8T49N287 Datasheet, PDF (17/75 Pages) Integrated Circuit Systems – Optional Fast Lock function

8T49N287 DATA SHEET
Table 6E. Digital PLL0 Input Control Register Bit Field Locations and Descriptions
Digital PLL0 Input Control Register Block Field Locations
Address (Hex)
D7
D6
D5
D4
D3
D2
0008
REFSEL0[2:0]
FBSEL0[1:0]
0009
11
10
PRI0_1[1:0]
000A
1
1
REFDIS0_1 REFDIS0_0
Rsvd
Rsvd
000B
Rsvd
PRE0_0[20:16]
000C
PRE0_0[15:8]
000D
PRE0_0[7:0]
000E
Rsvd
PRE0_1[20:16]
000F
PRE0_1[15:8]
0010
PRE0_1[7:0]
0011
Rsvd
Rsvd
0012
Rsvd
0013
Rsvd
0014
Rsvd
Rsvd
0015
Rsvd
0016
Rsvd
D1
D0
RVRT0 SWMODE0
PRI0_0[1:0]
STATE0[1:0]
Bit Field Name
REFSEL0[2:0]
FBSEL0[2:0]
RVRT0
SWMODE0
PRI0_0[1:0]
Field
Type
R/W
R/W
R/W
R/W
R/W
Digital PLL0 Input Control Register Block Field Descriptions
Default Value
000b
000b
1b
1b
00b
Description
Input reference selection for Digital PLL0:
000 = Automatic selection
001 = Manual selection by GPIO inputs
010 through 011 = Reserved
100 = Force selection of Input Reference 0
101 = Force selection of Input Reference 1
110 = Do not use
111 = Do not use
Feedback mode selection for Digital PLL0:
000 through 011 = internal feedback divider
100 = external feedback from Input Reference 0
101 = external feedback from Input Reference 1
110 = do not use
111 = do not use
Automatic switching mode for Digital PLL0:
0 = non-revertive switching
1 = revertive switching
Controls how Digital PLL0 adjusts output phase when switching between input references:
0 = Absorb any phase differences between old and new input references at the PLL output.
Recommended for use when both input references are in the same clock domain.
1 = Limit the maximum rate of phase change at the PLL output when adjusting to a new
input reference’s phase/frequency using phase-slope limiting as set in the SLEWn bits.
Recommended for use when the input references are not in the same clock domain.
Switchover priority for Input Reference 0 when used by Digital PLL0:
00 = 1st priority
01 = 2nd priority
10 = do not use
11 = do not use
REVISION 5 07/09/15
17
FEMTOCLOCK^® NG OCTAL UNIVERSAL FREQUENCY TRANSLATOR