Signal Tap does not see differential signal REFCLK
Hi all,
I am working with SOM board with Arria 10 SX on it.
Signal Tap does not see differential clock signal from external freq generator. In the same time I see frequencies on external generator output pins (by oscilloscope).
Quartus 18.1 Pro. Compilation of project is finished successfully.
External clock generator (SI5338) prepares 2 frequencies: 125 MHz and 322.26 MHz as differential signals.
These signals connected to U24/U23 (REFCLK_GXBL1C_CHT_P) and W24/W23 (REFCLK_GXBL1C_CHB_P) pins.
I added some assignments in Assignment Editor regarding these signals (see attachment).
But FPGA project does not receive these signals.
I coded simple counter and instantiate it on each of frequencies: 100 MHz (USER_CLK from HPS), 125 MHz (from ext generator) and 322 MHz (from ext generator).
I see signal on output of counter (out signal pulse_out) on 100 MHz only. On the outputs pulse_out of 125 MHz and 322 MHz counters there is nothing.
*.sdc file includes:
# 125MHz for REFCLK_GXBL1C_CHT_P
create_clock -name CLK_125M -period 8 [get_ports REFCLK_GXBL1C_CHT_P]
# 322MHz for REFCLK_GXBL1C_CHB_P
create_clock -name CLK_322M -period 3.103 [get_ports REFCLK_GXBL1C_CHB_P]
Could you help me to understand what is the reason of this problem and what need to change to get right working FPGA?
Thank you in advance.
Dmitry