AD9546
Recommended for New Designs
The AD9546 incorporates digitized clocking technology that efficiently transports and distributes clock signals in systems. Digitized clocking allows the...
Datasheet
AD9546 on Analog.com
Hello,
We are trying to load a register map from MCU to AD9546 through I2C bus. What I did, I have explained below.
1) I have exported a JSON file from AD9546 Evaluation Software.
2) I am able to work with AD9546 Evaluation Software with my EVK board and custom board. It works definitely.
2) From JSON File, i have extracted the "RegisterMap" field.
3) I have created an array and send to the AD9546(10MHz RefA, 48MHz SysCLK, 1Hz desired output) from MCU through I2C bus.
4) I am applying the IO update as well.
Results;
I can read the temperature but I am not able to see 1 Hz as output from my custom board. What can be the main problem ? Which registers I should check that I have to be sure everything goes well ?
I have attached the logic analyzer output and JSON file.
https://drive.google.com/drive/folders/1LAMPJVR2sspkcD8G074_-dv7ZFOS4BZG?usp=sharing
I would appreciate any help.
Thanks.
HI,
I clicked on the link you provided, but I arrived here and it does not seem to be any file there:
I would have liked to verify the json file. You say you were able to connect the eval software to the eval board and to your board and it worked. So I assume it's OK.
If you then tried to download yourself the configuration into the AD9546 using I2C and the configuration did not work, you may try this:
- to make sure the I2C read and write operations work, first read registers like 0x0003, 0x0004, 0x0005, 0x0006, 0x000B and 0x000C that have non-zero default values. After you are able to read those, write a scratchpad register 0x0020 to 0x0023 with non zero values. See if you can read back the imposed values.
- after you are sure the read and write I2C operations work, use the Initialization procedure from the page 196 in the data sheet. Make sure you follow it.
- After you write the registers and execute IO Update, read the registers back and see if the values you imposed are now live into the chip.
-then move on with the next steps in the initialization procedure.
Petre
HI,
if you are able to read and write scratchpad registers, then the I2C operations should be fine. Do you follow the initialization procedure from the data sheet?
When I was talking about reading back registers, I was referring to reading back the configuration registers. The status registers or registers that are updated by the AD9545 with the real time information like the DPLL tuning word history change their values continuously.
I looked at the json file you sent and I see that:
- the system clock source is a 48 MHz crystal resonator, so you changed the 52 MHz crystal on the eval board. Note that if the configuration is set with one frequency and the reality is different, the AD9546 cannot be expected to run correctly.
- DPLLs are set with 50mHz loop bandwidth. Not clear why as you set them in phase buildout and the wizard accepts 50 Hz bandwidth.
- you say you do not get outputs. There may be two reasons: The auto sync mode is disabled, so you need either to set it to immediate, or to generate an IO Update.
The outputs are set as CML and the eval board is set as HCSL. Verify your schematic and match the schematic with the configuration.
Petre
Hi,
you say " I have looked to the initialization sequence but I dont know exactly what should I do after loading the register map and io updating ?"
You need to initialize the system clock PLL and the APLL0 and APLL1. You may not obtain outputs because the APLL0 and APLL1 are not locked.
See figures 133 and 134 for detailed information about how to do these steps.
Your colleague used the eval software to configure the AD9546 and it worked. The eval software uses SPI, but the key point is that the eval software executes the initialization of the system clock PLL and APLL0 and APLL1 automatically.
You need to execute these steps with the I2C as well.
Petre
