atmega163l ATMEL Corporation, atmega163l Datasheet - Page 156

• Manufacturer Part Number: atmega163l
• Description: Atmega163 8-bit Avr Microcontroller With 16k Bytes Of In-system Programmable Flash
• Manufacturer: ATMEL Corporation

Data Polling Flash
Data Polling EEPROM
Programming Times for Non-
volatile Memory
156
ATmega163(L)
When a page is being programmed into the Flash, reading an address location within
the page being programmed will give the value $FF. At the time the device is ready for a
new page, the programmed value will read correctly. This is used to determine when the
next page can be written. Note that the entire page is written simultaneously and any
address within the page can be used for polling. Data polling of the Flash will not work
for the value $FF, so when programming this value, the user will have to wait for at least
t
all locations, programming of addresses that are meant to contain $FF, can be skipped.
See Table 60 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 have 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 re-programmed 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
The internal RC Oscillator is used to control programming time when programming or
erasing Flash, EEPORM, Fuses, and Lock bits. During Parallel or Serial Programming,
the device is in reset, and this Oscillator runs at its initial, uncalibrated frequency, which
may vary from 0.5 MHz to 1.0 MHz. In software it is possible to calibrate this Oscillator to
1.0 MHz (see “Calibrated Internal RC Oscillator” on page 37). Consequently, program-
ming times will be shorter and more accurate when Programming or erasing non-volatile
memory from software, using SPM or the EEPROM interface. See Table 60 for a sum-
mary of programming times.
Table 60. Maximum Programming Times for Non-volatile Memory
Notes:
WD_FLASH
Operation
Chip Erase
Flash
Write
EEPROM
Write
Fuse/lock bit
write
WD_EEPROM
(3)
(2)
1. Includes variation over voltage and temperature after RC Oscillator has been cali-
2. Parallel EEPROM Programming takes 1K cycles
3. Per page
before programming the next page. As a chip-erased device contains $FF in
brated to 1.0 MHz
Symbol
t
t
t
t
WD_CE
WD_FLASH
WD_EEPROM
WD_FUSE
before programming the next byte. See Table 60 for t
WD_FLASH
value.
Number of
Oscillator
Cycles
16K
RC
8K
2K
1K
32 ms
16 ms
4 ms
2 ms
2.7V
Parallel/Serial
Programming
3.8 ms
1.9 ms
30 ms
15 ms
5.0V
WD_EEPROM
Programming
1142E–AVR–02/03
8.5 ms
2.2 ms
1.1 ms
17 ms
Self-
value.
(1)