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Altera CPRI IP Core User Manual

Page 161

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Appendix B: Implementing CPRI Link Autorate Negotiation

B–5

Autorate Negotiation From 9.8304 Gbps in Arria V GT Variations

December 2013

Altera Corporation

CPRI MegaCore Function

User Guide

Table B–1

lists the frequencies at which you must drive the

usr_clk

and

usr_pma_clk

input clocks in these CPRI IP core variations.

If your CPRI IP core Arria V GT variation is configured with the 9.8304 Gbps CPRI
line rate, it cannot negotiate down to a CPRI line rate of 0.6144 Gbps.

Table B–1. usr_ck and usr_pma_clk Frequencies at Different Target CPRI Line Rates

Target CPRI Line Rate (Gbps)

Frequency (MHz)

usr_clk

usr_pma_clk

9.8304

245.76

122.88

6.144

153.6

76.8

4.9152

122.88

61.44

3.0720

76.8

153.6

2.4576

61.44

122.88

1.2288

30.72

61.44