Renesas H8S/2111B 用户手册

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页码 582
Rev. 1.00, 05/04, page 301 of 544 
 
13.3.7 
DDC Switch Register (DDCSWR) 
DDCSWR controls IIC internal latch clearance. 
Bit Bit 
Name 
Initial 
Value R/W  Description 
7 to 5 
— 
All 0 
R/W 
Reserved 
The initial value should not be changed.  
4 — 
0  R  Reserved 
CLR3 
CLR2 
CLR1 
CLR0 
W* 
W* 
W* 
W* 
IIC Clear 3 to 0 
Controls initialization of the internal state of IIC_0 and 
IIC_1. 
00--: Setting prohibited 
0100: Setting prohibited 
0101: IIC_0 internal latch cleared 
0110: IIC_1 internal latch cleared 
0111: IIC_0 and IIC_1 internal latches cleared 
1---: Invalid setting 
When a write operation is performed on these bits, a 
clear signal is generated for the internal latch circuit of 
the corresponding module, and the internal state of the 
IIC module is initialized. 
These bits can only be written to; they are always read 
as 1. Write data to this bit is not retained. 
To perform IIC clearance, bits CLR3 to CLR0 must be 
written to simultaneously using an MOV instruction. Do 
not use a bit manipulation instruction such as BCLR. 
When clearing is required again, all the bits must be 
written to in accordance with the setting. 
Note:  *  This bit is always read as 1.