Two FMC150 board on one KC705 board to use the same clock
started a topic
about 4 years ago
We need to use 4 channel ADC and DAC. So we are going to put two FMC150 boards on one KC705. One is on HPC and the other is on LPC. When we put two FMC150 boards on one KC705 board by HPC and LPC, we need HPC board and LPC board to use the same clock. That is, HPC and LPC's clock should have the same frequency with a fixed offset. In this way, the four ADC and four DAC on the two boards basically have the same clock.
One way to do this is that LPC board provides clock (CLK_LPC) to the FPGA (sysclk_p, LOC = AD12), and FPGA also sends CLK_LPC (sysclk_p) to GPIO on KC705 board, and then connect GPIO to the external clk port on the HPC FMC150 board. In this way, HPC board uses the clock from LPC board. So two boards use the same clock.
My questions are: 1. Can SMA GPIO J13 or J14 be connected to the external port of FMC150 board and provide enough driving power/voltage with a clean clock?
2. Can you provide sample code to control CDCE72010 (or anything else) in order to use the external clock? This is important to us since the document doesn't say clearly how to do it. For example, the document says, The onboard VCXO is enabled by default, but can be disabled through the GPIO pins on the AMC7823(see section 5.4). Actually, this is not explained in see section 5.4. I think we still need to do the ADC calibration. Is it right? Please give detailed guidance as much as possible.
3. Do I need to do something on the external trigger?
Also, please let me know If you think this scheme works. If it works, please give me some suggestions on the above questions. If there is a better solution, please let us know. P.S., we are using the reference design provided by Avnet.
1. We don't know, I believe SMA GPIO is an element on the Xilinx board, if so please ask Xilinx what the driver power is! 2. We have a BSP containing a different firmware and a software. The complete chipset is configured by the software via Ethernet link. This BSP should be purchased from us as it is different than what Avnet offer to their customers, you can contact firstname.lastname@example.org to discuss that further 3. Well the CDCE chip and other things should be changed. This is something you can understand by looking at the FMC150 User Manual and Schematics.
Best Regards, Arnaud
about 4 years ago
This topic is being closed because the issue is considered as resolved by 4DSP. Feel free to create a new topic for any further inquiries.