CC2400 Chipcon AS, CC2400 Datasheet - Page 28

• Manufacturer Part Number: CC2400
• Description: 2.4 GHz RF Transceiver
• Manufacturer: Chipcon AS

Data / Line Encoding
The
line-encoding formats:
The data format is controlled by the
GRMDM.DATA_FORMAT[1:0]
Manchester coding and 8/10 coding
reduce the effective bit rate but are in
some
properties and error detection.
Manchester coding means coding each bit
into two chips of opposite polarity. The
Manchester code is based on transitions;
a “0” is encoded as a low-to-high
transition, a “1” is encoded as a high-to-
low
Manchester code ensures that the signal
has a constant DC component, which is
necessary in some FSK demodulators.
This is not required by the
demodulator, but the coding option is
included for compatibility reasons. The
effective bit rate is half the baud rate using
Manchester coding.
8/10 coding means that 8 bits are coded
into 10 chips using the original IBM
8B/10B-coding scheme. The effective bit
rate is 80 % of the baud rate using 8/10
coding and is therefore more efficient that
the Manchester coding.
The benefit of the Manchester coding and
8/10 coding is the whitening of the
transmission spectrum even when rows of
equal bits are to be transmitted, improved
clock recovery properties and DC balance.
Setting the MDMTST0.INVERT_DATA bit
the data is inverted before transmission in
TX mode and inverted after reception in
RX mode.
Chipcon AS
•
•
•
CC2400
transition.
applications
NRZ (Non-Return-to-Zero)
Manchester coding (also known
as bi-phase-level)
8/10 coding
can operate with the following
SmartRF
See
®
CC2400 PRELIMINARY Datasheet (rev. 1.1), 2003-10-02
used
Figure
for
13.
spectral
CC2400
bits.
The
SmartRF
Data encoding in buffered mode
In the buffered mode, using the internal
FIFO, all three line-encoding schemes can
be used.
The encoding/decoding takes place as the
data is sent from the FIFO to the
modulator, and from the demodulator to
the FIFO. The line encoding is therefore
invisible to the user.
If 8/10 coding is selected when using the
packet mode support, it should be noted
that the preamble and the sync words are
not encoded.
Data encoding in un-buffered mode
When data buffering is not used, but the
DIO/DCLK interface, the
configured for two different data formats:
Synchronous NRZ mode. In transmit
mode
DCLK, and DIO is used as data input.
Data is clocked into
edge of DCLK. The data is modulated at
RF without encoding. In receive mode
CC2400
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 11.
Synchronous Manchester encoded mode.
In transmit mode
clock at DCLK, and DIO is used as data
input. Data is clocked into
rising edge of DCLK and should be in NRZ
format. The data is modulated at RF with
Manchester code. The encoding is done
by
rate is half the baud rate due to the
coding. This limits the maximum bit rate to
500 kbps. In receive mode
the synchronization and provides received
data clock at DCLK and data at DIO.
CC2400
is presented at DIO. The data should be
clocked into the interfacing circuit at the
rising edge of DCLK. See Figure 12.
CC2400
CC2400
does the decoding and NRZ data
does the synchronization and
. In this mode the effective bit
provides the data clock at
CC2400
®
CC2400
CC2400
provides the data
CC2400
CC2400
CC2400
at the rising
Page 28 of 73
can be
at the
does