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June 2012
Altera Corporation
Stratix V Hard IP for PCI Express
5. IP Core Architecture
This chapter describes the architecture of the Stratix V Hard IP for PCI Express. The
Stratix V Hard IP for PCI Express implements the complete PCI Express protocol
stack as defined in the
PCI Express Base Specification 3.0.
the following layers:
■
Transaction Layer
—The Transaction Layer contains the Configuration Space, which
manages communication with the Application Layer, the RX and TX channels, the
RX buffer, and flow control credits.
■
Data Link Layer
—The Data Link Layer, located between the Physical Layer and the
Transaction Layer, manages packet transmission and maintains data integrity at
the link level. Specifically, the Data Link Layer performs the following tasks:
■
Manages transmission and reception of Data Link Layer Packets (DLLPs)
■
Generates all transmission cyclical redundancy code (CRC) values and checks
all CRCs during reception
■
Manages the retry buffer and retry mechanism according to received
ACK/NAK Data Link Layer packets
■
Initializes the flow control mechanism for DLLPs and routes flow control
credits to and from the Transaction Layer
■
Physical Layer
—The Physical Layer initializes the speed, lane numbering, and lane
width of the PCI Express link according to packets received from the link and
directives received from higher layers.
provides a high-level block diagram of the Stratix V Hard IP for PCI
Express.
Figure 5–1. Stratix V Hard IP for PCI Express with Avalon-ST Interface
Clock
Domain
Crossing
(CDC)
Data
Link
Layer
(DLL)
Transaction Layer (TL)
PHYMAC
Stratix V Hard IP for PCI Express
Avalon-ST TX
Avalon-ST RX
Side Band
Local
Management
Interface (LMI)
&
Reconfiguration
PIPE
Application
Layer
Clock & Reset
Selection
Configuration
Block
Configuration
Space
PCS
PMA
Physical Layer
(Transceivers)
Configuration via PCIe Link
RX Buffer
PHY IP Core for
PCI Express (PIPE)
June 2012
<edit Part Number variable in chapter>