MB86967 Datasheet, PDF (17/129 Pages) Fujitsu Component Limited. – LAN Controller with PC Card, ISA Bus, and General-purpose Bus Interfaces

MB86967
s BLOCK DESCRIPTION
The MB86967 has five functional blocks. The functions of each block in the PC card mode, ISA mode, and
general-purpose bus mode is explained below.
1. 10BASE-T Transceiver
The 10BASE-T transceiver pre-distorts transmit packets from the Manchester encoder/decoder to be suitable
for use in the 10BASE-T jitter template. Filtering is performed by an external active filter. The transceiver passes
the received packets through an internal receive filter and transfers them to the encoder/decoder.
2. Manchester Encoder/Decoder
The Manchester encoder/decoder converts NRZ-formatted transmit packets from the data link controller into
Manchester code and transfers them to the 10BASE-T transceiver. The encoder/decoder converters the receive
packets from the transceiver from Manchester code to NRZ format and transfers them to the data link controller.
3. Data Link Controller
The data link controller performs the function of the data link layer specified in the IEEE802.3 standard. At
transmitting, the controller attaches the preamble and CRC code to transmit data from buffer memory and
transmits it as serial data to the Manchester encoder/decoder. In the event of a collision, the controller
automatically executes the back-off algorithm for re-transmission.
At receiving, the data link controller performs address-matching and error checks for receive packets from the
Manchester encoder/decoder, removes the preamble and CRC code from the packets, and converts them to
serial data before writing to buffer memory.
The data link controller has a multicast address filter to recognize up to 64 groups of multicast addresses.
4. Buffer Manager
The MB86967 needs external SRAM (expandable to 32 Kbytes) for buffering transmit and receive data. Buffer
memory is divided into a dual-bank transmit buffer and ring receive buffer where all processing such as arbitration
of access from the system and network and updating of buffer pointers is performed automatically by the buffer
manager. The transmit buffer has a packet chain function for continuously transmitting the packets of data stored
in it using one transmit-start instruction.
5. System Interface
Like the MB86965B and MB86964, the mode pin setting allows the system interface to switch between the
general-purpose interface, ISA bus interface enabling direct interface with the ISA bus, and PC card interface
based on the JEIDA4.2 standard.
When in the ISA bus interface mode, a serial EEPROM can be connected for storing node IDs and two modes
can be selected: a jumperless mode allowing software setting of I/O addresses and interrupt signals for the LAN
controller, and a jumper mode allowing DIP-switch setting.
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