Technical data

MCIMX31C/MCIMX31LC Technical Data, Rev. 4.3
50 Freescale Semiconductor
Electrical Characteristics
4.3.13 I
2
C Electrical Specifications
This section describes the electrical information of the I
2
C Module.
4.3.13.1 I
2
C Module Timing
Figure 41 depicts the timing of I
2
C module. Table 40 lists the I
2
C module timing parameters where the I/O
supply is 2.7 V. 1
Figure 41. I
2
C Bus Timing Diagram
Table 40. I
2
C Module Timing Parameters—I
2
C Pin I/O Supply=2.7 V
ID Parameter
Standard Mode Fast Mode
Unit
Min Max Min Max
IC1 I2CLK cycle time 10 — 2.5 — μs
IC2 Hold time (repeated) START condition 4.0 — 0.6 — μs
IC3 Set-up time for STOP condition 4.0 — 0.6 — μs
IC4 Data hold time 0
1
1
A device must internally provide a hold time of at least 300 ns for I2DAT signal in order to bridge the undefined region of the
falling edge of I2CLK.
3.45
2
2
The maximum hold time has to be met only if the device does not stretch the LOW period (ID IC6) of the I2CLK signal.
0
1
0.9
2
μs
IC5 HIGH Period of I2CLK Clock 4.0 — 0.6 — μs
IC6 LOW Period of the I2CLK Clock 4.7 — 1.3 — μs
IC7 Set-up time for a repeated START condition 4.7 — 0.6 — μs
IC8 Data set-up time 250 — 100
3
3
A Fast-mode I
2
C-bus device can be used in a standard-mode I
2
C-bus system, but the requirement of set-up time (ID IC7) of
250 ns must then be met. This will automatically be the case if the device does not stretch the LOW period of the I2CLK signal.
If such a device does stretch the LOW period of the I2CLK signal, it must output the next data bit to the I2DAT line max_rise_time
(ID No IC10) + data_setup_time (ID No IC8) = 1000 + 250 = 1250 ns (according to the Standard-mode I
2
C-bus specification)
before the I2CLK line is released.
—ns
IC9 Bus free time between a STOP and START condition 4.7 — 1.3 — μs
IC10 Rise time of both I2DAT and I2CLK signals — 1000 20+0.1C
b
4
4
C
b
= total capacitance of one bus line in pF.
300 ns
IC11 Fall time of both I2DAT and I2CLK signals — 300 20+0.1C
b
4
300 ns
IC12 Capacitive load for each bus line (C
b
) — 400 — 400 pF
IC10
IC11
IC9
IC2
IC8
IC4
IC7
IC3
IC6
IC10
IC5
IC11
START
STOP START
START
I2DAT
I2CLK
IC1