i.MX25 Applications Processor for Consumer and Industrial Products, Rev. 10
92
Freescale Semiconductor
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.
2 The maximum hold time has only to be met if the device does not stretch the LOW period (ID no IC5) of the I2CLK signal
3 A Fast-mode I2C-bus device can be used in a Standard-mode I2C-bus system, but the requirement of Set-up time (ID No IC7)
of 250 ns must then be met. This is automatically 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 IC9) + data_setup_time(ID No IC7) = 1000 + 250 = 1250 ns (according to the Standard-mode I2C-bus
specification) before the I2CLK line is released.
4 C
b = total capacitance of one bus line in pF.
Table 70. I2C Module Timing Parameters: 1.8 V +/– 0.10 V
ID
Parameter
Standard Mode
Unit
Min.
Max.
IC1
I2CLK cycle time
10
-
μs
IC2
Hold time (repeated) START condition
4.0
-
μs
IC3
Set-up time for STOP condition
4.0
-
μs
IC4
Data hold time
01
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.
3.452
2 The maximum hold time has only to be met if the device does not stretch the LOW period (ID no IC5) of the I2CLK signal
μs
IC5
HIGH Period of I2CLK Clock
4.0
-
μs
IC6
LOW Period of the I2CLK Clock
4.7
-
μs
IC7
Set-up time for a repeated START condition
4.7
-
μs
IC8
Data set-up time
250
-
ns
IC9
Bus free time between a STOP and START condition
4.7
-
μs
IC10
Rise time of both I2DAT and I2CLK signals
-
1000
ns
IC11
Fall time of both I2DAT and I2CLK signals
-
300
ns
IC12
Capacitive load for each bus line (Cb)-
400
pF