143
7598H–AVR–07/09
ATtiny25/45/85
Figure 21-4. High-voltage Serial Programming
Table 21-12. 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 21-13. High-voltage Serial Programming Characteristics T
A
= 25°C ±10%,
V
CC
= 5.0V ±10% (Unless otherwise noted)
Symbol
Parameter
Min
Typ
Max
Units
t
SHSL
SCI (PB3) Pulse Width High
125
ns
t
SLSH
SCI (PB3) Pulse Width Low
125
ns
t
IVSH
SDI (PB0), SII (PB1) Valid to SCI (PB3) High
50
ns
t
SHIX
SDI (PB0), SII (PB1) Hold after SCI (PB3)
High
50
ns
t
SHOV
SCI (PB3) High to SDO (PB2) Valid
16
ns
t
WLWH_PFB
Wait after Instr. 3 for Write Fuse Bits
2.5
ms
Table 21-14. 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