RapidIO Intel FPGA IP User Guide

ID 683884
Date 9/15/2021
Public
Document Table of Contents

4.2.1.5. Baud Rates and Clock Frequencies

The RapidIO specification specifies baud rates of 1.25, 2.5, 3.125, and 5.0 Gbaud.
Table 16.  Clock Frequencies for 1x and 2x RapidIO IP Core Variations
Baud Rate

(Gbaud)

rxgxbclk (MHz) txclk, rxclk

(MHz)

Avalon® system clock (sysclk)
1x 2x Minimum (MHz) Typical

(MHz)

Maximum

(MHz) 19

1.25 62.5 31.25 31.25 15.625 31.25 46.875
2.5 125 62.5 62.5 31.25 62.5 93.75
3.125 156.25 78.125 78.125 39.065 78.125 117.19
5.0 25020 125 125 62.50 125 187.50
Table 17.  Clock Frequencies for 4x RapidIO IP Core Variations
Baud Rate

(Gbaud)

rxgxbclk (MHz) Avalon® System Clock (sysclk)
Minimum (MHz) Typical

(MHz)

Maximum

(MHz)19

1.25 62.5 31.25 62.5 93.75
2.5 125 62.5 125 187.5
3.125 156.25 78.125 156.25 234.275
5.0 250 125 250 250
Note: The default reference clock frequency is 125 MHz across all device variations. You can select different reference clock frequencies from the set of allowed reference clock frequencies.

The reference clock is called clk.

19 The maximum system clock frequency might be limited by the achievable fMAX and can vary based on the family and speed grade.
20 For Arria® V and Cyclone® V device variations, the rxgxbclk frequency in RapidIO IP core 1x variations at 5 GBaud, is 125 MHz.