Ampro Corporation 5001692A manual Ethernet Interface J2, Tx+, Rx+

Chapter 3 Hardware

Ethernet Interface (J2)

The Ethernet solution is provided by the Intel 82551ER 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 internal 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. The Ethernet interface offers the following features:

•Full duplex or half-duplex support

•Full duplex support at 10Mbps or 100Mbps

•In full duplex mode the 82551ER adheres to the IEEE 802.3x Flow Control specification.

•In half-duplex mode, performance is enhanced by a proprietary collision reduction mechanism.

•IEEE 802.3 10/100BaseT compatible physical layer to wire transformer

•Two on board LEDs support the speed and the link and activity status

•10BaseT auto-polarity correction

•Data transmission with minimum interframe spacing (IFS).

•IEEE 802.3x auto-negotiation support for speed and duplex operation

•3kB transmit and 3kB receive FIFOs (helps prevent data underflow and overflow)

•IEEE 802.3x 100BaseTX flow control support

Table 3-16 describes the pin-outs of the Ethernet connector J2.

Table 3-16. Ethernet Interface Pin/Signal Descriptions (J2)

Pin #	Signal	Description
1	TX+	Analog Twisted Pair Ethernet Transmit Differential Pair – These pins transmit the
		serial bit stream through the isolation transformer on the Unshielded Twisted Pair
2	TX-
		Cable (UTP).
3	RX+	Analog Twisted Pair Ethernet Receive Differential Pair – These pins receive the
		serial bit stream through the isolation transformer.
6	RX-
4	NU	Not Used (RJ45 termination)
5	NU	Not Used (RJ45 termination)
7	NU	Not Used (RJ45 termination)
8	NU	Not Used (RJ45 termination)

Note: NU = Not Used.

CoreModule 420 Reference Manual 37