atmega161-4pi ATMEL Corporation, atmega161-4pi Datasheet - Page 127

• Manufacturer Part Number: atmega161-4pi
• Description: 8-bit Microcontroller With 16k Bytes Of In-system Programmable Flash
• Manufacturer: ATMEL Corporation

Data Polling EEPROM
1228D–AVR–02/07
t
all locations, programming of addresses that are meant to contain $FF can be skipped.
See Table 46 for t
When a new byte has been written and is being programmed into EEPROM, reading the
address location being programmed will give the value $FF. At the time the device is
ready for a new byte, the programmed value will read correctly. This is used to deter-
mine when the next byte can be written. This will not work for the value $FF, but the user
should keep the following in mind: As a chip-erased device contains $FF in all locations,
programming of addresses that are meant to contain $FF can be skipped. This does not
apply if the EEPROM is reprogrammed without chip-erasing the device. In this case,
data polling cannot be used for the value $FF, and the user will have to wait at least
t
Table 46. Minimum Wait Delay before Writing the Next Flash or EEPROM Location
Table 47. Minimum Wait Delay after a Chip Erase Command
Figure 80. Serial Programming Waveforms
WD_FLASH
WD_EEPROM
Symbol
t
t
Symbol
t
WD_FLASH
WD_EEPROM
WD_ERASE
SERIAL DATA OUTPUT
SERIAL CLOCK INPUT
SERIAL DATA INPUT
before programming the next page. As a chip-erased device contains $FF in
PB5 (MOSI)
PB6 (MISO)
before programming the next byte. See Table 46 for t
PB7(SCK)
SAMPLE
WD_FLASH
MSB
MSB
value.
Minimum Wait Delay
Minimum Wait Delay
28 ms
3.4 ms
14 ms
ATmega161(L)
WD_EEPROM
value.
LSB
LSB
127