Datasheet

728
11011B–ATARM–21-Feb-12
SAM3N
35.8.5 Two-wire Serial Interface Characteristics
Table 35-43 describes the requirements for devices connected to the Two-wire Serial Bus. For timing symbols refer to Fig-
ure 35-19.
Note: 1. Required only for f
TWCK
> 100 kHz.
2. C
b
= capacitance of one bus line in pF. Per I2C Standard, C
b
Max = 400pF
3. The TWCK low Period is defined as follows:
4.
The TWCK high period is defined as follows:
5. T
CP_MCK
= MCK Bus Period.
Table 35-43. Two-wire Serial Bus Requirements
Symbol Parameter Condition Min Max Units
V
IL
Input Low-voltage -0.3 0.3 V
VDDIO
V
V
IH
Input High-voltage 0.7xV
VDDIO
V
CC
+ 0.3 V
V
hys
Hysteresis of Schmitt Trigger Inputs 0.150 – V
V
OL
Output Low-voltage 3 mA sink current - 0.4 V
t
r
Rise Time for both TWD and TWCK 20 + 0.1C
b
(1)(2)
300 ns
t
of
Output Fall Time from V
IHmin
to V
ILmax
10 pF < C
b
< 400 pF
Figure 35-19
20 + 0.1C
b
(1)(2)
250 ns
C
i
(1)
Capacitance for each I/O Pin – 10 pF
f
TWCK
TWCK Clock Frequency 0 400 kHz
Rp Value of Pull-up resistor
f
TWCK
≤ 100 kHz
f
TWCK
> 100 kHz
t
LOW
Low Period of the TWCK clock
f
TWCK
≤ 100 kHz
(3)
–µs
f
TWCK
> 100 kHz
(3)
–µs
t
HIGH
High period of the TWCK clock
f
TWCK
≤ 100 kHz
(4)
–µs
f
TWCK
> 100 kHz
(4)
–µs
t
HD;STA
Hold Time (repeated) START Condition
f
TWCK
≤ 100 kHz t
HIGH
–µs
f
TWCK
> 100 kHz t
HIGH
–µs
t
SU;STA
Set-up time for a repeated START condition
f
TWCK
≤ 100 kHz t
HIGH
–µs
f
TWCK
> 100 kHz t
HIGH
–µs
t
HD;DAT
Data hold time
f
TWCK
≤ 100 kHz 0 3 x T
CP_MCK
(5)
µs
f
TWCK
> 100 kHz 0 3 x T
CP_MCK
(5)
µs
t
SU;DAT
Data setup time
f
TWCK
≤ 100 kHz
t
LOW -
3 x
T
CP_MCK
(5)
–ns
f
TWCK
> 100 kHz
t
LOW -
3 x
T
CP_MCK
(5)
–ns
t
SU;STO
Setup time for STOP condition
f
TWCK
≤ 100 kHz t
HIGH
–µs
f
TWCK
> 100 kHz t
HIGH
–µs
t
HD;STA
Hold Time (repeated) START Condition
f
TWCK
≤ 100 kHz t
HIGH
–µs
f
TWCK
> 100 kHz t
HIGH
–µs
V
VDDIO
0,4V–
3mA
--------------------------------------
1000ns
C
b
-------------------
Ω
V
VDDIO
0,4V–
3mA
--------------------------------------
300ns
C
b
----------------
Ω
T
low
CLDIV( 2
CKDIV
×()4 )+ T
MCK
×=
T
high
CHDIV( 2
CKDIV
×()4 )+ T
MCK
×=