GTS Transceiver PHY User Guide: Agilex™ 5 FPGAs and SoCs

ID 817660
Date 10/17/2025
Public
Document Table of Contents

5.7. Connecting the Reference Clock Buffer Status to the GTS Reset Sequencer IP

Each non- PCIe* IP has one reference clock buffer failed status port o_refclk_status_bus_out to indicate the status of the reference clock for that side of the device. For multiple IP applications, on the same side of the device, only one port needs to be connected to the GTS Reset Sequencer IP. You can choose which IP is connected GTS Reset Sequencer IP and leave the rest unconnected.

From the GTS Reset Sequencer IP, there are two output ports, o_refclk_fail_status and o_refclk_on_ack, that you must connect to your logic to monitor the status of the reference clock buffer. When o_refclk_fail_status indicates a reference clock buffer is turned off, you can turn the clock buffer back on using i_refclk_on after restoring the clock source. You will receive an acknowledgment signal from the o_refclk_on_ack port. You can then deassert the i_refclk_on port. You can continue to monitor the reference clock buffer status using the o_refclk_fail_status port.

The example connections are shown in the following figure:
Figure 90. Reference Clock Buffer Status Connection
For the input and output ports of the correspondence bits, refer to the following table:
Table 96.  Input and Output Ports of Clock Buffer Bit Information
  i_src_rs_refclk_status_bus_out / i_refclk_on o_refclk_fail_status / o_src_rs_refclk_cmd_bus_in
1D/4D Regional Ref Clock 7 7
Local Ref Clock 6 6
1C/4C Regional Ref Clock 5 5
Local Ref Clock 4 4
1B/4B Regional Ref Clock 3 3
Local Ref Clock 2 2
1A/4A Regional Ref Clock 1 1
Local Ref Clock 0 0