588
Chapter 18
I
2
C Bus (IIC)
Preliminary User’s Manual U17566EE1V2UM00
(4)
IICCLn - IICn clock select registers
The IICCLn registers set the transfer clock for the I
2
Cn bus.
The SMCn, CLn1, and CLn0 bits are set by the combination of the IICXn.CLXn
bit and the OCKSTHn, OCKSn[1:0] bits of the OCKSn register (see
“Transfer
rate setting“ on page 590
).
Access
This register can be read/written in 8-bit or 1-bit units.
CLDn and DADn bits are read-only.
Address
<base> + 4
H
Initial Value
00
H
. This register is cleared by any reset.
7
6
5
4
3
2
1
0
0
0
CLDn
DADn
SMCn
DFCn
CLn1
CLn0
R/W
R/W
R
R
R/W
R/W
R/W
R/W
CLDn
Detection of SCLn pin level (valid only when IICCn.IICEn = 1)
0
The SCLn pin was detected at low level.
1
The SCLn pin was detected at high level.
Condition for clearing (CLDn = 0)
Condition for setting (CLDn = 1)
•
When the SCLn pin is at low level
•
When the IICEn = 0 (operation stop)
•
After reset
•
When the SCLn pin is at high level
DADn
Detection of SDAn pin level (valid only when IICEn = 1)
0
The SDAn pin was detected at low level.
1
The SDAn pin was detected at high level.
Condition for clearing (DADn = 0)
Condition for setting (DAD0n = 1)
•
When the SDAn pin is at low level
•
When the IICEn = 0 (operation stop)
•
After reset
•
When the SDAn pin is at high level
SMCn
Operation mode switching
0
Operation in standard mode.
1
Operation in fast-speed mode.
DFCn
Digital filter operation control
0
Digital filter off.
1
Digital filter on.
The digital filter can be used only in fast-speed mode.
In fast-speed mode, the transfer clock does not vary regardless of the DFCn bit setting (on/off).
The digital filter is used to eliminate noise in fast-speed mode.
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