Datasheet

252
ATtiny828 [DATASHEET]
8371A–AVR–08/12
24.7 Two-Wire Serial Interface Characteristics
The following data is based on simulations and characterisations. Parameters listed in Table 111 on page 252 are not tested in
production. Symbols refer to Figure 103.
Table 111. Two-Wire Serial Interface Characteristics
Notes: 1. f
CK
= CPU clock frequency.
Figure 103. Two-Wire Serial Bus Timing
Symbol Parameter Condition Min Max
Uni
t
VIL
Input Low voltage -0.5 0.3 V
CC
V
VIH
Input High voltage 0.7 V
CC
V
CC
+ 0.5 V
VHYS
Hysteresis of Schmitt-trigger inputs
V
CC
> 2.7V 0.05 V
CC
–
V
V
CC
< 2.7V 0
VOL
Output Low voltage
I
OL
= 3mA, V
CC
> 2.7V
0 0.4
V
I
OL
= 2mA, V
CC
< 2.7V
tSP
Spikes suppressed by input filter 0 50 ns
f
SCL
SCL clock frequency
(1)
0 400 kHz
t
HD:STA
Hold time (repeated) START Condition 0.6 – µs
t
LOW
Low period of SCL clock 1.3 – µs
t
HIGH
High period of SCL clock 0.6 – µs
t
SU:STA
Set-up time for repeated START condition 0.6 – µs
t
HD:DAT
Data hold time 0 0.9 µs
t
SU:DAT
Data setup time 100 – ns
t
SU:STO
Setup time for STOP condition 0.6 – µs
t
BUF
Bus free time between STOP and START
condition
1.3 – µs
t
SU:STA
t
LOW
t
HIGH
t
LOW
t
OF
t
HD:STA
t
HD:DAT
t
SU:DAT
t
SU:STO
t
BUF
SCL
SDA
t
R