HMC7044 Datasheet, PDF (57/72 Pages) Analog Devices – JESD204B clock generation

Data Sheet
HMC7044
Table 44. PLL1 Reference Switching Control
Address Bits Bit Name
0x0029 [7:6] Reserved
5 Bypass debouncer
[4:3] Manual Mode Reference
Switching[1:0]
2 Holdover uses DAC
1 Autorevertive reference
switching
0 Automode reference switching
Settings
0
1
Description
Reserved
Bypass the debouncer in manual mode and GPI clock/holdover
selection
If automode REF switching = 0, manual selection of
CLKINx/CLKINx input
In holdover, selects whether PLL1 uses the DAC or tristates the
charge pump
Tristate the charge pump
Use holdover DAC
Revert to PLL1 best clock option if it becomes available again
Clock switching is automatic based on LOS/PLL1 reference
priority control register (Register 0x0014)
Access
RW
Table 45. PLL1 Holdoff Time Control
Address Bits Bit Name
Settings
0x002A [7:0] Holdoff Timer[7:0]
Description
PLL1 waits in holdover for 2^{Holdoff Timer[7:0]} LCM cycles to give the abandoned
reference a chance to recover before switching to the next priority clock. If
Holdoff Timer[7:0] equals to 0, holdoff functionality is disabled and switches
directly to the next priority clock.
Access
RW
PLL2 (Register 0x0031 to Register 0x003C)
Table 46. PLL2 Miscellaneous Control
Address
Bits
Bit Name
0x0031
[7:0]
Reserved
0x003C
[7:0]
Reserved
Settings
Description
Reserved
Reserved
Access
RW
RW
Table 47. PLL2 Frequency Doubler Control
Address Bits Bit Name
0x0032
[7:1] Reserved
0
Bypass frequency doubler
Settings
0
1
Description
Reserved
Bypass PLL2 frequency doubler
Enable frequency doubler before R2 divider
Bypass frequency doubler
Access
RW
Table 48. PLL2 Reference Divider Control (R2)
Address Bits Bit Name
Settings
0x0033 [7:0] 12-Bit R2 Divider[7:0]
(LSB)
0x0034 [7:4] Reserved
[3:0] 12-Bit R2 Divider[11:8]
(MSB)
Description
12-bit R2 divider setpoint LSB. Divide by 1 to divide by 4095. 00000000,
00000001 = divide by 1.
Reserved.
12-Bits R2 divider setpoint MSB.
Access
RW
RW
Table 49. PLL2 Feedback Divider Control (N2)
Address Bits Bit Name
0x0035 [7:0] 16-Bit N2 Divider[7:0] (LSB)
0x0036 [7:0] 16-Bit N2 Divider[15:8] (MSB)
Settings
Description
16-bit N2 divider setpoint LSB.
16-bit N2 divider setpoint MSB.
Access
RW
RW
Rev. B | Page 57 of 72