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CHAPTER 16 SERIAL INTERFACE IICA
User’s Manual U19780EJ2V0UD
433
Figure 16-5. Format of IICA Control Register 0 (IICACTL0) (4/4)
SPT0
Stop condition trigger
0
Stop condition is not generated.
1
Stop condition is generated (termination of master device’s transfer).
After the SDAA0 line goes to low level, either set the SCLA0 line to high level or wait until it goes to high
level. Next, after the rated amount of time has elapsed, the SDAA0 line changes from low level to high
level and a stop condition is generated.
Cautions concerning set timing
•
For master reception:
Cannot be set to 1 during transfer.
Can be set to 1 only in the waiting period when ACKE0 has been cleared to 0 and slave
has been notified of final reception.
•
For master transmission: A stop condition cannot be generated normally during the acknowledge period.
Therefore, set it during the wait period that follows output of the ninth clock.
•
Cannot be set to 1 at the same time as STT0.
•
SPT0 can be set to 1 only when in master mode
Note
.
•
When WTIM0 has been cleared to 0, if SPT0 is set to 1 during the wait period that follows output of eight clocks,
note that a stop condition will be generated during the high-level period of the ninth clock. WTIM0 should be
changed from 0 to 1 during the wait period following the output of eight clocks, and SPT0 should be set to 1 during
the wait period that follows the output of the ninth clock.
•
Setting SPT0 to 1 and then setting it again before it is cleared to 0 is prohibited.
Condition for clearing (SPT0 = 0)
Condition for setting (SPT0 = 1)
•
Cleared by loss in arbitration
•
Automatically cleared after stop condition is detected
•
Cleared by LREL0 = 1 (exit from communications)
•
When IICE0 = 0 (operation stop)
•
Reset
•
Set by instruction
Note
Set SPT0 to 1 only in master mode. However, SPT0 must be set to 1 and a stop condition
generated before the first stop condition is detected following the switch to the operation enabled
status.
Caution
When the bit 3 (TRC0) of the IIC status register 0 (IICAS0) is set to 1, WREL0 is set to 1
during the ninth clock and wait is canceled, after which TRC0 is cleared and the SDAA0
line is set to high impedance.
Remark
Bit 0 (SPT0) becomes 0 when it is read after data setting.