Техническая Спецификация для Atmel Evaluation Kit AT91SAM9X25-EK AT91SAM9X25-EK
Модели
AT91SAM9X25-EK
1123
SAM9X25 [DATASHEET]
11054E–ATARM–10-Mar-2014
46.19 Two-wire Interface Characteristics
describes the requirements for devices connected to the Two-wire Serial Bus.
.
Notes: 1. Required only for f
TWCK
> 100 kHz.
2. C
b
= capacitance of one bus line in pF. Per I2C Standard, C
b
Max = 400 pF
3. The TWCK low period is defined
as follows:
t
low
= ((CLDIV
× 2
CKDIV
) + 4)
× t
MCK
4. The TWCK high period is defined as follows: t
high
= ((CHDIV
× 2
CKDIV
) + 4
× t
MCK
5. t
CP_MCK
= MCK bus period.
Table 46-47. Two-wire Serial Bus Requirements
Symbol
Parameter
Conditions
Min
Max
Unit
V
IL
Input Low-voltage
—
-0.3
0.3
× V
DDIO
V
V
IH
Input High-voltage
—
0.7
× V
DDIO
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
300
ns
t
OF
Output Fall Time from V
IHmin
to V
ILmax
10 pF < C
b
< 400 pF
(
)
20 + 0.1C
b
250
ns
C
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
(V
DDIO
- 0.4V)
÷ 3mA
1000ns
÷ C
b
Ω
f
TWCK
> 100 kHz
(V
DDIO
- 0.4V)
÷ 3mA
300ns
÷ C
b
Ω
t
LOW
Low Period of the TWCK Clock
f
TWCK
≤ 100 kHz
—
µ
s
f
TWCK
> 100 kHz
—
µ
s
t
HIGH
High Period of the TWCK Clock
f
TWCK
≤ 100 kHz
—
µ
s
f
TWCK
> 100 kHz
—
µ
s
t
HD;STA
Hold Time (repeated) START condition
f
TWCK
≤ 100 kHz
t
HIGH
—
µ
s
f
TWCK
> 100 kHz
t
HIGH
—
µ
s
t
SU;STA
Set-up Time for a repeated START
condition
condition
f
TWCK
≤ 100 kHz
t
HIGH
—
µ
s
f
TWCK
> 100 kHz
t
HIGH
—
µ
s
t
HD;DAT
Data Hold Time
f
TWCK
≤ 100 kHz
0
3
× t
CP_MCK
µ
s
f
TWCK
> 100 kHz
0
3
× t
CP_MCK
µ
s
t
SU;DAT
Data Setup Time
f
TWCK
≤ 100 kHz
t
LOW
- 3
× t
CP_MCK
—
ns
f
TWCK
> 100 kHz
t
LOW
- 3
× t
CP_MCK
—
ns
t
SU;STO
Setup Time for STOP condition
f
TWCK
≤ 100 kHz
t
HIGH
—
µ
s
f
TWCK
> 100 kHz
t
HIGH
—
µ
s
t
HD;STA
Bus free time between a STOP and START
condition
condition
f
TWCK
≤ 100 kHz
t
HIGH
—
µ
s
f
TWCK
> 100 kHz
t
HIGH
—
µ
s