5.6.3 Synchronous Manchester Encoded Mode

In transmit mode, the CC1021 device provides the data clock at DCLK and DIO is used as data input. Data is clocked into the CC1021 device at the rising edge of DCLK and should be in NRZ format. The data is modulated at RF with Manchester code. The encoding is done by the CC1021 device. In this mode, the effective bit rate is half the baud rate due to the coding. As an example, 19.2 kBaud Manchester encoded data corresponds to 9.6 kbps.

In receive mode, the CC102 device performs the synchronization and provides received data clock at DCLK and data at DIO. The CC1021 device performs the decoding and NRZ data is presented at DIO. The data should be clocked into the interfacing circuit at the rising edge of DCLK. See Figure 5-7.

In synchronous NRZ or Manchester mode the DCLK signal runs continuously both in RX and TX unless the DCLK signal is gated with the carrier sense signal or the PLL lock signal. Refer to Section 5.18 for more details.

If SEP_DI_DO = 0 in the INTERFACE register, the DIO pin is the data output in receive mode and data input in transmit mode.

As an option, the data output can be made available at a separate pin. This is done by setting SEP_DI_DO = 1 in the INTERFACE register. Then, the LOCK pin will be used as data output in synchronous mode, overriding other use of the LOCK pin.