CHAPTER 10 SERIAL INTERFACE FUNCTION
User’s Manual U13850EJ6V0UD
428
The bit length of a variable-length register is set by setting bits 3 to 0 (BSEL3 to BSEL0) of CSIB4. Data is
transferred MSB first while bit 4 (DIR) is 1, and is transferred LSB first while DIR is 0.
Figure 10-59. CSIB4 Setting (3-Wire Variable-Length Serial I/O Mode)
After reset:
00H
R/W
Address: FFFFF2E4H
7
<6>
<5>
<4>
3
2
1
0
CSIB4
0
CMODE
DMODE
DIR
BSEL3
BSEL2
BSEL1
BSEL0
CMODE
DMODE
SCK4 active level
SI4 interrupt timing
SO4 output timing
0
0
Low level
Rising edge of SCK4
Falling edge of SCK4
0
1
Low level
Falling edge of SCK4
Rising edge of SCK4
1
0
High level
Falling edge of SCK4
Rising edge of SCK4
1
1
High level
Rising edge of SCK4
Falling edge of SCK4
DIR
Serial transfer direction
0
LSB first
1
MSB first
BSEL3
BSEL2
BSEL1
BSEL0
Bit length of serial register
0
0
0
0
16 bits
1
0
0
0
8 bits
1
0
0
1
9 bits
1
0
1
0
10 bits
1
0
1
1
11 bits
1
1
0
0
12 bits
1
1
0
1
13 bits
1
1
1
0
14 bits
1
1
1
1
15 bits
Other than above
Setting prohibited
Содержание V850/SB1
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