HT82M75REW/HT82K75REW
Rev. 1.00
37
June 11, 2010
SPI Configuration Options and Status Control
One option is to enable the operation of the WCOL, write collision bit, in the SBCR register. Some control in SPIR register.
The SPI_CPOL select the clock polarity of the SCK line . The SPI_MODE select SPI data output mode.
SPI include four pins , can share I/O mode status . The status control combine with four bits for SPIR and SBCR regis-
ter. Include SPI_CSEN , SPI_EN for SPIR register and CSEN ,SBEN for SBCR register.
SPIR(22H)
SBCR(23H)
I/O Status
Note
SPI_EN
SPI_CSEN
SBEN
CSEN
SPI
SCS
0
x
x
x
I/O mode
I/O mode
1
x
0
x
I/O mode
I/O mode
1
0
1
x
SPI mode
I/O mode
SCS not Floating
1
1
1
0
SPI mode
I/O mode
SCS not Floating
1
1
1
1
SPI mode
SCS mode
The SPI enable, SCS, SDI,
SDO, SCK the internal
Pull-high function is invalid.
Note:
X: don
¢
t care
Error Detection
The WCOL bit in the SBCR register is provided to indi-
cate errors during data transfer. The bit is set by the Se-
rial Interface but must be cleared by the application
program. This bit indicates a data collision has occurred
which happens if a write to the SBDR register takes
place during a data transfer operation and will prevent
the write operation from continuing. The bit will be set
high by the Serial Interface but has to be cleared by the
user application program. The overall function of the
WCOL bit can be disabled or enabled by a configuration
option.
Programming Considerations
When the device is placed into the Power Down Mode
note that data reception and transmission will continue.
The TRF bit is used to generate an interrupt when the
data has been transferred or received.
S B C R R e g i s t e r
b 7
b 0
C K S
M 1
M 0
S B E N M L S C S E N W C O L T R F
T r a n s m i t t / R e c e i v e f l a g
0 : N o t c o m p l e t e
1 : T r a n s m i s s i o n / r e c e p t i o n c o m p l e t e
W r i t e c o l l i s i o n b i t
0 : C o l l i s i o n f r e e
1 : C o l l i s i o n d e t e c t e d
S e l e c t i o n s i g n a l e n a b l e / d i s a b l e b i t
0 : S C S f l o a t i n g f o r I / O m o d e
1 : E n a b l e
M S B / L S B f i r s t b i t
0 : L S B s h i f t f i r s t
1 : M S B s h i f t f i r s t
S e r i a l B u s e n a b l e / d i s a b l e b i t
0 : D i s a b l e
1 : E n a b l e
M a s t e r / S l a v e / B a u d r a t e b i t s
M a s t e r , b a u d r a t e : f
S P I
M a s t e r , b a u d r a t e : f
S P I
/ 4
M a s t e r , b a u d r a t e : f
S P I
/ 1 6
S l a v e m o d e
M 1
0
0
1
1
M 0
0
1
0
1
C l o c k s o u r c e s e l e c t b i t
0 : f
S P I
= f
S Y S
/ 2
1 : f
S P I
= f
S Y S
SPI Interface Control Register
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