Rev. 1.10
146
October 23, 2020
Rev. 1.10
147
October 23, 2020
BC66F5652
2.4GHz RF Transceiver A/D Flash MCU
BC66F5652
2.4GHz RF Transceiver A/D Flash MCU
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 a SCS signal to enable the slave devices before a clock signal
is provided. The slave data to be transferred should be well prepared at the appropriate moment
relative to the SCK signal depending upon the configurations of the CKPOLB bit and CKEG bit.
The accompanying timing diagram shows the relationship between the slave data and SCK signal
for various configurations of the CKPOLB and CKEG bits.
The SPI will continue to function in certain IDLE Modes if the clock source used by the SPI
interface is still active.
SCK (CKPOLB=1, CKEG=0)
SCK (CKPOLB=0, CKEG=0)
SCK (CKPOLB=1, CKEG=1)
SCK (CKPOLB=0, CKEG=1)
SCS
SDO (CKEG=0)
SDO (CKEG=1)
SDI Data Capture
Write to SIMD
SIMEN, CSEN=1
SIMEN=1, CSEN=0 (External Pull-high)
D7/D0 D6/D1 D5/D2 D4/D3 D3/D4 D2/D5 D1/D6 D0/D7
D7/D0 D6/D1 D5/D2 D4/D3 D3/D4 D2/D5 D1/D6 D0/D7
SPI Master Mode Timing
SCK (CKPOLB=1)
SCK (CKPOLB=0)
SCS
SDO
SDI Data Capture
Write to SIMD
(SDO does not change until first SCK edge)
D7/D0 D6/D1 D5/D2 D4/D3 D3/D4 D2/D5 D1/D6 D0/D7
SPI Slave Mode Timing – CKEG=0