Silicon Laboratories SI5368 Clock User Manual


 
Si53xx-RM
68 Rev. 0.5
6.3.2. Automatic Clock Selection (Si5322, Si5323, Si5365, Si5366)
The AUTOSEL input pin sets the input clock selection mode as shown in Table 24. Automatic switching is either
revertive or non-revertive. Setting AUTOSEL to M or H, changes the CSn_CAm pins to output pins that indicate the
state of the automatic clock selection (See Table 25 and Table 26). Digital hold is indicated by all CnB signals going
high after a valid ICAL.
The prioritization of clock inputs for automatic switching is shown in Table 27 and Table 28. This priority is
hardwired in the devices.
Table 24. Automatic/Manual Clock Selection
AUTOSEL Clock Selection Mode
L Manual (See Previous Section)
M Automatic Non-revertive
H Automatic Revertive
Table 25. Clock Active Indicators (AUTOSEL = M or H) (Si5322 and Si5323)
CS_CA Active Clock
0CKIN1
1CKIN2
Table 26. Clock Active Indicators (AUTOSEL = M or H) (Si5365 and Si5367)
CA1 CA2 CS0_CA3 CS1_CA4 Active Clock
1000CKIN1
0100CKIN2
0010CKIN3
0001CKIN4
Table 27. Input Clock Priority for Auto Switching (Si5322, Si5323)
Priority Input Clocks
1CKIN1
2CKIN2
3 Digital Hold