LMX2430 National Semiconductor Corporation, LMX2430 Datasheet - Page 39

• Manufacturer Part Number: LMX2430
• Description: Pllatinum Dual High Frequency Synthesizer For Rf Personal Communications
• Manufacturer: National Semiconductor Corporation

Reg
R0
2.0 Programming Description
2.4 R0 REGISTER
The R0 register contains the RF_R, RF_CPP, RF_CPG, RF_CPT, and RF_RST control words, in addition to two of the four bits
that compose the MUX control word. The detailed descriptions and programming information for each control word is discussed
in the following sections.
2.4.1 RF_R[14:0] - RF Synthesizer Programmable Reference Divider (R Counter) (R0[17:3])
The RF reference divider (RF_R) can be programmed to support divide ratios from 3 to 32767. Divide ratios less than 3 are
prohibited.
2.4.2 RF_CPP - RF Synthesizer Phase Detector Polarity (R0[18])
The RF_CPP bit is used to control the RF synthesizer’s phase/ frequency detector polarity based on the VCO tuning
characteristics.
MUX[3:2]
23
Divide Ratio
32767
22
3
4
•
Control Bit
RF_CPP
RST
RF_
21
CPT
RF_
20
CPG
RF_
19
14
0
0
1
•
CPP
RF_
18
Register Location
13
0
0
1
•
17
R0[18]
12
0
0
1
•
16
11
15
0
0
1
•
DATA[20:0] FIELD
RF VCO Characteristics
14
(Continued)
RF Phase/
Frequency Detector
Polarity
10
0
0
1
•
13
Description
9
0
0
1
•
12
39
8
0
0
1
11
•
RF_R[14:0]
RF_R[14:0]
10
7
0
0
1
•
RF VCO Negative
Tuning
Characteristics
9
20053567
6
0
0
1
•
8
0
5
0
0
1
•
7
Function
6
4
0
0
1
•
RF VCO Positive
Tuning
Characteristics
5
3
0
0
1
•
4
1
2
0
1
1
•
3
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2
0
1
1
0
1
•
ADDRESS
FIELD
[2:0]
1
0
0
1
0
1
•
0
0