CC2420 Chipcon AS, CC2420 Datasheet - Page 53

• Manufacturer Part Number: CC2420
• Description: 2.4 GHz RF Transceiver for IEEE 802.15.4 and ZigBee
• Manufacturer: Chipcon AS

Date:
Modulated spectrum
The
generator that can generate pseudo
random
generator. This is enabled by setting
MDMCTRL1.TX_MODE to 3 and issue a
STXON command strobe. The modulated
spectrum is then available on the RF pins.
The low byte of the CRC word is
transmitted and the CRC is updated with
0xFF for each new byte. The length of the
transmitted data sequence is 65535 bits.
The transmitted data-sequence is then:
[synchronisation
0xb8, 0x4b, 0x99, 0xc3, 0xe9, …]
Since a synchronisation header (preamble
and SFD) is transmitted in all TX modes,
this test mode may also be used to
transmit
Chipcon AS SmartRF ® CC2420 Preliminary Datasheet (rev 1.0), 2003-11-17
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3
0
Ref Lvl
Ref Lvl
Center 2.45 GHz
CC2420
1AVG
3 dBm
3 dBm
a
sequence
23.OCT.2003
known
has a built-in test pattern
header]
pseudorandom
using
21:38:33
[0x00, 0x78,
Figure 29. Single carrier output
the
CRC
bit
200 kHz/
SmartRF
RBW
VBW
SWT
sequence for bit error testing. Please note
that
synchronisation,
synchronisation, for correct reception.
Packet error rate is therefore a better
measurement
performance.
Another option to generate a modulated
spectrum is to fill the TXFIFO with pseudo-
random
MDMCTRL1.TX_MODE to 3.
then
disregarding a TXFIFO underflow. The
length of the transmitted data sequence is
then 1024 bits (128 bytes).
A plot of the modulated spectrum from
CC2420
find the output power from the modulated
spectrum, the RBW must be set to 3 MHz
or higher.
transmit
10 kHz
10 kHz
50 ms
is shown in Figure 30. Note that to
CC2420
data
data
for
®
RF Att
Unit
requires
not
CC2420
the
from
Span 2 MHz
and
30 dB
only
CC2420
Page 53 of 85
true
the
dBm
symbol
FIFO
1SA
A
will
RF
set
bit