
CHAPTER 17 I
2C BUS
User’s Manual U17790EJ2V0UD
585
After reset: 00H
R/W
Note
Address: IICF0 FFFFFD8AH, IICF1 FFFFFD9AH, IICF2 FFFFFDAAH
<7>
<6>
5
4
3
2
<1>
<0>
IICFn
STCFn
IICBSYn
0
STCENn
IICRSVn
(n = 0 to 2)
STCFn
STTn bit clear
0
Start condition issued
1
Start condition cannot be issued, STTn bit cleared
Condition for clearing (STCFn bit = 0)
Condition for setting (STCFn bit = 1)
Cleared by IICCn.STTn bit = 1
When the IICCn.IICEn bit = 0
After reset
When start condition is not issued and STTn flag is
cleared to 0 during communication reservation is
disabled (IICRSVn bit = 1).
IICBSYn
I
2C0n bus status
0
Bus released status (default communication status when STCENn bit = 1)
1
Bus communication status (default communication status when STCENn bit = 0)
Condition for clearing (IICBSYn bit = 0)
Condition for setting (IICBSYn bit = 1)
When stop condition is detected
When the IICEn bit = 0
After reset
When start condition is detected
By setting the IICEn bit when the STCENn bit = 0
STCENn
Initial start enable trigger
0
Start conditions cannot be generated until a stop condition is detected following operation enable
(IICEn bit = 1).
1
Start conditions can be generated even if a stop condition is not detected following operation enable
(IICEn bit = 1).
Condition for clearing (STCENn bit = 0)
Condition for setting (STCENn bit = 1)
When start condition is detected
After reset
Setting by instruction
IICRSVn
Communication reservation function disable bit
0
Communication reservation enabled
1
Communication reservation disabled
Condition for clearing (IICRSVn bit = 0)
Condition for setting (IICRSVn bit = 1)
Clearing by instruction
After reset
Setting by instruction
Note Bits 6 and 7 are read-only bits.
Cautions 1. Write the STCENn bit only when operation is stopped (IICEn bit = 0).
2. When the STCENn bit = 1, the bus released status (IICBSYn bit = 0) is recognized
regardless of the actual bus status immediately after the I
2Cn bus operation is
enabled. Therefore, to issue the first start condition (STTn bit = 1), it is necessary
to confirm that the bus has been released, so as to not disturb other
communications.
3. Write the IICRSVn bit only when operation is stopped (IICEn bit = 0).