Data Packet And Packet Handler; Direct Mode - CMOSTEK CMT2310A Manual

6 Data Packet and Packet Handler

Data mode specifies how the MCU inputs transmission data and acquires received data. The CMT2310A supports both direct
mode and packet mode.
Direct Mode - In Rx mode, it only supports preamble and sync detection, namely FIFO does not work; demodulated data is
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sent out from GPIO. In Tx mode, it only supports transmitting the data input from GPIO.
Packet Mode – it supports all packet formats and FIFO.
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6.1 Direct Mode

Rx processing
In direct mode, the data from the demodulator is sent directly to the external MCU via the DOUT pin. DOUT can be set as GPIO
1- GPIO 5 and NIRQ.The typical RX direct mode control sequence for the MCU is shown as follow:
1. Configure GPIO through register CUS_IO_SEL.
2. Configure DATA_MODE = 0.
3. Send the go_rx command.
4. Capture the data from DOUT continuously.
5. Send the go_sleep/go_stby/go_rfs command to complete receiving and meanwhile to save power.
Tx processing
In direct mode, the data to be transmitted is sent directly to the chip from the external MCU through DIN pin (4 FSK transmission
does not support this mode). The data rate is determined by the MCU but should be close to the data rate value configured on
RFPDK (with the difference not more than +/- 30%). The typical TX direct mode control sequence for the MCU is shown as follow:
1. Set register TX_DIN_EN to 1 to enable DIN of GPIO.
2. Select which GPIO is used to input data from through configuring register TX_DIN_SEL.
3. Send the go_tx command and meanwhile send the data into DIN pin. The data will be transmitted immediately
following the specified data rate.
4. Send the go_sleep/go_stby/go_rfs command to complete transmission and and meanwhile to save power.
Figure 26. Direct Mode Data Path
Rev 1.0E | Page33/50
CMT2310A
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