Si5345-44-42-D-RM
118
Rev. 1.0
Si5345
Input clock selection for manual register based and pin controlled clock selection. Note: when ZDM_EN (0x0487,
bit 0) and IN_SEL_REGCTRL are both high, IN_SEL does not do anything and the clock selection is pin controlled.
When IN_SEL_REGCTRL is low, IN_SEL does not do anything and the clock selection is pin controlled.
When in fast lock, the fast lock loop BW can be automatically used.
Register 0x052A Input Clock Select
Reg Address
Bit Field
Type
Name
Description
0x052A
0
R/W
IN_SEL_REGCTRL
0 for pin controlled clock selection
1 for register controlled clock selection
0x052A
2:1
R/W
IN_SEL
0 for IN0, 1 for IN1,
2 for IN2, 3 for IN3 (or FB_IN)
Register 0x052B Fast Lock Control
Reg Address
Bit Field
Type
Name
Description
0x052B
0
R/W
FASTLOCK_AUTO_EN
Applies only when
FASTLOCK_MAN = 0 (see below):
0 to disable auto fast lock when the
DSPLL is out of lock.
1 to enable auto fast lock.
0x052B
1
R/W
FASTLOCK_MAN
0 for normal operation (see above)
1 to force fast lock
Register 0x052C Holdover Exit Control
Reg Address Bit Field Type
Setting Name
Description
0x052C
0
R/W
HOLD_EN
Holdover enable
0: Holdover Disabled
1: Holdover Enabled (default)
0x052C
3
R/W
HOLD_RAMP_BYP
HOLD_RAMP_BYP
0x052C
4
R/W
HOLDEXIT_BW_SEL1
Holdover Exit Bandwidth select. Selects the exit
bandwidth from Holdover when ramped exit is
disabled (HOLD_RAMP_BYP = 1).
0: Exit Holdover using Holdover Exit or Fastlock
bandwidths (default). See HOLDEXIT_BW_-
SEL0 (0x059B[6]) for additional information.
1: Exit Holdover using the Normal loop band-
width
0x052C
7:5
R/W
RAMP_STEP_INTERVAL Time Interval of the frequency ramp steps when
ramping between inputs or when exiting hold-
over. Calculated by CBPro based on selection.