ATmega8 Atmel Corporation, ATmega8 Datasheet - Page 232

• Manufacturer Part Number: ATmega8
• Manufacturer: Atmel Corporation

Specifications of ATmega8

• Flash (kbytes): 8 Kbytes
• Pin Count: 32
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 12
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 23
• Ext Interrupts: 2
• Usb Speed: No
• Usb Interface: No
• Spi: 1
• Twi (i2c): 1
• Uart: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 15
• Analog Comparators: 1
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 1
• Eeprom (bytes): 512
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 2.7 to 5.5
• Operating Voltage (vcc): 2.7 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 3
• Output Compare Channels: 3
• Input Capture Channels: 1
• Pwm Channels: 3
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

Data Polling EEPROM
232
ATmega8(L)
When a new byte has been written and is being programmed into EEPROM, reading the
address location being programmed will give the value 0xFF. At the time the device is ready for
a new byte, the programmed value will read correctly. This is used to determine when the next
byte can be written. This will not work for the value 0xFF, but the user should have the following
in mind: As a chip-erased device contains 0xFF in all locations, programming of addresses that
are meant to contain 0xFF, can be skipped. This does not apply if the EEPROM is Re-pro-
grammed without chip-erasing the device. In this case, data polling cannot be used for the value
0xFF, and the user will have to wait at least t
Table 97
Table 97. Minimum Wait Delay Before Writing the Next Flash or EEPROM Location
Figure 113. Serial Programming Waveforms
Symbol
t
t
t
t
WD_FUSE
WD_FLASH
WD_EEPROM
WD_ERASE
SERIAL DATA OUTPUT
SERIAL CLOCK INPUT
SERIAL DATA INPUT
for t
WD_EEPROM
SAMPLE
(MOSI)
(MISO)
(SCK)
value.
MSB
MSB
WD_EEPROM
Minimum Wait Delay
before programming the next byte. See
4.5ms
4.5ms
9.0ms
9.0ms
LSB
LSB
2486Z–AVR–02/11