Si5345-44-42-D-RM
88
Rev. 1.0
Si5345
Input 0 (IN0): LOS_EN[0]
Input 1 (IN1): LOS_EN[1]
Input 2 (IN2): LOS_EN[2]
Input 3 (IN3): LOS_EN[3]
When an input clock is gone (and therefore has an active LOS alarm), if the clock returns, there is a period of time
that the clock must be within the acceptable range before the alarm is removed. This is the LOS_VAL_TIME.
ClockBuilder Pro calculates the correct LOS register threshold trigger value for Input 0, given a particular frequency
plan.
Register 0x002C LOS Enable
Reg Address
Bit Field
Type
Name
Description
0x002C
3:0
R/W
LOS_EN
1 to enable LOS for a clock input;
0 for disable
0x002C
4
R/W
LOSXAXB_DIS
Enable LOS detection on the XAXB
inputs.
0: Enable LOS Detection (default)
1: Disable LOS Detection
Register 0x002D Loss of Signal Re-Qualification Value
Reg Address
Bit Field
Type
Name
Description
0x002D
1:0
R/W
LOS0_VAL_TIME
Clock Input 0
0 for 2 msec
1 for 100 msec
2 for 200 msec
3 for one second
0x002D
3:2
R/W
LOS1_VAL_TIME
Clock Input 1, same as above
0x002D
5:4
R/W
LOS2_VAL_TIME
Clock Input 2, same as above
0x002D
7:6
R/W
LOS3_VAL_TIME
Clock Input 3, same as above
Register 0x002E-0x002F LOS0 Trigger Threshold
Reg Address
Bit Field
Type
Name
Description
0x002E
7:0
R/W
LOS0_TRG_THR
16-bit Threshold Value
0x002F
15:8
R/W
LOS0_TRG_THR