MPC8544E PowerQUICC III Integrated Processor Hardware Specifications, Rev. 6
Freescale Semiconductor
59
I2C
13.2
I2C AC Electrical Specifications
Table 52 provides the AC timing parameters for the I2C interfaces. Table 52. I2C AC Electrical Specifications
All values refer to VIH (min) and VIL (max) levels (see Table 51). Parameter
Symbol1
Min
Max
Unit
Notes
SCL clock frequency
fI2C
0400
kHz
—
Low period of the SCL clock
tI2CL
1.3
—
μs—
High period of the SCL clock
tI2CH
0.6
—
μs—
Setup time for a repeated START condition
tI2SVKH
0.6
—
μs—
Hold time (repeated) START condition (after this period,
the first clock pulse is generated)
tI2SXKL
0.6
—
μs—
Data setup time
tI2DVKH
100
—
ns
—
Data hold time:
CBUS compatible masters
I2C bus devices
tI2DXKL
—
0
—
μs2
Data output delay time
tI2OVKL
—0.9
3
Set-up time for STOP condition
tI2PVKH
0.6
—
μs—
Rise time of both SDA and SCL signals
tI2CR
20 + 0.1 Cb
300
ns
4
Fall time of both SDA and SCL signals
tI2CF
20 + 0.1 Cb
300
ns
4
Bus free time between a STOP and START condition
tI2KHDX
1.3
—
μs—
Noise margin at the LOW level for each connected device
(including hysteresis)
VNL
0.1
× OVDD
—V
—
Noise margin at the HIGH level for each connected
device (including hysteresis)
VNH
0.2
× OVDD
—V
—
Notes:
1. The symbols used for timing specifications follow the pattern of t(first two letters of functional block)(signal)(state)(reference)(state) for
inputs and t(first two letters of functional block)(reference)(state)(signal)(state) for outputs. For example, tI2DVKH symbolizes I
2C timing (I2)
with respect to the time data input signals (D) reach the valid state (V) relative to the tI2C clock reference (K) going to the high
(H) state or setup time. Also, tI2SXKL symbolizes I
2C timing (I2) for the time that the data with respect to the start condition
(S) went invalid (X) relative to the tI2C clock reference (K) going to the low (L) state or hold time. Also, tI2PVKH symbolizes I
2C
timing (I2) for the time that the data with respect to the stop condition (P) reaching the valid state (V) relative to the tI2C clock
reference (K) going to the high (H) state or setup time. For rise and fall times, the latter convention is used with the appropriate
letter: R (rise) or F (fall).
2. The MPC8544E provides a hold time of at least 300 ns for the SDA signal (referred to the VIHmin of the SCL signal) to bridge
the undefined region of the falling edge of SCL.
3. The maximum tI2DXKL has only to be met if the device does not stretch the LOW period (tI2CL) of the SCL signal.
4. CB = capacitance of one bus line in pF.