Transaction Layer Routing Rules - Altera Cyclone V User Manual

Chapter 8: Transaction Layer Protocol (TLP) Details

Transaction Layer Routing Rules

Table 8–1. Supported Message Types
Root
Message
Port
Attention_indicator On Transmit
Attention_Indicator
Transmit
Blink
Attention_indicator_
Transmit
Off
Power_Indicator On Transmit
Power_Indicator Blink Transmit
Power_Indicator Off Transmit
Attention
Receive
(1)
Button_Pressed
Notes to Table 8–1:
(1) In Endpoint mode.
(2) In the PCI Express Base Specification Revision
Transaction Layer Routing Rules
Transactions adhere to the following routing rules:
■ In the receive direction (from the PCI Express link), memory and I/O requests that
match the defined base address register (BAR) contents and vendor-defined
messages with or without data route to the receive interface. The Application
Layer logic processes the requests and generates the read completions, if needed.
■ In Endpoint mode, received Type 0 Configuration requests from the PCI Express
upstream port route to the internal Configuration Space and the Cyclone V Hard
IP for PCI Express generates and transmits the completion.
■ The Hard IP handles supported received message transactions (Power
Management and Slot Power Limit) internally. The Endpoint also supports the
Unlock and Type 1 Messages. The Root Port supports Interrupt, Type 1 and error
Messages.
■ Vendor-defined Type 0 Message TLPs are passed to the Application Layer.
■ The Transaction Layer treats all other received transactions (including memory or
I/O requests that do not match a defined BAR) as Unsupported Requests. The
Transaction Layer sets the appropriate error bits and transmits a completion, if
needed. These Unsupported Requests are not made visible to the Application
Layer; the header and data is dropped.
November 2011 Altera Corporation
(2)
(Part 3 of 3)
Generated by
Endpoint
App
Layer
Hot Plug Messages
Receive No
Receive No
Receive No
Receive No
Receive No
Receive No
Transmit No
2.1, this message is no longer mandatory after link training.
Core (with
Core App Layer
input)
Yes No
Yes No
As per the recommendations in the
Express Base Specification Revision 2.1
Yes No these messages are not transmitted to the
Application Layer.
Yes No
Yes No
Yes No
No Yes
8–3
Comments
PCI
,
Cyclone V Hard IP for PCI Express
User Guide