BAT32G1x9 user manual | Chapter 20 Serial interface IICA
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Rev.1.02
Figure 20-6
Format of IICA control register n0 (IICCTLn0) (3/4).
STTn
note1, 2
The triggering of the start condition
0
No start conditions are generated.
1
When the bus is released (standby, IICBSYn bit is "0"): If this
position is "1", a start condition (boot as the master device) is
generated. When a third party is communicating:
• Allow communication in the case of the reservation function (IICRSVn=0,1).
Used as a start condition reservation sign. If you place this position "1", a start condition is
automatically generated just after the bus is released.
• The case where the communication reservation function is prohibited (IICRSVn=1).
Even if this position is "1", the STTn bit is cleared and the STTn clear flag (STCFn) is set to
"1" without generating a start condition. Wait status (master device):
Generates a restart condition after the wait is lifted.
Notes on position timing:
• Master Receive: Disables this position "1" during transmission. This position "1" can only be placed during the
waiting period when ACKEn is at position "0" and notifying the slave that receiving it has completed.
•Master Send: During the Ack, the start condition may not be generated properly. This position "1" must be placed
during the wait period after the 9th clock is output.
•Prohibit and Trigger of Stop Condition (SPTn) with "1" at the same time.
•After placing stTn at the position "1", it is forbidden to use this bit "1" again until the purge condition is met.
Clear condition (STTn=0,1).
Position condition (STTn=1).
• Place stTn at the position "1" in a state where
communication reservation is prohibited.
• When arbitration fails
•Master device generation start condition.
• Cleared because the LRELn bit is "1" (Exit
Communication).
• When the IICEn bit is "0" (stop running).
• When resetting
• Set by command.
Note 1
In the
state where the
IICEn
bit is
"0", the signal for this bit is invalid.
2. The read value of the STTn bit is always
"0".
Remarks: 1
If
bit1
(STTn
)
is read after setting the data, this bit becomes
"0".
IICRSVn
:
Bit0 of IICA
flag register
n
(IICFn
).
STCFn
:
Bit7
of
IICA
flag register
n
(IICFn
).
3. n=0.1