BS84B08A-3 Datasheet, PDF (80/123 Pages) Holtek Semiconductor Inc – A/D Type Touch Key MCU

BS84B08A-3/BS84C12A-3
A/D Type Touch Key MCU
D a ta B u s
S IM D
T x /R x S h ift R e g is te r
S D I P in
S D O P in
C K E G b it
C K P O L B b it
S C K P in
fS Y S
f_{5 7 *}
T im e r o v e r flo w fr e q u e n c y /2
C lo c k
E d g e /P o la r ity
C o n tro l
C lo c k
S o u r c e S e le c t
B usy
S ta tu s
W C O L F la g
T R F F la g
S C S P in
C S E N b it
SPI Block Diagram
The SPI function in this device offers the following features:
• Full duplex synchronous data transfer
• Both Master and Slave modes
• LSB first or MSB first data transmission modes
• Transmission complete flag
• Rising or falling active clock edge
The status of the SPI interface pins is determined by a number of factors such as whether the device
is in the master or slave mode and upon the condition of certain control bits such as CSEN and
SIMEN.
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 I²C interface.
Register
Bit
Name
7
6
5
4
3
2
1
0
SIMC0 SIM2
SIM1
SIM0
—
—
—
SIMEN
—
SIMD
D7
D6
D5
D4
D3
D2
D1
D0
SIMC2
—
—
CKPOLB CKEG
MLS
CSEN WCOL
TRF
SIM 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 I²C 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
device can read it from the SIMD register. Any transmission or reception of data from the SPI bus
must be made via the SIMD register.
Rev. 1.00
80
May 02, 2013