S i 5 3 x x - R M
82
Rev. 0.52
If the selected clock enters an alarm condition, the PLL enters digital hold mode. The
CKSEL_REG
[1:0] controls
are ignored if automatic clock selection is enabled.
7.4.2. Automatic Clock Selection (Si5324, Si5325, Si5326, Si5367, Si5368, Si5369, Si5374)
The
AUTOSEL_REG
[1:0] register bits sets the input clock selection mode as shown in Table 40. Automatic
switching is either revertive or non-revertive.
CKSEL_PIN is of significance only when Manual is selected.
7.4.2.1. Detailed Automatic Clock Selection Description (Si5324, Si5325, Si5326, Si5374)
Automatic switching is either revertive or non-revertive. The default prioritization of clock inputs when the device is
configured for automatic switching operation is CKIN1, followed by CKIN2, and finally, digital hold mode. The
inverse input clock priority arrangement is available through the CK_PRIOR bits, as shown in the Si5325, Si5326,
and Si5374.
For the default priority arrangement, automatic switching mode selects CKIN1 at powerup, reset, or when in
revertive mode with no alarms present on CKIN1. If an alarm condition occurs on CKIN1 and there are no active
alarms on CKIN2, then the device switches to CKIN2. If both CKIN1 and CKIN2 are alarmed, then the device
enters digital hold mode. If automatic mode is selected and the frequency offset alarms (
FOS1_INT
and
FOS2_INT
) are disabled, automatic switching is not initiated in response to FOS alarms. The loss-of-signal alarms
(
LOS1_INT
and
LOS2_INT
) are always used in making automatic clock selection choices.
In non-revertive mode, once CKIN2 is selected, CKIN2 selection remains as long as it is valid even if alarms are
cleared on CKIN1.
Table 39. Manual Input Clock Selection (Si5324, Si5325, Si5326, Si5374)
CKSEL_REG or CS pin
Active Input Clock
0
CKIN1
1
CKIN2
Table 40. Automatic/Manual Clock Selection
AUTOSEL_REG[1:0]
Clock Selection Mode
00
Manual
01
Automatic Non-revertive
10
Automatic Revertive
11
Reserved
Содержание Si5316 Series
Страница 2: ...Si53xx RM 2 Rev 0 52 ...
Страница 109: ...Si53xx RM Rev 0 52 109 8 3 Typical Scope Shots for SFOUT Options Figure 46 sfout_2 CMOS Figure 47 sfout_3 lowSwingLVDS ...
Страница 110: ...Si53xx RM 110 Rev 0 52 Figure 48 sfout_5 LVPECL Figure 49 sfout_6 CML ...
Страница 111: ...Si53xx RM Rev 0 52 111 Figure 50 sfout_7 LVDS ...
Страница 127: ...Si53xx RM Rev 0 52 127 Figure 66 155 52 MHz In 622 08 MHz Out Loop BW 7 Hz Si5324 ...
Страница 128: ...Si53xx RM 128 Rev 0 52 Figure 67 19 44 MHz In 156 25 MHz Out Loop BW 80 Hz ...
Страница 129: ...Si53xx RM Rev 0 52 129 Figure 68 19 44 MHz In 156 25 MHz Out Loop BW 5 Hz Si5324 ...
Страница 130: ...Si53xx RM 130 Rev 0 52 Figure 69 27 MHz In 148 35 MHz Out Light Trace BW 6 Hz Dark Trace BW 110 Hz Si5324 ...
Страница 131: ...Si53xx RM Rev 0 52 131 Figure 70 61 44 MHz In 491 52 MHz Out Loop BW 7 Hz Si5324 ...
Страница 132: ...Si53xx RM 132 Rev 0 52 Figure 71 622 08 MHz In 672 16 MHz Out Loop BW 6 9 kHz ...
Страница 133: ...Si53xx RM Rev 0 52 133 Figure 72 622 08 MHz In 672 16 MHz Out Loop BW 100 Hz ...
Страница 134: ...Si53xx RM 134 Rev 0 52 Figure 73 156 25 MHz In 155 52 MHz Out ...
Страница 139: ...Si53xx RM Rev 0 52 139 Figure 78 86 685 MHz In 173 371 MHz Out ...
Страница 140: ...Si53xx RM 140 Rev 0 52 Figure 79 86 685 MHz In 693 493 MHz Out ...
Страница 142: ...Si53xx RM 142 Rev 0 52 Figure 81 10 MHz In 1 GHz Out ...
Страница 174: ...Si53xx RM 174 Rev 0 52 Figure 99 Si5374 Si5375 DSPLL A ...
Страница 175: ...Si53xx RM Rev 0 52 175 Figure 100 Si5374 Si5375 DSPLL B ...
Страница 176: ...Si53xx RM 176 Rev 0 52 Figure 101 Si5374 Si5375 DSPLL C ...