CHAPTER 15 SERIAL INTERFACE IICA
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Figure 15 - 9 Format of IICA control register n0 (IICCTLn0) (4/4)
Note
When the SPTn register is read, 0 is always read.
Caution
When bit 3 (TRCn) of the IICA status register n (IICSn) is set to 1 (transmission status), bit 5 (WRELn)
of IICA control register n0 (IICCTLn0) is set to 1 during the ninth clock and wait is canceled, after
which the TRCn bit is cleared (reception status) and the SDAAn line is set to high impedance.
Release the wait performed while the TRCn bit is 1 (transmission status) by writing to the IICA shift
register n.
Remark
n = 0, 1
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 ACKEn 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 (STTn).
• The SPTn bit can be set to 1 only when in master mode.
• When the WTIMn bit has been cleared to 0, if the SPTn 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 WTIMn bit
should be changed from 0 to 1 during the wait period following the output of eight clocks, and the SPTn bit should be
set to 1 during the wait period that follows the output of the ninth clock.
• Once SPTn is set (1), setting it again (1) before the clear condition is met is not allowed.
Condition for clearing (SPTn = 0)
Condition for setting (SPTn = 1)
• Cleared by loss in arbitration
• Automatically cleared after stop condition is detected
• Cleared by LRELn = 1 (exit from communications)
• When IICEn = 0 (operation stop)
• Reset
• Set by instruction
Содержание RL78/G1H
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