Reg Address
Bit Field
Type
Setting Name
Description
0x052B
1
R/W
FAST-
LOCK_MAN_PLLB
0: For normal operation
1: For force fast lock
Table 16.181. 0x052C DSPLL B Holdover Control
Reg Address
Bit Field
Type
Setting Name
Description
0x052C
0
R/W
HOLD_EN_PLLB
0: Holdover Disabled
1: Holdover Enabled
0x052C
3
R/W
HOLD_RAMP_BYP
_PLLB
Must be set to 1 for normal operation.
0x052C
4
R/W
HOLD_EX-
IT_BW_SEL1_PLLB
0: To use the fastlock loop BW when exiting from hold-
over
1: To use the normal loop BW when exiting from hold-
over
0x052C
7:5
R/W
RAMP_STEP_IN-
TERVAL_PLLB
Table 16.182. 0x052D
Reg Address
Bit Field
Type
Setting Name
Description
0x052D
1
R/W
HOLD_RAMP-
BYP_NOH-
IST_PLLB
Set by CBPro.
Table 16.183. 0x052E DSPLL B Holdover History Average Length
Reg Address
Bit Field
Type
Setting Name
Description
0x052E
4:0
R/W
HOLD_HIST_LEN_
PLLB
5-bit value
The holdover logic averages the input frequency over a period of time whose duration is determined by the history average length. The
average frequency is then used as the holdover frequency. See to calculate the window length from the register value. time = ((2
LEN
) –
1)*268nsec
Table 16.184. 0x052F DSPLLB Holdover History Delay
Reg Address
Bit Field
Type
Setting Name
Description
0x052F
4:0
R/W
HOLD_HIST_DE-
LAY_PLLB
5-bit value
The most recent input frequency perturbations can be ignored during entry into holdover. The holdover logic pushes back into the past.
The amount the average window is delayed is the holdover history delay. See to calculate the ignore delay time from the register value.
time = (2
DELAY
)*268nsec
Table 16.185. 0x0531
Reg Address
Bit Field
Type
Setting Name
Description
0x0531
4:0
R/W
HOLD_REF_COUN
T_FRC_PLLB
5- bit value
Si5397/96 Reference Manual
Si5397C/D Register Map
silabs.com
| Building a more connected world.
Rev. 0.9 | 227