PCI Express® Base Specification Revision 4.0 Version 0.3.pdf.zip

1. INTRODUCTION............................................................................................................... 46 1.1. A THIRD GENERATION I/O INTERCONNECT ................................................................... 46 1.2. PCI EXPRESS LINK......................................................................................................... 49 1.3. PCI EXPRESS FABRIC TOPOLOGY .................................................................................. 50 1.3.1. Root Complex........................................................................................................ 50 1.3.2. Endpoints .............................................................................................................. 51 1.3.3. Switch .................................................................................................................... 54 1.3.4. Root Complex Event Collector .............................................................................. 55 1.3.5. PCI Express to PCI/PCI-X Bridge........................................................................ 55 1.4. PCI EXPRESS FABRIC TOPOLOGY CONFIGURATION ....................................................... 55 1.5. PCI EXPRESS LAYERING OVERVIEW.............................................................................. 56 1.5.1. Transaction Layer ................................................................................................. 57 1.5.2. Data Link Layer .................................................................................................... 57 1.5.3. Physical Layer ...................................................................................................... 58 1.5.4. Layer Functions and Services............................................................................... 58 TRANSACTION LAYER SPECIFICATION ................................................................. 62 2.1. TRANSACTION LAYER OVERVIEW.................................................................................. 62 2.1.1. Address Spaces, Transaction Types, and Usage................................................... 63 2.1.2. Packet Format Overview ...................................................................................... 65 2.2. TRANSACTION LAYER PROTOCOL - PACKET DEFINITION............................................... 67 2.2.1. Common Packet Header Fields ............................................................................ 67 2.2.2. TLPs with Data Payloads - Rules ......................................................................... 70 2.2.3. TLP Digest Rules .................................................................................................. 74 2.2.4. Routing and Addressing Rules .............................................................................. 74 2.2.5. First/Last DW Byte Enables Rules........................................................................ 78 2.2.6. Transaction Descriptor ......................................................................................... 81 2.2.7. Memory, I/O, and Configuration Request Rules................................................... 87 2.2.8. Message Request Rules ......................................................................................... 94 2.2.9. Completion Rules ................................................................................................ 115 2.2.10. TLP Prefix Rules ................................................................................................. 118 2.3. HANDLING OF RECEIVED TLPS.................................................................................... 123 2.3.1. Request Handling Rules...................................................................................... 126 2.3.2. Completion Handling Rules................................................................................ 138 2.4. TRANSACTION ORDERING ............................................................................................ 142 2.4.1. Transaction Ordering Rules ............................................................................... 142 ......