We would like to measure a settring time of HMC830 using Eva. kit. How should we measure the settring time of only HMC830? This means we would like to remove calculation time for PC (GUI) and FPGA(USB board).
Once the HMC830 is locked there is no need to update registers other then those registers involved with frequency control (Reg 0x03, Reg 0x04 and the output divider). If you choose to send a complete configuration there is no difference in PLL settling time but you will add extra time to transfer redundant register information.
PLL settling time is defined as the time to lock after updating either Register 0x03 (in integer mode) or Register 0x04 (in fractional mode). These two registers should always be updated last when sending a complete configuration.
We use the 5052B phase noise analyzer to measure settling time. Trigger the measurement using the 5052B narrowband trigger. The cursor is set to when the output phase has settled to some value. In this example we use 10 degrees which gives a settling time of 118us.
Thank you for you answer. Let me take a reference.
By the way, as for GUI of PLL evaluation softwaer,
Does it have a frequency hoping fanction? I think that the old version of the GUI has the function. I can not find the function in the latest version.
As for register setting,
Can we set only some parts of register (e.g. only Regh 03h and 04h) after sending all register setting?
If yes, is there differentce response time between all register sending and part of resister sending?
How can we send a part of resister by GUI? Is it "write" button of "Detailed GUI" of the GUI?
Thanks & Regards,
Previous versions of the control GUI included frequency hop capability but we removed this function. It was not possible to control hop time accurately under the Eval software .NET architecture.
The "SPI read/write" buttons can write any particular register after sending the complete configuration. The buttons are identical and allow two simultaneous windows open. If you want to update two or more registers just create another configuration file with the subset of the full configuration. The register configuration files are just text files -- you can modify them as you wish but you can not write a partial register.
The "Show R/W Regs History" window logs all register accesses. You can use this window to see exactly what information is passed between the GUI and HMC830.
For example the syntax "R &H3 &H32" indicates register 0x03 was read with a value of 0x32. All other text is informational. If you leave this window open and play with the software you will see many unexpected register transfers. We haven't optimized the GUI to minimize the number of register accesses. For example just refocusing the mouse on the GUI window triggers 10 reads and 2 writes. Changing frequency only requires a maximum of 3 writes but the GUI "update frequency" button triggers the following:
11:43:16 AM --> // VCO freq button pressed - BEGIN --------------
11:43:16 AM --> R &H5 &H6090 readlng Read
11:43:16 AM --> W &H5 &H6090 REGSET_87797 set_vco_to_out_divider
11:43:16 AM --> R &H9 &H547FFF
11:43:16 AM --> W &H9 &H547FFF
11:43:16 AM --> W &HC &H0
11:43:16 AM --> // Set FRAC Mode - BEGIN ------------------------
11:43:16 AM --> R &H6 &H200B4A setbit Read
11:43:16 AM --> W &H6 &H200B4A setbit Write
11:43:16 AM --> // Set FRAC Mode - END --------------------------
11:43:16 AM --> R &H2 &H1 readlng Read
11:43:16 AM --> R &H2 &H1 setlng Read
11:43:16 AM --> W &H2 &H1 setlng Write
11:43:16 AM --> R &H8 &HC1BEFF readbit Read
11:43:16 AM --> W &H3 &H32 REGSET_87797 set_intg_register
11:43:16 AM --> W &H5 &H0 REGSET_87797 vco_setcap
11:43:16 AM --> W &H4 &H0 REGSET_87797 set_frac_register
11:43:16 AM --> R &H5 &H0 readlng Read
11:43:16 AM --> R &H6 &H200B4A readbit Read
11:43:16 AM --> R &H4 &H0 REGSET_87797 get_frac_register
11:43:16 AM --> R &H3 &H32 REGSET_87797 get_intg_register
11:43:17 AM --> R &H0 &HA7975 Read CHIP_ID from the chip
11:43:17 AM --> R &H7 &H14D REGSET_87797 get_lockdet_en
11:43:17 AM --> R &H12 &H3 readbit Read
11:43:17 AM --> R &H2 &H1 readlng Read
11:43:17 AM --> R &H3 &H32 REGSET_87797 get_intg_register
11:43:17 AM --> R &H4 &H0 REGSET_87797 get_frac_register
11:43:17 AM --> // VCO freq button pressed - END ----------------
All this is done to insure GUI fields represent a true state of the hardware.
Thank you for your detailed explanation.
And I would like to know that,
Is there a difference about responce time betweem sending the complete configuration and sending one or something part of resistor? Responce time means time period from register sending to PLL lock.
Thanks & Regards,
I would like to know that the responce time in case of sending the complete configuration and in case of sending one or something parts of resistor (= not complete) are same time or not.
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