CC2420 Chipcon AS, CC2420 Datasheet - Page 67

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

FSCTRL (0x18) - Frequency Synthesizer Control and Status
15:14
13
12
11
10
9:0
Chipcon AS SmartRF ® CC2420 Preliminary Datasheet (rev 1.0), 2003-11-17
Bit
Field Name
LOCK_THR[1:0]
CAL_DONE
CAL_RUNNING
LOCK_LENGTH
LOCK_STATUS
FREQ[9:0]
Reset
1
0
0
0
0
357
(2405
MHz)
R/W
R/W
R
R
R/W
R
R/W
SmartRF
Description
Number of consecutive reference clock periods with successful
synchronisation windows required to indicate lock:
0: 64
1: 128 (recommended)
2: 256
3: 512
Calibration has been performed since the last time the frequency
synthesizer was turned on.
Calibration status, '1' when calibration in progress and ‘0’
otherwise.
Synchronisation window pulse width:
0: 2 prescaler clock periods (recommended)
1: 4 prescaler clock periods
Frequency synthesizer lock status:
0 : Frequency synthesizer is out of lock
1 : Frequency synthesizer is in lock
Frequency control word, controlling the RF operating frequency
F
F
F
See the Frequency and Channel Programming section on page
47 for further information.
C
C
C
. In transmit mode, the local oscillator (LO) frequency equals
. In receive mode, the LO frequency is 2 MHz below F
= 2048 + FREQ[9:0] MHz
®
CC2420
Page 67 of 85
C
.