Datasheet

49
ATtiny11/12
1006D–AVR–07/03
High-voltage Serial
Programming Algorithm
To program and verify the ATtiny11/12 in the High-voltage Serial Programming mode,
the following sequence is recommended (See instruction formats in Table 23):
1. Power-up sequence: Apply 4.5 - 5.5V between V
CC
and GND. Set PB5 and PB0
to “0” and wait at least 100 ns. Toggle PB3 at least four times with minimum 100
ns pulse-width. Set PB3 to “0”. Wait at least 100 ns. Apply 12V to PB5 and wait
at least 100 ns before changing PB0. Wait 8 µs before giving any instructions.
2. The Flash array is programmed one byte at a time by supplying first the address,
then the low and high data byte. The write instruction is self-timed, wait until the
PB2 (RDY/BSY
) pin goes high.
3. The EEPROM array (ATtiny12 only) is programmed one byte at a time by supply-
ing first the address, then the data byte. The write instruction is self-timed, wait
until the PB2 (RDY/BSY
) pin goes high.
4. Any memory location can be verified by using the Read instruction which returns
the contents at the selected address at serial output PB2.
5. Power-off sequence:Set PB3 to “0”.
Set PB5 to “1”.
Turn V
CC
power off.
When writing or reading serial data to the ATtiny11/12, data is clocked on the rising
edge of the serial clock, see Figure 28, Figure 29 and Table 24 for details.