attiny25v ATMEL Corporation, attiny25v Datasheet - Page 159

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

20.7
20.7.1
2586K–AVR–01/08
High-voltage Serial Programming Algorithm
Enter High-voltage Serial Programming Mode
Figure 20-3. High-voltage Serial Programming
Table 20-13. Pin Name Mapping
The minimum period for the Serial Clock Input (SCI) during High-voltage Serial Programming is
220 ns.
Table 20-14. Pin Values Used to Enter Programming Mode
To program and verify the ATtiny25/45/85 in the High-voltage Serial Programming mode, the fol-
lowing sequence is recommended (See instruction formats in
The following algorithm puts the device in High-voltage Serial Programming mode:
Signal Name in High-voltage
Serial Programming Mode
SDI
SII
SDO
SCI
Pin
SDI
SII
SDO
1. Set Prog_enable pins listed in
2. Apply 4.5 - 5.5V between V
the next 20 µs.
SCI
+11.5 - 12.5V
Symbol
Prog_enable[0]
Prog_enable[1]
Prog_enable[2]
CC
PB5
PB3
GND
and GND. Ensure that V
Table 20-14
Pin Name
PB0
PB1
PB2
PB3
(RESET)
to “000”, RESET pin and V
I/O
I
I
O
I
VCC
PB2
PB1
PB0
Function
Serial Data Input
Serial Instruction Input
Serial Data Output
Serial Clock Input (min. 220ns period)
CC
+4.5 - 5.5V
Table
reaches at least 1.8V within
ATtiny25/45/85
20-16):
SDO
SII
SDI
CC
to 0V.
Value
0
0
0
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