Renesas rl78 Answering Machine User Manual


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RL78/G1A CHAPTER 13 SERIAL INTERFACE IICA
Figure 13-6. Format of IICA Control Register 00 (IICCTL00) (4/4)
SPT0
Note
Stop condition trigger
0 Stop condition is not generated.
1 Stop condition is generated (termination of master device’s transfer).
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 the ACKE0 bit 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 start condition trigger (STT0).
The SPT0 bit can be set to 1 only when in master mode.
When the WTIM0 bit has been cleared to 0, if the SPT0 bit 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. The WTIM0
bit should be changed from 0 to 1 during the wait period following the output of eight clocks, and the SPT0 bit should
be set to 1 during the wait period that follows the output of the ninth clock.
Once STT0 is set (1), setting it again (1) before the clear condition is met is not allowed.
Condition for clearing (SPT0 = 0) Condition for setting (SPT0 = 1)
Cleared by loss in arbitration
Set by instruction
Automatically cleared after stop condition is detected
Cleared by LREL0 = 1 (exit from communications)
When IICE0 = 0 (operation stop)
Reset
Note The SPT0 bit is always read as 0.
<R>
Caution When bit 3 (TRC0) of the IICA status register 0 (IICS0) is set to 1 (transmission status), bit 5
(WREL0) of IICA control register 00 (IICCTL00) is set to 1 during the ninth clock and wait is
canceled, after which the TRC0 bit is cleared (reception status) and the SDAA0 line is set to
high impedance. Release the wait performed while the TRC0 bit is 1 (transmission status)
by writing to the IICA shift register 0.
Remark Bit 0 (SPT0) becomes 0 when it is read after data setting.
R01UH0305EJ0200 Rev.2.00 577
Jul 04, 2013