Visible to Intel only — GUID: sam1403478179955
Ixiasoft
Visible to Intel only — GUID: sam1403478179955
Ixiasoft
6.3.2. Transmitter Clocking
The fractional PLL generates the load enable (LVDS_LOAD_EN) signal and the diffioclk signal (the clock running at serial data rate) that clocks the load and shift registers. You can statically set the serialization factor to x3, x4, x5, x6, x7, x8, x9, or x10 using the Quartus® Prime software. The load enable signal is derived from the serialization factor setting.
You can configure any Arria® V transmitter data channel to generate a source-synchronous transmitter clock output. This flexibility allows the placement of the output clock near the data outputs to simplify board layout and reduce clock-to-data skew.
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 Quartus® Prime IP Catalog:
- The transmitter can output a clock signal at the same rate as the data—with a maximum output clock frequency that each speed grade of the device supports.
- You can divide the output clock by a factor of 1, 2, 4, 6, 8, or 10, depending on the serialization factor.
- You can set the phase of the clock in relation to the data using internal PLL option of the ALTLVDS IP core. The fractional PLLs provide additional support for other phase shifts in 45° increments.
The following figure shows the transmitter in clock output mode. In clock output mode, you can use an LVDS channel as a clock output channel.