attiny25v ATMEL Corporation, attiny25v Datasheet - Page 160

• Manufacturer Part Number: attiny25v
• Description: Microcontroller With 2/4/8k Bytes In-system Programmable Flash
• Manufacturer: ATMEL Corporation

20.7.2
20.7.3
160
ATtiny25/45/85
Considerations for Efficient Programming
Chip Erase
If the rise time of the V
tive algorithm can be used:
Table 20-15. High-voltage Reset Characteristics
The loaded command and address are retained in the device during programming. For efficient
programming, the following should be considered.
The Chip Erase will erase the Flash and EEPROM
not reset until the Program memory has been completely erased. The Fuse bits are not
Supply Voltage
V
4.5V
5.5V
3. Wait 20 - 60 µs, and apply 11.5 - 12.5V to RESET.
4. Keep the Prog_enable pins unchanged for at least 10 µs after the High-voltage has
5. Release the Prog_enable[2] pin to avoid drive contention on the Prog_enable[2]/SDO
6. Wait at least 300 µs before giving any serial instructions on SDI/SII.
7. Exit Programming mode by power the device down or by bringing RESET pin to 0V.
1. Set Prog_enable pins listed in
2. Apply 4.5 - 5.5V between V
3. Monitor V
4. Keep the Prog_enable pins unchanged for at least 10 µs after the High-voltage has
5. Release the Prog_enable[2] pin to avoid drive contention on the Prog_enable[2]/SDO
6. Wait until V
7. Exit Programming mode by power the device down or by bringing RESET pin to 0V.
• The command needs only be loaded once when writing or reading multiple memory
• Skip writing the data value 0xFF that is the contents of the entire EEPROM (unless the
• Address High byte needs only be loaded before programming or reading a new 256 word
CC
locations.
EESAVE Fuse is programmed) and Flash after a Chip Erase.
window in Flash or 256 byte EEPROM. This consideration also applies to Signature bytes
reading.
been applied to ensure the Prog_enable Signature has been latched.
pin.
been applied to ensure the Prog_enable Signature has been latched.
pin.
SDI/SII.
CC
CC
, and as soon as V
actually reaches 4.5 - 5.5V before giving any serial instructions on
RESET Pin High-voltage Threshold
CC
is unable to fulfill the requirements listed above, the following alterna-
CC
V
and GND.
Table 20-14
11.5V
11.5V
CC
HVRST
reaches 0.9 - 1.1V, apply 11.5 - 12.5V to RESET.
to “000”, RESET pin and V
(1)
memories plus Lock bits. The Lock bits are
Minimum High-voltage Period for
Latching Prog_enable
100 ns
100 ns
t
HVRST
CC
to 0V.
2586K–AVR–01/08