MC908AP16CFAE Datasheet, PDF (310/324 Pages) Freescale Semiconductor, Inc – Table of Contents

Electrical Specifications
Table 22-13. MMIIC Interface Input/Output Signal Timing
Characteristic
Symbol Min Typ Max Unit
Comments
Operating frequency
f_SMB
10
—
100 kHz MMIIC operating frequency
Bus free time
t_BUF
4.7
—
—
µs
Bus free time between STOP and
START condition
Repeated start hold time.
t_HD.STA
4.0
—
Hold time after (repeated) START
—
µs condition. After this period, the first
clock is generated.
Repeated start setup time.
t_SU.STA
4.7
—
—
µs Repeated START condition setup time.
Stop setup time
t_SU.STO
4.0
—
—
µs Stop condition setup time.
Hold time
t_HD.DAT
300
—
—
ns Data hold time.
Setup time
t_SU.DAT
250
—
—
ns Data setup time.
Clock low time-out
t_TIMEOUT
25
—
35
ms _{Clock low time-out.}⁽¹⁾
Clock low
t_LOW
4.7
—
—
µs Clock low period
Clock high
t_HIGH
4.0
—
—
µs _{Clock high period.}⁽²⁾
Slave clock low extend time
t_LOW.SEXT
—
—
Cumulative clock low extend time (slave
25
ms _device)(3)
Master clock low extend time
t_LOW.MEXT
—
—
Cumulative clock low extend time
10
ms _{(master device) (4)}
Fall time
t_F
—
—
300
ns _{Clock/Data Fall Time}⁽⁵⁾
Rise time
t_R
—
—
1000
ns _{Clock/Data Rise Time}⁽⁵⁾
1. Devices participating in a transfer will timeout when any clock low exceeds the value of T_TIMEOUT min. of 25ms. Devices
that have detected a timeout condition must reset the communication no later than T_TIMEOUT max of 35ms. The maximum
value specified must be adhered to by both a master and a slave as it incorporates the cumulative limit for both a master
(10 ms) and a slave (25 ms).
Software should turn-off the MMIIC module to release the SDA and SCL lines.
2. T_{HIGH MAX} provides a simple guaranteed method for devices to detect the idle conditions.
3. T_LOW.SEXT is the cumulative time a slave device is allowed to extend the clock cycles in one message from the initial start
to the stop. If a slave device exceeds this time, it is expected to release both its clock and data lines and reset itself.
4. T_LOW.MEXT is the cumulative time a master device is allowed to extend its clock cycles within each byte of a message as
defined from start-to-ack, ack-to-ack, or ack-to-stop.
5. Rise and fall time is defined as follows: T_R = (V_ILMAX – 0.15) to (V_IHMIN + 0.15), T_F = 0.9×V_DD to (V_ILMAX – 0.15).
MC68HC908AP Family Data Sheet, Rev. 4
308
Freescale Semiconductor