AN201
Rev 1.5 | 11/91
www.cmostek.com
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register address
register write data
r/ w = 0
> 0. 5 SCLK cycle
> 0. 5 SCLK cycle
RFCTRL
PC3/ CSB
PC2/ SCLK
PC1/ SDIO
Figure 5. SPI Write Register Timing
Notes
1.
RFCTRL is an input port requiring external control. It is recommended that users control it through any function port in the
CMT2189B, and pull it down to enable SPI interface function. In the whole process, RFCTRL can keep low, but in the low
power sleep mode, it needs to set the MCU pin controlling RFCTRL to a high impedance input, since the pull-up inside
RFCTRL can pull the level high. Do not set the MCU pin to low output, since pull-down will consume power.
2.5 RF Configuration Parameter
When the CMT2189B operates in the advanced configuration mode, it can achieve a more wide operating frequency range,
packet format, etc. These functions require corresponding configuration parameters, which can be exported by the RFPDK
software. The operating process is: open the RFPDK software and select the CMT2157B model (it has the same specifications
and performance with the built-in RF of the CMT2189B), as shown in the following figure.
RF setting area
Data packet setting area
Figure 6. RFPDK Screen for CMT2157B
