Table of Contents
Advertisement
2
I
C Bus (IIC)
17.14 Cautions
(1)
(2)
(3)
(4)
(5)
(6)
When IICFn.STCENn bit = 0
Immediately after the I
(IICFn.IICBSYn bit = 1) is recognized regardless of the actual bus status. To
execute master communication in the status where a stop condition has not
been detected, generate a stop condition and then release the bus before
starting the master communication.
Use the following sequence for generating a stop condition.
<1> Set the IICCLn register.
<2> Set the IICCn.IICEn bit.
<3> Set the IICCn.SPTn bit.
When IICFn.STCENn bit = 1
2
Immediately after I
Cn operation is enabled, the bus released status (IICBSYn
bit = 0) is recognized regardless of the actual bus status. To issue the first start
condition (IICCn.STTn bit = 1), it is necessary to confirm that the bus has been
released, so as to not disturb other communications.
When the IICC0.IICE0 bit of the microcontroller is set to 1 while
communications with other devices are in progress, the start condition may be
detected depending on the status of the communication line. Be sure to set
the IICC0.IICE0 bit to 1 when the SCL00 and SDA00 lines are high level.
Determine the operation clock frequency by the IICCL0, IICX0, and OCKS0
registers before enabling the operation (IICC0.IICE0 bit = 1). To change the
operation clock frequency, clear the IICC0.IICE0 bit to 0 once.
After the IICC0.STT0 and IICC0.SPT0 bits have been set to 1, they must not
be re-set without being cleared to 0 first.
If transmission has been reserved, set the IICCN.SPIE0 bit to 1 so that an
interrupt request is generated by the detection of a stop condition. After an
interrupt request has been generated, the wait state will be released by writing
communication data to I2C0, then transferring will begin. If an interrupt is not
generated by the detection of a stop condition, transmission will halt in the wait
state because an interrupt request was not generated.
However, it is not necessary to set the SPIE0 bit to 1 for the software to detect
the IICS0.MSTS0 bit."
User's Manual U18743EE1V2UM00
2
Cn operation is enabled, the bus communication status
Chapter 17
511
Advertisement
Table of Contents
