402-00005-00
DAC and PLL Programming
4–10
Rev 02; February 8, 2002
4.2.9 PLL Register 5 (PLLA5) R/W
0
7
PLL Address 0x5
PDB1
PDB0
PDA1
PDA0
SWLW
ADD
FBKPOL
FBKSEL
8
15
Reserved
Reserved
Reserved
Reserved
Reserved
1
FINEEN
LDLG
PCR_PLLA5_16
This register controls the PLL feedback divider. Bit 10 in this register must always be one.
Bit
Mnemonic
Function
0
FBKSEL
Feedback Select
1
FBKPOL
Feedback Polarity
2
ADD
Addition of 1 VCO Cycle
3
SWLW
Removal of 1 VCO Cycle
5–4
PDA
Output Post Scaler
7–6
PDB
Feedback Post Scaler
8
LDLG
Fine Phase Adjust Lead/Lag
9
FINEEN
Fine Phase Adjust Enable
10
Reserved
Must be one
15–11
Reserved
Don’t care
4.2.9.1 Feedback Select (FBKSEL) R/W
This bit selects internal feedback mode of the PLL. Default setting is 1. Always program this bit to one.
FBKSEL
Function
0
External feedback not supported
1
Internal Feedback selected
4.2.9.2 Feedback Polarity (FBKPOL) R/W
This bit selects the polarity of the external feedback signal if selected by FBKSEL. Defaults setting is 0.
FBKPOL
Function
0
Positive Edge default
1
Negative Edge
4.2.9.3 Addition of 1 VCO cycle (ADD) R/W
This bit is used to fine adjust the PLL. Toggle this bit from 0 to 1 to 0 to add one VCO cycle. The default setting is
zero.
4.2.9.4 Removal of 1 VCO cycle (SWLW) R/W
This bit is used to fine adjust the PLL. Toggle this bit from 0 to 1 to 0 to remove one VCO cycle. The default setting is
zero.
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