ATMEGA8_08 Datasheet, PDF (239/308 Pages) ATMEL Corporation – 8-bit with 8K Bytes In-System Programmable Flash

ATmega8(L)
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_{WD_EEPROM} before programming the next byte. See
Table 97 for t_{WD_EEPROM} value.
Table 97. Minimum Wait Delay Before Writing the Next Flash or EEPROM Location
Symbol
Minimum Wait Delay
t_{WD_FUSE}
t_{WD_FLASH}
t_{WD_EEPROM}
t_{WD_ERASE}
4.5 ms
4.5 ms
9.0 ms
9.0 ms
Figure 113. Serial Programming Waveforms
SERIAL DATA INPUT
MSB
LSB
(MOSI)
SERIAL DATA OUTPUT
MSB
LSB
(MISO)
SERIAL CLOCK INPUT
(SCK)
SAMPLE
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