB
4K words (8K bytes)
32 words
PC[4:0]
128
PC[11:5]
11
Table 90. No. of Words in a Page and no. of Pages in the EEPROM
EEPROM Size
Page Size
PCWORD
No. of Pages
PCPAGE
EEAMSB
512 bytes
4 bytes
EEA[1:0]
128
EEA[8:2]
8
225
2486T–AVR–05/08
ATMEL [ ATMEL ]
