Datasheet

Data Sheet AD9559
Rev. C | Page 91 of 120
DPLL_1 CONTROLS (REGISTER 0x0500 TO REGISTER 0x0515)
Table 108. DPLL_1 Free Run Frequency Tuning Word
Address Bits Bit Name Description
0x0500
[7:0]
30-bit free running frequency tuning word
Free running frequency tuning word, Bits[7:0] (default: 0x12)
0x0501 [7:0] Free running frequency tuning word, Bits[15:8] (default: 0x15)
0x0502 [7:0] Free running frequency tuning word, Bits[23:9] (default: 0x64)
0x0503 [7:6] Reserved Default: 00b
[5:0] 30-bit free running frequency word Free running frequency tuning word, Bits[29:24] (default: 0x1B)
Table 109. DPLL_1 Digital Oscillator Control
Address
Bits
Bit Name
Description
0x0504
[7:5]
Reserved
Default: 0x0
[4:0] Digital oscillator SDM integer part 0000 to 0011 = invalid
0100 = divide-by-4
0101 = invalid
0110 = divide-by-6
0111 = divide-by-7
1000 = divide-by-8 (default)
1001 = divide-by-9
1010 = divide-by-10
1011 = divide-by-11
1100 = divide-by-12
1101 = divide-by-13
1110 = divide-by-14
1111 = divide-by-15
Table 110. DPLL_1 Frequency Clamp
Address Bits Bit Name Description
0x0505 [7:0] Lower limit of pull-in range
(expressed as a 20-bit frequency
tuning word)
Lower limit pull-in range, Bits[7:0]
Default: 0x51
0x0506 [7:0] Lower limit pull-in range, Bits[15:8]
Default: 0xB8
0x0507 [7:4] Reserved Default: 0x0
[3:0] Lower limit of pull-in range Lower limit pull-in range, Bits[19:16]
Default: 0x2
0x0508
[7:0]
Upper limit of pull-in range
(expressed as a 20-bit frequency
tuning word)
Upper limit pull-in range, Bits[7:0]
Default: 0x3E
0x0509 [7:0] Upper limit pull-in range, Bits[15:8]
Default: 0x0A
0x050A [7:4] Reserved Default: 0x0
[3:0] Upper limit of pull-in range Upper limit pull-in range, Bits[19:16]
Default: 0xB
Table 111. DPLL_1 History Accumulation Timer
Address Bits Bit Name Description
0x050B [7:0] History accumulation timer
(expressed in units of ms)
History accumulation timer, Bits[7:0].
Default: 0x0A.
For Register 0x050B and Register 0x050C, 0x000A = 10 ms. Maximum: 65 sec.
This register controls the amount of tuning word averaging used to
determine the tuning word used in holdover. Never program a timer value of 0.
Default value: 0x000A = 10 (10 ms).
0x050C [7:0] History accumulation timer, Bits[15:8].
Default: 0x00.