Silicon Laboratories SI5374 User Manual
S i 5 3 x x - R M
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.
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.
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
0
CKIN1
1
CKIN2
Table 26. Clock Active Indicators (AUTOSEL = M or H) (Si5365 and Si5367)
CA1
CA2
CS0_CA3
CS1_CA4
Active Clock
1
0
0
0
CKIN1
0
1
0
0
CKIN2
0
0
1
0
CKIN3
0
0
0
1
CKIN4
Table 27. Input Clock Priority for Auto Switching (Si5322, Si5323)
Priority
Input Clocks
1
CKIN1
2
CKIN2
3
Digital Hold