Polarity Select Function - Renesas M16C Series Hardware Manual

R8C/11 Group

13.1.1 Polarity Select Function

Figure 13.7 shows the polarity of the transfer clock. Use the CKPOL bit in the U0C0 register to select
the transfer clock polarity.
( 1 ) W h e n t h e U 0 C 0 r e g i s t e r C K P O L b i t = 0 ( t r a n s m i t d a t a o u t p u t a t t h e f a l l i n g
e d g e a n d t h e r e c e i v e d a t a t a k e n i n a t t h e r i s i n g e d g e o f t h e t r a n s f e r c l o c k )
C L K
(1 )
0
T D
X 0
R D
X 0
( 2 ) W h e n t h e U 0 C 0 r e g i s t e r C K P O L b i t = 1 ( t r a n s m i t d a t a o u t p u t a t t h e r i s i n g
e d g e a n d t h e r e c e i v e d a t a t a k e n i n a t t h e f a l l i n g e d g e o f t h e t r a n s f e r c l o c k )
C L K (2 )
0
T D
X 0
R D
X 0
NOTES:
1. When not transferring, the CLK0 pin outputs a high signal.
2. When not transferring, the CLK0 pin outputs a low signal.
Figure 13.7 Transfer Clock Polarity
13.1.2 LSB First/MSB First Select Function
Figure 13.8 shows the transfer format. Use the UFORM bit in the U0C0 register to select the transfer
format.
( 1 ) W h e n U 0 C 0 r e g i s t e r U F O R M b i t = 0 ( L S B f i r s t )
C L K
0
T D
X 0
R D
X 0
( 2 ) W h e n U 0 C 0 r e g i s t e r U F O R M b i t = 1 ( M S B f i r s t )
C L K
0
T D
X 0
R D
X 0
N O T E S :
1 . T h i s a p p l i e s t o t h e c a s e w h e r e t h e C K P O L b i t i n t h e U 0 C 0 r e g i s t e r i s
s e t t o " 0 " ( t r a n s m i t d a t a o u t p u t a t t h e f a l l i n g e d g e a n d t h e r e c e i v e
d a t a t a k e n i n a t t h e r i s i n g e d g e o f t h e t r a n s f e r c l o c k ) .
Figure 13.8 Transfer Format
Rev.1.20 Jan 27, 2006
REJ09B0062-0120
D 0 D D
1 2
D D D
0 1 2
D D D
0 1 2
D D D
0 1 2
D0 D D
1 2
D D D
1 2
0
D D D
7 6 5
D D
D 6 5
7
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13.1 Clock Synchronous Serial I/O Mode
D D D D D
3 4 5 6
D D D D D
3 4 5 6
D D D D D
3 4 5 6
D D D D D
3 4 5 6
D D D D
3 4 5 6
D D D D
3 4 5 6
D D D D
4 3 2 1
D D D D
4 3 2 1
7
7
7
7
D
7
D
7
D
0
D
0