Features - Freescale Semiconductor MPC850 User Manual

27.2 Features

The following list summarizes the main features of the SCC in Ethernet mode:
• Performs MAC layer functions of Ethernet and IEEE 802.3
• Performs framing functions
— Preamble generation and stripping
— Destination address checking
— CRC generation and checking
— Automatically pads short frames on transmit
— Framing error (dribbling bits) handling
• Full collision support
— Enforces the collision (jamming)
— Truncated binary exponential backoff algorithm for random wait
— Two nonaggressive backoff modes
— Automatic frame retransmission (until the retry limit is reached)
— Automatic discard of incoming collided frames
— Delay transmission of new frames for specified interframe gap
• Maximum 10 Mbps bit rate
• Optional full-duplex support
• Back-to-back frame reception
• Detection of receive frames that are too long
• Multibuffer data structure
• Supports 48-bit addresses in three modes
— Physical–One 48-bit address recognized or 64-bin hash table for physical
addresses
— Logical–64-bin group address hash table plus broadcast address checking
— Promiscuous–Receives all addresses
• Up to eight parallel I/O pins can be sampled and appended to any frame
• Optional heartbeat indication
• Transmitter network management and diagnostics
— Lost carrier sense
— Underrun
— Number of collisions exceeded the maximum allowed
— Number of retries per frame
— Deferred frame indication
— Late collision
• Receiver network management and diagnostics
— CRC error indication
Chapter 27. SCC Ethernet Mode
Features