ht82m73e Holtek Semiconductor Inc., ht82m73e Datasheet - Page 27

• Manufacturer Part Number: ht82m73e
• Description: 2.4ghz Mouse Tx 8-bit Otp Mcu
• Manufacturer: Holtek Semiconductor Inc.

SBCR register is used to setup the required setup pa-
rameters for the SPI bus and also used to store associ-
ated operating flags, while the SBDR register is used for
data storage.
After Power on, the contents of the SBDR register will
be in an unknown condition while the SBCR register will
default to the condition below:
Note that data written to the SBDR register will only be
written to the TXRX buffer, whereas data read from the
SBDR register will actual be read from the register.
SPI Bus Enable/Disable
To enable the SPI bus and CSEN=1, the SCK, SDI,
SDO and SCS lines should all be zero, then wait for data
Rev. 1.00
CKS M1 M0 SBEN MLS CSEN WCOL TRF
0
1
1
0
0
0
SPI Interface Control Register
0
SPI Bus Timing
0
27
to be written to the SBDR (TXRX bufffer) register. For
the Master Mode, after data has been written to the
SBDR (TXRX buffer) register then transmission or re-
ception will start automatically. When all the data has
been transferred the TRF bit should be set. For the
Slave Mode, when clock pulses are received on SCK,
data in the TXRX buffer will be shifted out or data on SDI
will be shifted in.
To Disable the SPI bus SCK, SDI, SDO, SCS floating.
SPI Operation
All communication is carried out using the 4-line inter-
face for both Master or Slave Mode. The timing diagram
shows the basic operation of the bus.
The CSEN bit in the SBCR register controls the overall
function of the SPI interface. Setting this bit high, will en-
able the SPI interface by allowing the SCS line to be ac-
HT82M73E
May 14, 2008