LMX2364 National Semiconductor Corporation, LMX2364 Datasheet - Page 27

• Manufacturer Part Number: LMX2364
• Description: 2.6 Ghz Pllatinum Fractional Rf Frequency Synthesizer With 850 Mhz Integer If Frequency Synthesizer
• Manufacturer: National Semiconductor Corporation

Reg
R2
Programming Description
2.5 R2 REGISTER
The R2 Register is used to setup the FastLock circuitry for the IF synthesizer.
2.5.1 IF_TOC[13:0] — FastLock Timeout Counter, IF Synthesizer
The IF_TOC[13:0] word controls the operation of the IF FastLock circuitry as well as the function of the FLoutIF output pin. When
IF_TOC is set to a value between 0 and 3, the IF timeout counter is disabled and the FLoutIF pin operates as a general purpose
I/O pin. When IF_TOC is set to a value between 4 and 16383, the IF FastLock mode is enabled and FLoutIF is utilized as the IF
FastLock output pin. The value programmed into IF_TOC represents the number of phase comparison cycles that the IF
synthesizer will spend in the FastLock state.
IF_TOC[13:0]
23
0
16,383
…
22
0
0
1
2
3
4
21
0
20
0
FastLock Mode
19
0
Disabled
Disabled
Disabled
Enabled
Enabled
Enabled
Manual
18
0
17
0
16
(Continued)
15
FastLock Period
[CP Events]
14
16383
DATA[20:0]
N/A
N/A
N/A
…
3
4
13
12
27
11
IF_TOC[13:0]
Logic LOW State. Force IF Charge Pump to 800 µA
10
9
FLoutIF Pin Functionality
8
Logic HIGH State
Logic LOW State
High Impedance
7
FastLock
FastLock
FastLock
6
5
4
3
C2
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2
0
C1
1
1
C0
0
0