198
TMS320C6670 Peripheral Information and Electrical Specifications
Copyright 2012 Texas Instruments Incorporated
SPRS689D—March 2012
Multicore Fixed and Floating-Point System-on-Chip
TMS320C6670
7.12.3 I
2
C Electrical Data/Timing
7.12.3.1 Inter-Integrated Circuits (I
2
C) Timing
Figure 7-36
I
2
C Receive Timings
Table 7-66
I
2
C Timing Requirements
(1)
(see
1 The I
2
C pins SDA and SCL do not feature fail-safe I/O buffers. These pins could potentially draw current when the device is powered down
No.
Standard Mode
Fast Mode
Units
Min
Max
Min
Max
1 t
c(SCL)
Cycle time, SCL
10
2.5
μs
2
t
su(SCLH-SDAL)
Setup time, SCL high before SDA low (for a repeated START
condition)
4.7
0.6
μs
3
t
h(SDAL-SCLL)
Hold time, SCL low after SDA low (for a START and a repeated
START condition)
4
0.6
μs
4 t
w(SCLL)
Pulse duration, SCL low
4.7
1.3
μs
5 t
w(SCLH)
Pulse duration, SCL high
4
0.6
μs
6 t
su(SDAV-SCLH)
Setup time, SDA valid before SCL high
250
100
(2)
2 A Fast-mode I
2
C-bus™ device can be used in a Standard-mode I
2
C-bus™ system, but the requirement tsu(SDA-SCLH)
≥
250 ns must then be met. This will automatically be the
case if the device does not stretch the LOW period of the SCL signal. If such a device does stretch the LOW period of the SCL signal, it must output the next data bit to the
SDA line t
r
max + t
su(SDA-SCLH)
= 1000 + 250 = 1250 ns (according to the Standard-mode I
2
C-Bus Specification) before the SCL line is released.
ns
7 t
h(SCLL-SDAV)
Hold time, SDA valid after SCL low (for I
2
C bus devices)
0
(3)
3 A device must internally provide a hold time of at least 300 ns for the SDA signal (referred to the V
IHmin
of the SCL signal) to bridge the undefined region of the falling edge
of SCL.
3.45
0.9
(4)
4 The maximum t
h(SDA-SCLL)
has to be met only if the device does not stretch the low period [t
w(SCLL)
] of the SCL signal.
μs
8 t
w(SDAH)
Pulse duration, SDA high between STOP and START conditions
4.7
1.3
μs
9 t
r(SDA)
Rise time, SDA
1000
20 + 0.1C
b
(5)
5 C
b
= total capacitance of one bus line in pF. If mixed with HS-mode devices, faster fall-times are allowed.
300
ns
10 t
r(SCL)
Rise time, SCL
1000
20 + 0.1C
300
ns
11 t
f(SDA)
Fall time, SDA
300
20 + 0.1C
300
ns
12 t
f(SCL)
Fall time, SCL
300
20 + 0.1C
300
ns
13 t
su(SCLH-SDAH)
Setup time, SCL high before SDA high (for STOP condition)
4
0.6
μs
14 t
w(SP)
Pulse duration, spike (must be suppressed)
0
50
ns
C
Capacitive load for each bus line
400
400
pF
End of Table 7-66
10
8
4
3
7
12
5
6
14
2
3
13
Stop
Start
Repeated
Start
Stop
SDA
SCL
1
11
9
Содержание TMS320C6670
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