BS85B12-3 HOLTEK [Holtek Semiconductor Inc], BS85B12-3 Datasheet - Page 121

• Manufacturer Part Number: BS85B12-3
• Description: Touch Key Flash Type 8-Bit MCU with LCD/LED Driver
• Manufacturer: HOLTEK [Holtek Semiconductor Inc]

BS85B12-3/BS85C20-3
Touch Key Flash MCU with LCD/LED Driver
Rev. 1.00
SPI Communication
After the SPI interface is enabled by setting the SIMEN bit high, then in the Master Mode, when data is
written to the SIMD register, transmission/reception will begin simultaneously. When the data transfer
is complete, the TRF flag will be set automatically, but must be cleared using the application program.
In the Slave Mode, when the clock signal from the master has been received, any data in the SIMD
register will be transmitted and any data on the SDI pin will be shifted into the SIMD register. The
master should output an SCS signal to enable the slave device before a clock signal is provided. The
slave data to be transferred should be well prepared at the appropriate moment relative to the SCS
signal depending upon the configurations of the CKPOLB bit and CKEG bit. The accompanying
timing diagram shows the relationship between the slave data and SCS signal for various
configurations of the CKPOLB and CKEG bits.
The SPI will continue to function even in the IDLE Mode.
SPI Slave Mode Timing - CKEG=0
SPI Master Mode Timing
115
February 1, 2011