Datasheet

163
ATtiny2313/V
2543H–AVR–02/05
Serial Programming Pin
Mapping
Parallel Programming
Enter Programming Mode The following algorithm puts the device in Parallel programming mode:
1. Set Prog_enable pins listed in Table 72 on page 162 to “0000”, RESET pin V
CC
to 0V.
2. Apply 4.5 - 5.5V between V
CC
and GND.
3. Ensure that V
CC
reaches at least 1.8V within the next 20 µs.
4. Wait 20 - 60 µs, and apply 11.5 - 12.5V to RESET.
5. Keep the Prog_enable pins unchanged for at least 10µs after the High-voltage
has been applied to ensure the Prog_enable Signature has been latched.
6. Wait at least 300 µs before giving any parallel programming commands.
7. Exit Programming mode by power the device down or by bringing RESET pin to
0V.
If the rise time of the V
CC
is unable to fulfill the requirements listed above, the following
alternative algorithm can be used.
1. Set Prog_enable pins listed in Table 72 on page 162 to “0000”, RESET pin to 0V
and V
CC
to 0V.
2. Apply 4.5 - 5.5V between V
CC
and GND.
3. Monitor V
CC
, and as soon as V
CC
reaches 0.9 - 1.1V, apply 11.5 - 12.5V to
RESET.
4. Keep the Prog_enable pins unchanged for at least 10µs after the High-voltage
has been applied to ensure the Prog_enable Signature has been latched.
5. Wait until V
CC
actually reaches 4.5 -5.5V before giving any parallel programming
commands.
6. Exit Programming mode by power the device down or by bringing RESET pin to
0V.
Considerations for Efficient
Programming
The loaded command and address are retained in the device during programming. For
efficient programming, the following should be considered.
• The command needs only be loaded once when writing or reading multiple memory
locations.
• Skip writing the data value 0xFF, that is the contents of the entire EEPROM (unless
the EESAVE Fuse is programmed) and Flash after a Chip Erase.
• Address high byte needs only be loaded before programming or reading a new 256
word window in Flash or 256 byte EEPROM. This consideration also applies to
Signature bytes reading.
Chip Erase The Chip Erase will erase the Flash and EEPROM
(1)
memories plus Lock bits. The Lock
bits are not reset until the program memory has been completely erased. The Fuse bits
Table 75. Pin Mapping Serial Programming
Symbol Pins I/O Description
MOSI PB5 I Serial Data in
MISO PB6 O Serial Data out
SCK PB7 I Serial Clock