Fast ethernet interface, Table 3-10, Fast ethernet interface pin signals (j2) – ADLINK CoreModule 435 User Manual
Page 34
Chapter 3
Hardware
28
Reference Manual
CoreModule 435
Fast Ethernet Interface
The Fast Ethernet solution originates from the Vortex 86SX/DX CPU and consists of both the Media Access
Controller (MAC) and the Physical Layer (PHY) combined into a single component solution. The Vortex
Fast Ethernet Control Unit is a 32-bit PCI controller that features enhanced scatter-gather bus mastering
capabilities, which enables the processor to perform high-speed data transfers over the internal PCI bus. The
bus master capabilities enable the component to process high-level commands and perform multiple
operations, thereby off-loading communication tasks from the CPU. The Fast Ethernet interface offers the
following features:
•
Full duplex or half duplex support
•
Full duplex support at 10 Mbps or 100 Mbps
•
In full duplex mode, the Fast Ethernet controller 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 10BaseT/100BaseTX compatible physical layer to wire transformer
•
Two on-board LEDs support the speed and the link & activity status
•
IEEE 802.3u Auto-Negotiation support
•
Fast back-to-back transmission support with minimum interframe spacing (IFS).
•
IEEE 802.3x auto-negotiation support for speed and duplex operation
•
3 kB transmit and 3 kB receive FIFOs (helps prevent data underflow and overflow)
•
IEEE 802.3x 100BaseTX flow control support
•
On-board magnetics (Ethernet isolation transformer)
describes the pin signals of the Fast Ethernet interface, which uses a single-row, 8-pin header
with 0.100" (2.54mm) pitch.
Table 3-10. Fast Ethernet Interface Pin Signals (J2)
Pin # Signal
Description
1
TX+
Analog Twisted Pair Ethernet Transmit Differential Pair – These pins transmit the
serial bit stream through the isolation transformer.
2
TX-
3
RX+
Analog Twisted Pair Ethernet Receive Differential Pair – These pins receive the
serial bit stream through the isolation transformer.
6
RX-
4
CT
Center Tap – Connected through two 75 ohm resistors in series to center tap of
isolation transformer and then to ground through common 1k PF capacitor.
5
CT
7
CT
Center Tap – Connected through two 75 ohm resistors in series to center tap of
isolation transformer and then to ground through common 1k PF capacitor.
8
CT
NOTE
The magnetics (isolation transformer, U12) for the Ethernet connector is
included on the CoreModule 435.