Reg Address
Bit Field
Type
Setting Name
Description
0x0722
4
R/W
M_FRAC_EN_PLL
D
M feedback divider fractional enable.
0: Integer-only division
1: Fractional (or integer) division - Required for DCO
operation.
0x0722
5
R/W
Reserved
Must be set to 1 for DSPLL D
Table 15.254. 0x0723 DSPLL D FINC/FDEC Control
Reg Address
Bit Field
Type
Setting Name
Description
0x0723
0
R/W
M_FSTEP_MSK_P
LLD
0: To enable FINC/FDEC updates
1: To disable FINC/FDEC updates
0x0723
1
R/W
M_FSTEPW_DEN_
PLLD
0: Modify numerator
1: Modify denominator
Table 15.255. 0x0724-0x072A DSPLLD MD Divider Frequency Step Word
Reg Address
Bit Field
Type
Setting Name
Description
0x0724
7:0
R/W
M_FSTEPW_PLLD 56-bit number
0x0725
15:8
R/W
M_FSTEPW_PLLD
0x0726
23:16
R/W
M_FSTEPW_PLLD
0x0727
31:24
R/W
M_FSTEPW_PLLD
0x0728
39:32
R/W
M_FSTEPW_PLLD
0x0729
47:40
R/W
M_FSTEPW_PLLD
0x072A
55:48
R/W
M_FSTEPW_PLLD
The frequency step word (FSTEPW) for the feedback M divider of DSPLL D is always a positive integer. The FSTEPW value is either
added to or subtracted from the feedback M divider Numerator such that an FINC will increase the output frequency and an FDEC will
decrease the output frequency. See also Registers 0x0716–0x0720.
Table 15.256. 0x072B DSPLL D Input Clock Select
Reg Address
Bit Field
Type
Setting Name
Description
0x072B
2:0
R/W
IN_SEL_PLLD
0: For IN0
1: For IN1
2: For IN2
3: For IN3
4–7: Reserved
This is the input clock selection for manual register based clock selection.
Si5397/96 Reference Manual
Si5397A/B Register Map
silabs.com
| Building a more connected world.
Rev. 0.9 | 162