Agilex™ 7 LVDS SERDES User Guide: M-Series

ID 768615
Date 7/23/2024
Public
Document Table of Contents

3.3. Clocking the Differential Transmitters

The I/O PLL generates the fast_clock signal. The fast_clock signal clocks the load enable and shift registers, and runs at the serial data rate.

You can configure any M-Series LVDS SERDES transmitter data channel to generate a source-synchronous transmitter clock output. This allows placement of the output clock near the data outputs to simplify board layout and reduce clock-to-data skew.

Figure 6. Transmitter in Clock Output


Different applications often require specific clock-to-data alignments or specific data-rate-to-clock-rate factors. You can specify these settings statically in the LVDS SERDES Intel® FPGA IP parameter editor:

  • The transmitter can output a clock signal at the same rate as the data with a maximum output clock frequency supported by the device speed grade.
  • You can divide the output clock by a factor of 4 or 8, depending on the serialization factor.
  • You can set the phase of the clock in relation to the data at 0° (edge-aligned) or 180° (center-aligned). The I/O PLLs provide additional support for other phase shifts in 45° increments.