Specifications

Chapter 3 Hardware
44 Reference Manual ReadyBoard 800
10/100BaseT Ethernet Controller
Ethernet Port 1 uses an Intel 82551ER Fast Ethernet, 32-bit PCI controller chip and consists of both
the Media Access Controller (MAC) and the physical layer (PHY) combined into a single component
solution. The 82551ER is a 32-bit PCI controller that features enhanced scatter-gather bus mastering
capabilities, which enables the 82551ER to perform high-speed data transfers over the PCI bus. The
82551ER bus master capabilities enable the component to process high-level commands and perform
multiple operations, thereby off-loading communication tasks from the system CPU.
• Backward software compatible to the 8255x family
• Chained memory structure
• Full duplex or half-duplex support
• Full duplex support at 10 Mbps and 100 Mbps
• In half-duplex mode, performance is enhanced by a proprietary collision reduction mechanism.
• IEEE 802.3 10BaseT/100BaseT compatible physical layer to wire transformer
• Provides two LEDs for speed and link & activity status
• Data transmission with minimum interframe spacing (IFS).
• IEEE 802.3u Auto-Negotiation support
• 3 kB transmit and 3 kB receive FIFOs (helps prevent data underflow and overflow)
• IEEE 802.3x auto-negotiation support for speed and duplex operation
• IEEE 802.3x 100BASE-TX flow control support
• Improved dynamic transmit chaining with multiple priorities transmit queue
• Supports a RJ-45 connector with magnetics integrated into the RJ-45 connector.
Tables 3-14 describes the pin-outs and signals of standard Ethernet port, Ethernet Port 1.
Table 3-14. Ethernet Port 1 Pin/Signal Descriptions (J16)
Pin # Signal Description
1TX2+
2TX2-
Analog Twisted Pair Ethernet Transmit Differential Pair. These pins transmit
the serial bit stream for transmission. These signals interface directly with an
isolation transformer.
3RX2+
6RX2-
Analog Twisted Pair Ethernet Receive Differential Pair. These pins receive
the serial bit stream from the isolation transformer.
4, 5,
7, 8
CT GND
Center Tap Ground – Center taps tied to ground through 75 ohm resistor and
1 nF capacitor.
9 ACT Link/Activity signal indicates a Link is established or Activity is occurring
11 SPEED Speed signal for 10BaseT or 100BaseT transfer rate
10, 12 +VCC LED Power – The +3.3 volts for plus side of both LEDs.
Note: The shaded area denotes power or ground.