User's Manual

Signal Interface

The CC1020 can be used with NRZ (Non-Return-to-Zero) data or Manchester (also known as

bi-phase-level) encoded data.CC1020 can also synchronize the data from the demodulator and provide the

data clock at DCLK. The data format is controlled by the DATA_FORMAT[1:0] bits in the MODEM

CC1020 can be configured for three different data formats:

Synchronous NRZ mode. In transmit mode CC1020 provides the data clock at DCLK, and DIO is used as

data input. Data is clocked into CC1020 at the rising edge of DCLK. The data is modulated at RF without

encoding. In receive mode CC1020 does the synchronization and provides received data clock at DCLK

and data at DIO. The data should be clocked into the interfacing circuit at the rising edge of DCLK. See

Figure 8.

Synchronous Manchester encoded mode. In transmit mode CC1020 provides the data clock at DCLK, and

DIO is used as data input. Data is clocked into CC1020 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 CC1020. In this mode

the effective bit rate is half the baud rate due to the coding. In receive mode CC1020 does the

synchronization and provides received data clock at DCLK and data at DIO. CC1020 does 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 9.

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.

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.

Transparent Asynchronous UART mode. In transmit mode DIO is used as data input. The data is modulated

at RF without synchronization or encoding. In receive mode the raw data signal from the demodulator is

sent to the output (DIO). No synchronization or decoding of the signal is done in CC1020 and should be

done by the interfacing circuit.

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