05-30-2019 04:00 AM
Hi all,
I've hit into a bit of an issue when trying to utilise an FPGA + I/O module setup for high speed communication with a device via a mix of LVDS and SE pins. I'm trying to run at a variable clock anywhere between 210 and 40Mhz and when running initial tests I've encountered two problems:
- When running using a derived clock rather than a base Labview will not let you read and write from a bank of pins at the same time, I've been in contact with support and this is a known issue, as such will need a different approach
- Strange compilation issues wherein the reported timing errors do not match the underlying Vivado reports, for example when the initial timing is generated the clock is ~10Mhz below the target (which is the usual as it is highly pessimistic) and after the actual timing report this has decimated itself down, leading to a result anywhere from 10 to 150Mhz below the target
We're now looking into using an external clock and finding a way of bypassing the timing restrictions on the I/O module, has anybody had any experience with this type of issue before?
We're running Labview 2015 SP1 with a 7953R FPGA attached to a 6583 I/O adaptor in a PXIe chassis, with the I/O module in DDR mode to allow for running at over 200Mhz.
Thanks in advance,
Paul
05-31-2019 03:12 AM
Hi Paul,
Are you using Xilinx IP in your compilations?
It might be worth posting on the Xilinx forums too if your seeing disparities in the Vivado Reports. A better idea of what the project you're wishing to compile will also be pretty helpful in trying to find a root cause of the issues you're facing here.
Cheers!
Jacob Hopkins
Technical Support Engineer