Si53xx-RM
Rev. 0.52
73
6.9.3. FSYNC Align Alarm (Si5366 and CK_CONF = 1 and FRQTBL = L)
At power-up or any time after the PLL has lost lock and relocked, the device automatically performs a realignment
of FS_OUT using the currently active sync input. After this, as long as the PLL remains in lock and a realignment is
not requested, FS_OUT will include a fixed number of high-speed clock cycles, even if input clock switches are
performed. If many clock switches are performed, it is possible that the input sync to output sync phase relationship
will shift due to the accumulated residual phase transients of the phase build-out circuitry. The internal ALIGN_INT
signal is asserted when the accumulated phase errors exceeds two cycles of CKOUT2.
6.9.4. C1B and C2B Alarm Outputs (Si5316, Si5322, Si5323)
The alarm outputs (C1B and C2B) are determined directly by the LOS1_INT and LOS2_INT internal indicators
directly. That is C1B = LOS1 and C2B = LOS2.
6.9.5. C1B, C2B, C3B, and ALRMOUT Outputs (Si5365, Si5366)
The alarm outputs (C1B, C2B, C3B, ALRMOUT) provide a summary of various alarm conditions on the input clocks
depending on the setting of the FOS_CNTL and CK_CONF pins.
The following internal alarm indicators are used in determining the output alarms:
LOSn_INT: See section “6.9.1. Loss-of-Signal Alarms (Si5316, Si5322, Si5323, Si5365, Si5366)” for a
description of how LOSn_INT is determined
FOSn_INT: See section “6.9.2. FOS Alarms (Si5365 and Si5366)”for a description of how FOSn_INT is
determined
ALIGN_INT: See section “6.9.3. FSYNC Align Alarm (Si5366 and CK_CONF = 1 and FRQTBL = L)” for a
description of how ALIGN_INT is determined
Based on the above internal signals and the settings of the CK_CONF and FOS_CTL pins, the outputs C1B, C2B,
C3B, ALRMOUT are determined (See
Table 33). For details, see "Appendix D—Alarm Structure" on page 144.
.
Table 32. Frequency Offset Control (FOS_CTL)
FOS_CNTL
Meaning
L
FOS Disabled.
M
Stratum 3/3E FOS Threshold (12 ppm)
H
SONET Minimum Clock Threshold (48 ppm)
Table 33. Alarm Output Logic Equations
CK_CONF
FOS_CTL
Alarm Output Equations
0
Four independent input
clocks
L
(Disables FOS)
C1B =
LOS1_INT
C2B =
LOS2_INT
C3B =
LOS3_INT
ALRMOUT =
LOS4_INT
M or H
C1B =
LOS1_INT
or
FOS1_INT
C2B =
LOS2_INT
or
FOS2_INT
C3B =
LOS3_INT
or
FOS3_INT
ALRMOUT =
LOS4_INT
or
FOS4_INT
1
(FSYNC switching
mode)
L
(Disables FOS)
C1B =
LOS1_INT
or (
LOS3_INT
and FSYNC_SWTCH)
C2B =
LOS2_INT
or (
LOS4_INT
and FSYNC_SWTCH)
C3B = tri-state
ALRMOUT =
ALIGN_INT
M or H
C1B =
LOS1_INT
or (
LOS3_INT
and FSYNC_SWTCH) or
FOS1_INT
C2B =
LOS2_INT
or (
LOS4_INT
and FSYNC_SWTCH) or
FOS2_INT
C3B = tri-state
ALRMOUT =
ALIGN_INT
Summary of Contents for Si5316 Series
Page 2: ...Si53xx RM 2 Rev 0 52 ...
Page 110: ...Si53xx RM 110 Rev 0 52 Figure 48 sfout_5 LVPECL Figure 49 sfout_6 CML ...
Page 111: ...Si53xx RM Rev 0 52 111 Figure 50 sfout_7 LVDS ...
Page 127: ...Si53xx RM Rev 0 52 127 Figure 66 155 52 MHz In 622 08 MHz Out Loop BW 7 Hz Si5324 ...
Page 128: ...Si53xx RM 128 Rev 0 52 Figure 67 19 44 MHz In 156 25 MHz Out Loop BW 80 Hz ...
Page 129: ...Si53xx RM Rev 0 52 129 Figure 68 19 44 MHz In 156 25 MHz Out Loop BW 5 Hz Si5324 ...
Page 131: ...Si53xx RM Rev 0 52 131 Figure 70 61 44 MHz In 491 52 MHz Out Loop BW 7 Hz Si5324 ...
Page 132: ...Si53xx RM 132 Rev 0 52 Figure 71 622 08 MHz In 672 16 MHz Out Loop BW 6 9 kHz ...
Page 133: ...Si53xx RM Rev 0 52 133 Figure 72 622 08 MHz In 672 16 MHz Out Loop BW 100 Hz ...
Page 134: ...Si53xx RM 134 Rev 0 52 Figure 73 156 25 MHz In 155 52 MHz Out ...
Page 139: ...Si53xx RM Rev 0 52 139 Figure 78 86 685 MHz In 173 371 MHz Out ...
Page 140: ...Si53xx RM 140 Rev 0 52 Figure 79 86 685 MHz In 693 493 MHz Out ...
Page 142: ...Si53xx RM 142 Rev 0 52 Figure 81 10 MHz In 1 GHz Out ...
Page 174: ...Si53xx RM 174 Rev 0 52 Figure 99 Si5374 Si5375 DSPLL A ...
Page 175: ...Si53xx RM Rev 0 52 175 Figure 100 Si5374 Si5375 DSPLL B ...
Page 176: ...Si53xx RM 176 Rev 0 52 Figure 101 Si5374 Si5375 DSPLL C ...