Table 15.155. 0x043A Hitless Switching Mode
Reg Address
Bit Field
Type
Setting Name
Description
0x043A
1:0
R/W
HSW_MODE_PLLA 1: Default setting, do not modify
0,2,3: Reserved
0x043A
3:2
R/W
HSW_PHMEAS_CT
RL_PLLA
0: Default setting, do not modify
1,2,3: Reserved
Table 15.156. 0x043B-0x043C Hitless Switching Phase Threshold
Reg Address
Bit Field
Type
Setting Name
Description
0x043B
7:0
R/W
HSW_PHMEAS_TH
R_PLLA
Set by CBPro.
0x043C
9:8
R/W
HSW_PHMEAS_TH
R_PLLA
Table 15.157. 0x043D
Reg Address
Bit Field
Type
Setting Name
Description
0x043D
4:0
R/W
HSW_COARSE_P
M_LEN_PLLA
Set by CBPro
Table 15.158. 0x043E
Reg Address
Bit Field
Type
Setting Name
Description
0x043E
4:0
R/W
HSW_COARSE_P
M_DLY_PLLA
Set by CBPro
Table 15.159. 0x043F DSPLL A Hold Valid History and Fastlock Status
Reg Address
Bit Field
Type
Setting Name
Description
0x043F
1
R
HOLD_HIST_VAL-
ID_PLLA
Holdover Valid historical frequency data indicator.
0: Invalid Holdover History - Freerun on input fail or
switch
1: Valid Holdover History - Holdover on input fail or
switch
0x043F
2
R
FASTLOCK_STA-
TUS_PLLA
Fastlock engaged indicator.
0: DSPLL Loop BW is active
1: Fastlock DSPLL BW currently being used
When the input fails or is switched and the DSPLL switches to Holdover or Freerun mode, HOLD_HIST_VALID_PLLA accumulation will
stop.
When a valid input clock is presented to the DSPLL, the holdover frequency history measurements will be cleared and will begin to
accumulate once again.
Si5397/96 Reference Manual
Si5397A/B Register Map
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