ATtiny15L
50
High-voltage Serial Programming Algorithm
To program and verify the ATtiny15L in the high-voltage serial programming mode, the following sequence is recom-
mended (See instruction formats in Table 24):
1.
Power-up sequence:
Apply 4.5 - 5.5V between VCC and GND. Set PB5 and PB0 to “0” and wait at least 30 µs.
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 is programmed one-byte at a time by supplying 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 “0”.
Turn VCC power-off.
When writing or reading serial data to the ATtiny15L, data is clocked on the 8th rising edge of the 16 external clock pulses
needed to generate the internal clock. See Figure 31, Figure 32 and Table 25 for an explanation.
Figure 31.
High-voltage Serial Programming Waveforms
MSB
MSB
MSB
LSB
LSB
LSB
0
1
2
3
4
5
6
7
8
9
10
SERIAL DATA INPUT
PB0
SERIAL INSTR. INPUT
PB1
SERIAL DATA OUTPUT
PB2
INTERNAL CK
SERIAL CLOCK INPUT
PB3
16x
