STC3800_15 Datasheet, PDF (41/48 Pages) Connor-Winfield Corporation – INTEGRATED - STRATUM 3E TIMING SOURCE

Application Notes continued
Sel0-3 - Write to the appropriate values for the desired reference selection and operating mode, as shown below:
(Note: Reference switches are performed in a hitless manner. However, if the application externally changes the
frequency of a particular reference, the device requires 20mS to auto-detect the new frequency. Manual switches to a
frequency changed reference should not be made during this interval.)
Reference / Mode
Free Run
Lock to Ref1
Lock to Ref2
Lock to Ref3
Lock to Ref4
Lock to Ref5
Lock to Ref6
Lock to Ref7
Lock to Ref8
Hold Over
Hardware Reference Selection and Mode Control
Table 12
Sel3
Sel2
Pin
Sel1
0
0
0
0
0
0
0
0
1
0
0
1
0
1
0
0
1
0
0
1
1
0
1
1
1
0
0
1
0
0
Sel0
0
1
0
1
0
1
0
1
0
1
LOS, LOL, and Hold_Rdy are status indication outputs. Their use is at the discretion of the application. See Phase Lock
Operation and Pin Description sections for details of their operation.
In Hardware Control mode, the Sync_8K and Sync_2K signals default to 50% duty cycle, and PLL bandwidth/ phase
buildout default to stratum 3. Therefore, Stratum 3E operation requires use of register access.
Preliminary Data Sheet #: TM061 Page 41 of 48 Rev: P06 Date: 11/22/04
© Copyright 2001 The Connor-Winfield Corp. All Rights Reserved Specifications subject to change without notice