Datasheet

113
XMEGA A4U [DATASHEET]
Atmel-8387H-AVR-ATxmega16A4U-34A4U-64A4U-128A4U-Datasheet_09/2014
36.2.16 Two-Wire Interface Characteristics
Table 36-64 describes the requirements for devices connected to the Two-Wire Interface Bus. The Atmel AVR
XMEGA Two-Wire Interface meets or exceeds these requirements under the noted conditions. Timing symbols refer
to Figure 36-14.
Figure 36-14. Two-wire interface bus timing.
Table 36-64. Two-wire interface characteristics.
t
HD;STA
t
of
SDA
SCL
t
LOW
t
HIGH
t
SU;STA
t
BUF
t
r
t
HD;DAT
t
SU;DAT
t
SU;STO
Symbol Parameter Condition Min. Typ. Max. Units
V
IH
Input high voltage 0.7V
CC
V
CC
+0.5 V
V
IL
Input low voltage 0.5 0.3×V
CC
V
V
hys
Hysteresis of Schmitt trigger inputs 0.05V
CC
(1)
V
V
OL
Output low voltage 3mA, sink current 0 0.4 V
t
r
Rise time for both SDA and SCL 20+0.1C
b
(1)(2)
300 ns
t
of
Output fall time from V
IHmin
to V
ILmax
10pF < C
b
< 400pF
(2)
20+0.1C
b
(1)(2)
250 ns
t
SP
Spikes suppressed by Input filter 0 50 ns
I
I
Input current for each I/O Pin 0.1V
CC
< V
I
< 0.9V
CC
-10 10 µA
C
I
Capacitance for each I/O Pin 10 pF
f
SCL
SCL clock frequency f
PER
(3)
>max(10f
SCL
, 250kHz) 0 400 kHz
R
P
Value of pull-up resistor
f
SCL
≤ 100kHz
Ω
f
SCL
> 100kHz
t
HD;STA
Hold time (repeated) START condition
f
SCL
≤ 100kHz 4.0
µs
f
SCL
> 100kHz 0.6
t
LOW
Low period of SCL Clock
f
SCL
≤ 100kHz 4.7
µs
f
SCL
> 100kHz 1.3
t
HIGH
High period of SCL Clock
f
SCL
≤ 100kHz 4.0
µs
f
SCL
> 100kHz 0.6
t
SU;STA
Set-up time for a repeated START
condition
f
SCL
≤ 100kHz 4.7
µs
f
SCL
> 100kHz 0.6
V
CC
0.4V–
3mA
--------------------------- -
100ns
C
b
-------------- -
300ns
C
b
-------------- -