SPI Registers
There are three internal registers which control the overall operation of the SPI interface. These are the
SIMD data register and two registers SIMC0 and SIMC2. Note that the SIMC1 register is only used by
the I
2
C interface.
Register
Name
Bit
7
6
5
4
3
2
1
0
SIMC0
SIM2
SIM1
SIM0
¾
¾
¾
SIMEN
¾
SIMD
D7
D6
D5
D4
D3
D2
D1
D0
SIMC2
D7
D6
CKPOLB
CKEG
MLS
CSEN
WCOL
TRF
SPI Registers List
The SIMD register is used to store the data being transmitted and received. The same register is used
by both the SPI and I
2
C functions. Before the device writes data to the SPI bus, the actual data to be
transmitted must be placed in the SIMD register. After the data is received from the SPI bus, the de-
vice can read it from the SIMD register. Any transmission or reception of data from the SPI bus must
be made via the SIMD register.
SIMD Register
Bit
7
6
5
4
3
2
1
0
Name
D7
D6
D5
D4
D3
D2
D1
D0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
x
x
x
x
x
x
x
x
²
x
²
unknown
Rev. 1.50
82
April 28, 2020
BS83B08-3/B12-3/B16-3/B16G-3/C24-3
8-Bit Touch Key Flash MCU
D a t a B u s
S D I P i n
S D O P i n
S I M D
T x / R x S h i f t R e g i s t e r
B u s y
S t a t u s
T R F F l a g
W C O L F l a g
C l o c k
E d g e / P o l a r i t y
C o n t r o l
C l o c k
S o u r c e S e l e c t
f
S Y S
f
L I R C
S C K P i n
C S E N b i t
S C S P i n
C K E N b i t
C K P O L B b i t
SPI Block Diagram