User manual

SCC Ethernet Mode
MPC8260 PowerQUICC II Family Reference Manual, Rev. 2
Freescale Semiconductor 25-3
— Two nonaggressive backoff modes
— Automatic frame retransmission (until the attempt 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, but discards frame if REJECT is asserted
• External content-addressable memory (CAM) support on serial bus interfaces
• 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
— Nonoctet alignment error
— Frame too short
— Frame too long
— Overrun
— Busy (out of buffers)
• Error counters
— Discarded frames (out of buffers or overrun occurred)
— CRC errors
— Alignment errors
• Internal and external loopback mode