IP-CPRI Altera, IP-CPRI Datasheet - Page 37

• Manufacturer Part Number: IP-CPRI
• Description: IP CORE - Common Public Radio Interface (CPRI)
• Manufacturer: Altera

Specifications of IP-CPRI

• Software Application: IP CORE, Interface And Protocols, HIGH SPEED
• Supported Families: Arria II GX, Cyclone IV GX, HardCopy IV, Stratix IV
• Core Architecture: FPGA
• Core Sub-architecture: Arria, Cyclone, Stratix
• Rohs Compliant: NA
• Lead Free Status / RoHS Status: na
• Lead Free Status / RoHS Status: na

Chapter 4: Functional Description
Clocking and Reset Structure
Table 4–1. CPRI Link Line Rates and Clock Rates for CPRI MegaCore Function (Part 2 of 2)
December 2010 Altera Corporation
Note to
(1) The CPRI MegaCore function supports CPRI line rates 4915.2 Mbps and 6144 Mbps in variations that target Arria II GX devices only for speed
Line Rate
(Mbps)
2457.6
4915.2
3072
6144
grade I3 devices.
Table
MegaCore Function Reset Process
4–1:
Stratix IV GX
In Arria II GZ
Devices
122.88
153.60
61.44
76.80
and
The cpri_clkout frequency depends only on the CPRI line rate. The pll_clkout
frequency depends on the CPRI line rate and on the datapath width through the
transceiver. The datapath width is determined by device family, and is shown in
Figure 4–2
The clock gxb_refclk is the incoming reference clock for the device transceiver’s PLL.
When you generate a CPRI MegaCore function variation, you generate an ALTGX
megafunction with specific default settings. These default transceiver settings
configure a transceiver that works correctly with the CPRI MegaCore function when
the input gxb_refclk clock has the frequency shown in
edit the ALTGX megafunction instance to specify a different gxb_refclk frequency
that is more convenient for your design, for example, to enable you to use an existing
clock in your system as the gxb_refclk reference clock.
Altera allows you to program the transceiver to work with any of a set of gxb_refclk
frequencies that the PLL in the transceiver can convert to the required internal clock
speed for the CPRI MegaCore function line rate. The ALTGX parameter editor lets
you select one of the supported frequencies.
The CPRI MegaCore function has multiple independent reset signals. To reset the
CPRI MegaCore function completely, you must assert all the reset signals.
Default gxb_refclk Frequency
In Arria II GX Devices
through
245.76
307.20
122.88
153.60
(1)
(1)
Figure
4–7.
In Cyclone IV GX
Clock Frequency (MHz)
Devices
122.88
153.60
—
—
is supported)
cpri_clkout
(If line rate
Frequency
122.88
153.60
61.44
76.80
Table
Cyclone IV GX
In Arria II GX
CPRI MegaCore Function User Guide
(If line rate is supported)
Devices
4–1. However, you can
122.88
153.60
245.76
307.20
pll_clkout Frequency
and
Stratix IV GX
In Arria II GZ
Devices
122.88
153.60
61.44
76.80
and
4–13