AD9520-0 Analog Devices, Inc., AD9520-0 Datasheet - Page 69

• Manufacturer Part Number: AD9520-0
• Description: 12 Lvpecl/24 Cmos Output Clock Generator With Integrated 2.8 Ghz Vco
• Manufacturer: Analog Devices, Inc.

Reg.
Addr
(Hex) Bit(s) Name
016
016
017
[3]
[2:0] Prescaler P
[7:2] STATUS
B counter
bypass
pin control
B counter bypass. This is only valid when operating the prescaler in FD mode.
[3] = 0; normal (default).
[3] = 1; B counter is set to divide-by-1. This allows the prescaler setting to determine the divide for
the N divider.
Prescaler: DM = dual modulus and FD = fixed divide. The Prescaler P is part of the feedback divider.
[2]
0
0
0
0
1
1
1
1
Selects the signal that appears at the STATUS pin. 0x01D[7] must be 0 to reprogram the STATUS pin.
[7]
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Description
[1]
0
0
1
1
0
0
1
1
[6]
0
0
0
0
0
0
0
X
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
[0] Mode
0
1
0
1
0
1
0
1
[5] [4]
0
0
0
0
0
0
0
X
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
1
1
1
X
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
FD
FD
DM
DM
DM
DM
DM
FD
[3]
0
0
1
1
0
0
1
X
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
Rev. 0 | Page 69 of 84
Prescaler
Divide-by-1.
Divide-by-2.
Divide-by-2 and divide-by-3 when A ≠ 0; divide-by-2 when A = 0.
Divide-by-4 and divide-by-5 when A ≠ 0; divide-by-4 when A = 0.
Divide-by-8 and divide-by-9 when A ≠ 0; divide-by-8 when A = 0.
Divide-by-16 and divide-by-17 when A ≠ 0; divide-by-16 when A = 0.
Divide-by-32 and divide-by-33 when A ≠ 0; divide-by-32 when A = 0 (default).
Divide-by-3.
[2]
0
1
0
1
0
1
0
X
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
Level or
Dynamic
Signal
LVL
DYN
DYN
DYN
DYN
DYN
DYN
LVL
LVL
DYN
DYN
DYN
DYN
LVL
LVL
LVL
LVL
LVL
LVL
LVL
LVL
LVL
LVL
LVL
LVL
DYN
DYN
DYN
Signal at STATUS Pin
Ground, dc (default).
N divider output (after the delay).
R divider output (after the delay).
A divider output.
Prescaler output.
PFD up pulse.
PFD down pulse.
Ground (dc); for all other cases of 0XXXXX not specified.
The selections that follow are the same as for REFMON.
Ground (dc).
REF1 clock (differential reference when in differential mode).
REF2 clock (N/A in differential mode).
Selected reference to PLL (differential reference when in
differential mode).
Unselected reference to PLL (not available in differential
mode).
Status of selected reference (status of differential reference);
active high.
Status of unselected reference (not available in differential
mode); active high.
Status REF1 frequency (active high).
Status REF2 frequency (active high).
(Status REF1 frequency) AND (status REF2 frequency).
(DLD) AND (status of selected reference) AND (status of VCO).
Status of VCO frequency (active high).
Selected reference (low = REF1, high = REF2).
DLD; active high.
Holdover active (active high).
N/A internal holdover comparator output (active high).
VS (PLL power supply).
REF1 clock (differential reference when in differential mode).
REF2 clock (not available in differential mode).
Selected reference to PLL (differential reference when in
differential mode).
AD9520-0