Arria® V Device Handbook: Volume 2: Transceivers

ID 683573
Date 5/29/2020
Public
Document Table of Contents

2.3.2. Transmitter Datapath Interface Clocking

In 6-Gbps transceivers, the write side of the transmitter phase compensation FIFO makes up the transmitter datapath interface.

For the 6-Gbps transceivers, the write side of the transmitter phase compensation FIFO makes up the transmitter datapath interface. This interface is clocked with the transmitter datapath interface clock.

The following figure shows the 6-Gbps transmitter datapath interface clocking. The transmitter PCS forwards the following clocks to the FPGA fabric:

  • tx_clkout—for each transmitter channel in a non-bonded configuration
  • tx_clkout[0]—for all transmitter channels in a bonded configuration
Figure 71. Transmitter Datapath Interface Clocking for 6-Gbps Transceivers


All configurations that use the PCS channel must have a 0 parts per million (ppm) difference between write and read clocks of the transmitter phase compensation FIFO.

For the 10-Gbps transceivers Arria V GT/ST devices, there are no PCS blocks. The only transmit datapath available is a direct connection from the FPGA fabric to the serializer of the transmitter PMA.

The following figure shows the 10-Gbps transmitter datapath interface clocking. For each transmitter channel in a non-bonded configuration, the FPGA fabric forwards the following tx_clkout clock to the transmitter PMA.

Figure 72. Transmitter Datapath Interface Clocking for 10-Gbps Transceivers (for Arria V GT/ST Devices)


You can clock the transmitter datapath interface by one of the following options:

  • The Quartus II-selected transmitter datapath interface clock
  • The user-selected transmitter datapath interface clock
Note: To reduce GCLK, RCLK, and PCLK resource utilization in your design, you can select the user-selection option to share the transceiver datapath interface clocks.