Datasheet

155
ATtiny25/45/85 [DATASHEET]
2586Q–AVR–08/2013
20.6 High-voltage Serial Programming
This section describes how to program and verify Flash Program memory, EEPROM Data memory, Lock bits and
Fuse bits in the ATtiny25/45/85.
Figure 20-3. High-voltage Serial Programming
The minimum period for the Serial Clock Input (SCI) during High-voltage Serial Programming is 220 ns.
20.7 High-voltage Serial Programming Algorithm
To program and verify the ATtiny25/45/85 in the High-voltage Serial Programming mode, the following sequence is
recommended (See instruction formats in Table 20-16):
Table 20-13. Pin Name Mapping
Signal Name in High-voltage
Serial Programming Mode Pin Name I/O Function
SDI PB0 I Serial Data Input
SII PB1 I Serial Instruction Input
SDO PB2 O Serial Data Output
SCI PB3 I Serial Clock Input (min. 220ns period)
Table 20-14. Pin Values Used to Enter Programming Mode
Pin Symbol Value
SDI Prog_enable[0] 0
SII Prog_enable[1] 0
SDO Prog_enable[2] 0
VCC
GND
SDO
SII
SDI
(RESET)
+4.5 - 5.5V
PB0
PB1
PB2
PB5
+11.5 - 12.5V
PB3
SCI