PI7C9X111SLBFDE Pericom Semiconductor, PI7C9X111SLBFDE Datasheet - Page 20

• Manufacturer Part Number: PI7C9X111SLBFDE
• Manufacturer: Pericom Semiconductor

Specifications of PI7C9X111SLBFDE

• Lead Free Status / Rohs Status: Compliant

5
5.1
5.2
PCI Express TLP (Transaction Layer Packet) Structure is comprised of format, type, traffic class, attributes, TLP
digest, TLP poison, and length of data payload.
There are four TLP formats defined in PI7C9X111SL based on the states of FMT [1] and FMT [0] as shown on
Table 4-1.
Table 4-1 TLP Format
Data payload of PI7C9X111SL can range from 4 (1DW) to 256 (64DW) bytes. PI7C9X111SL supports three TLP
routing mechanisms. They are comprised of Address, ID, and Implicit routings. Address routing is being used for
Memory and IO requests. ID based (bus, device, function numbers) routing is being used for configuration
requests. Implicit routing is being used for message routing. There are two message groups (baseline and advanced
switching). The baseline message group contains INTx interrupt signaling, power management, error signaling,
locked transaction support, slot power limit support, vendor defined messages, hot-plug signaling. The other is
advanced switching support message group. The advanced switching support message contains data packet and
signal packet messages. Advanced switching is beyond the scope of PI7C9X111SL implementation.
The r [2:0] values of the "type" field will determine the destination of the message to be routed. All baseline
messages must use the default traffic class zero (TC0).
This section provides a summary of Virtual Isochronous Operation supported by PI7C9X111SL. Virtual
Isochronous support is disabled by default. Virtual Isochronous feature can be turned on with setting bit [26] of
offset 40h to one. Control bits are designated for selecting which traffic class (TC1-7) to be used for upstream (PCI
Express-to-PCI). PI7C9X111SL accepts only TC0 packets of configuration, IO, and message packets for
downstream (PCI Express-to-PCI). If configuration, IO and message packets have traffic class other than TC0,
PI7C9X111SL will treat them as malformed packets. PI7C9X111SL maps all downstream memory packets from
PCI Express to PCI transactions regardless the virtual Isochronous operation is enabled or not.
Pericom Semiconductor - Confidential
PCI EXPRESS FUNCTIONAL OVERVIEW
TLP STRUCTURE
VIRTUAL ISOCHRONOUS OPERATION
FMT [1]
0
0
1
1
FMT [0]
0
1
0
1
TLP Format
3 double word, without data
4 double word, without data
3 double word, with data
4 double word, with data
Page 20 of 78
Feb, 2010, Revision 1.5
PCIe-to-PCI Reversible Bridge
PI7C9X111SL