Forum Discussion
Agilex5: How to use a GTS refclk to clock the FPGA fabric?
- 2 months ago
Hi,
posted minimal design doesn't work because it doesn't connect system PLL output to anything, thus the PLL is discarded during synthesis.
Modified top.sv respectivelyassign {//pad_rled0, pad_gled0, pad_bled0, pad_rled1, pad_gled1, pad_bled1, pad_rled2, pad_gled2, pad_bled2, pad_rled3, pad_gled3, pad_bled3} = 11'o213; //12'o4213; assign pad_dbg_tx = pad_dbg_rx; assign pad_rled0 = clk101p768092; assign clk101p768092_ready = 1'b1;
Connecting the PLL reveals another error. The fact that you never got to this point suggests that the PLL wasn't implemented in your design, e.g. due to missing connectivity.Error(22849): Intel FPGA IP instantiated in the design requires the DEVICE_INITIALIZATION_CLOCK option to be set to either OSC_CLK_1_25MHZ, OSC_CLK_1_100MHZ, or OSC_CLK_1_125MHZ. This assignment is missing in the QSF file.
Added
set_global_assignment -name DEVICE_INITIALIZATION_CLOCK OSC_CLK_1_100MHZ
Get still complains about missing constraints, but design basically compiles now.
Regards
Frank
P.S.: Don't know, if DEVICE_INITIALIZATION_CLOCK is actually required to run system_pll. GTS PHY itself needs it according to device handbook.
Thank you for the feedback. I'm not able to manually enter any frequency in the field, only select from the dialog box as shown below: