ATMEGA8_14 Datasheet, PDF (218/331 Pages) ATMEL Corporation – High-performance, Low-power Atmel

ATmega8(L)
Signature Bytes
Calibration Byte
Page Size
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)
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 1MHz, 2MHz, 4MHz, and 8Mhz respectively. During Reset, the 1MHz 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
4K words (8 Kbytes)
32 words
PC[4:0]
128
PC[11:5]
PCMSB
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
512 bytes
4 bytes
EEA[1:0]
128
EEA[8:2]
EEAMSB
8
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