Altera IP Compiler for PCI Express - Manual (Page 165)

August 2014 Altera Corporation IP Compiler for PCI Express User Guide
7. Reset and Clocks
This chapter covers the functional aspects of the reset and clock circuitry for IP
Compiler for PCI Express variations created using the IP Catalog and parameter
editor. It includes the following sections:
■ Reset Hard IP Implementation
■ Reset Soft IP Implementation
■ Clocks
For descriptions of the available reset and clock signals refer to the following sections
in the
Chapter 5, IP Core Interfaces : “Reset and Link Training Signals” on page 5–24 ,
“Clock Signals—Hard IP Implementation” on page 5–23 , and “Clock Signals—Soft IP
Implementation” on page 5–23 .
Reset Hard IP Implementation
Altera provides two options for reset circuitry in the parameter editor for PCI Express
hard IP implementation. Both options are created automatically when you generate
your IP core. These options are implemented by following files:
■ _plus.v or .vhd—The variant includes the logic for reset and transceiver
calibration as part of the IP core, simplifying system development at the expense
of some flexibility. This file is stored in the /chaining_dma/ directory.
■ .v or .vhd—This file does not include reset or calibration logic, giving
you the flexibility to design circuits that meet your requirements. If you select this
method, you can share the channels and reset logic in a single quad with other
protocols, which is not possible with _plus option. However, you may find it
challenging to design a reliable solution. This file is stored in the
directory.
The reset logic for both of these variants is illustrated by Figure 7–1 .
1 When you use Qsys to generate the IP Compiler for PCI Express, the reset and
calibration logic is included in the IP core variant.
_plus.v or .vhd
This option partitions the reset logic between the following two plain text files:
■ /ip_compiler_for_pci_express-library/altpcie_rs_serdes.v or
.vhd
—This file includes the logic to reset the transceiver.
■ /_examples/chaining_dma/_rs_hip.v or
.vhd
—This file includes the logic to reset the IP Compiler for PCI Express.
The _plus variant includes all of the logic necessary to initialize the IP Compiler for
PCI Express, including the following logic:
■ Reset circuitry
■ ALTGXB Reconfiguration IP core
August 2014