GTS Transceiver PHY User Guide: Agilex™ 3 FPGAs and SoCs
3.7. Clocking
Word Clock
The word clock is a PMA parallel clock and equals the data rate divided by the PMA width. For example: 10.3125 Gbps data rate with 32-bit PMA width has a word clock of 10.3125 Gbps ÷ 32 = 322.265625 MHz.
User Clock
User clock is the divided version of the PMA data rate. The available division factor for user clock is shown below.
The user clock is calculated as the VCO frequency divided by a division factor, which you specify in the TX/RX user clock div by parameter in the TX/RX User clock settings in the parameter editor.
User clock = VCO frequency / Division factor
The valid range of division factors is from 12 to 139.5, in increments of 0.5; for example, 12, 12.5,13,13.5, ……, 139, 139.5.
The TX and RX clocks for the word clock and user clock are two different clocks, derived from TX and RX PMA, respectively.
Sys PLL Clock
The Sys PLL clock is the output clock from system PLL. The frequency of this clock is the same as the output frequency of the system PLL connected to the current instance of the GTS PMA/FEC Direct PHY IP.
Section Content
Clock Ports
Recommended tx/rx_coreclkin Connection and tx/rx_clkout2 Source
Port Widths and Recommended Connections for tx/rx_coreclkin, tx/rx_clkout, and tx/rx_clkout2
PMA Fractional Mode
Input Reference Clock Buffer Protection
Guidelines for Obtaining the Real-Time GTS TX PLL Lock Status