User`s manual

Am186™CC Microcontroller Router Reference Design User’s Manual
2-15
10BaseT Ethernet Interface
NOTE: See sheet 4 in the schematics for the Ethernet SRAM packet buffer circuitry
and sheet 3 for the Ethernet controller circuitry.
The Am186CC microcontroller router reference design uses an AMD
Am79C961A PCnet-ISA II Ethernet controller configured in bus master mode for
its Ethernet interface. The Ethernet interface consists of a connection between the
PCnet-ISA II twisted pair interface to an RJ-45 connector, a 20-MHz crystal, an
optional EEPROM for Plug-n-Play (PnP) capability, three status LEDs, SRAM
used to transfer Ethernet packet data, and a small amount of glue logic required to
interface the Am186CC microcontroller to the PCnet-ISA II Ethernet controller.
The Am186CC microcontroller router reference design provides Ethernet through
the PCnet-ISA II twisted pair interface with the addition of a single 10BaseT
transformer (U4 at location L-2) to the RJ-45 connector (P1 at location L-1). To
link the Ethernet station to a network, connect the straight-through cable provided
in your kit to a hub that sits on the network.
Figure 2-4, below, and Table 2-7 on page 2-16 show the pin assignment and pin
functions for the RJ-45 connector.
Figure 2-4. Front View of the RJ-45 Connector
RX-
NC
NC
NC
NC
TX+
TX-
RX+
1234 5678
ch2.fm Page 15 Thursday, July 22, 1999 11:44 AM