Chapter 26. Detailed Physical Layer Description

The Previous Chapter

The previous chapter provided a detailed description of the Link Layer. This included:

• Link Layer functional overview.

• Link state machine.

• Detailed description of LRH.

• QoS within the subnet: SL and VLs.

• Detailed description of VL arbitration.

• Link-Level Flow Control.

• Packet CRCs.

• Intro to the packet delimiters.

• Packet receive state machine.

• Data packet check.

• Link packet (Flow Control packet) check.

• Switch performs packet forwarding.

• Overview of router port's Link Layer.

This Chapter

This chapter provides a detailed description of the Physical Layer and includes:

• Module basics.

• Port types.

• Signal naming conventions.

• Electrical signaling and copper cable.

• Link Layer to Physical Layer interface.

• Transmit logic functions.

• Receiver logic functions.

• Link training.

• Physical Layer error handling.

• Repeaters.

• Performance counters.

This chapter concludes the part of the book that focuses on the Link and Physical Layers (i.e., Part 5).

The Next Chapter

The next chapter provides a detailed descripion of the Subnet Management Interface (SMI). It includes:

• Purpose of the SMI (QP0).

• The SMI on a CA and a router.

• The SMI on switches.

• Detailed switch handling of SMPs.

• Detailed CA or router handling of SMPs.

• SM accessing an attribute in its local device.

• SM can reside in a switch.

• SMI is a privileged resource.

• SMI only communicates with other SMIs.

• The port states in which SMPs can be sent and received.

• SMPs never leave the subnet.

• Setting up an HCA port's SMI.

• How the SM sends a message and handles a response.

• An SMP's source and destination.

• The SMI and the Q_Key.

• The SMI and partitions.

• Additional reference material.