Inter-Layer Interfaces

Transaction/Data Link Interface

The Transaction to Data Link interface provides:
Byte or multi-byte data to be sent across the Link
• Local TLP-transfer handshake mechanism
• TLP boundary information
Requested power state for the Link
PCI EXPRESS BASE SPECIFICATION, REV. 2.1
The Data Link to Transaction interface provides:
Byte or multi-byte data received from the PCI Express Link
TLP framing information for the received byte
Actual power state for the Link
Link status information

Data Link/Physical Interface

The Data Link to Physical interface provides:
Byte or multi-byte wide data to be sent across the Link
• Data transfer handshake mechanism
• TLP and DLLP boundary information for bytes
Requested power state for the Link
The Physical to Data Link interface provides:
Byte or multi-byte wide data received from the PCI Express Link
TLP and DLLP framing information for data
Indication of errors detected by the Physical Layer
Actual power state for the Link
Connection status information