Zilog EZ80190 - Manual (Page 62)

eZ80190 Development Kit
User Manual
Troubleshooting UM014108-0810
58
IrDA Port Not Working
If you plan on using the IrDA transceiver on the eZ80 Webserver-i E-NET
Module, make sure the hardware is set up as follows:
•
Jumper J2 must be OFF (to enable the control gate that drives the
IrDA device)
•
Set port pin PD2 Low. When this port pin and Jumper J2 are turned
OFF, the IrDA device is enabled.
•
Install a jumper on connector J6 across pin names con_dis and GND
to disable the console serial port driver
Difference Between EMAC and IP Address
Media Access Control (MAC)
Each and every Ethernet device interface to the network media (e.g., net-
work adapter, port on a hub) contains a unique MAC address, which is
hard-coded into the hardware when it is manufactured. An Ethernet
device addresses a host using a unique 48-bit address called its Ethernet
address or Media Access Control (MAC) address.
MAC addresses are usually represented as six colon-separated pairs of
hex digits, e.g., 6:0:20:11:ac: 85. The first three bytes (e.g., 6-0-20) are
the manufacturer’s code, which can be used to identify the manufacturer.
The last three bytes are the unique station ID or serial number for the
interface. This station ID is unique and is associated with a particular
Ethernet device. The Data Link layer's protocol-specific header specifies
the MAC address of the packet's source and destination. When a packet is
sent to all hosts (broadcast), a special MAC address (ff:ff:ff:ff:ff:ff) is
used.
MAC addresses uniquely identify each node in a network at the Media
Access Control layer, the lowest network layer that directly interfaces
with the physical media (e.g., twisted-pair wires).