Technical Information
4–11
4.3.4
NI Module Description
The Network Interface (NI) module provides the interface to the IEEE 802.3/Ether-
net network(s). Major components on this module are the NI packet memory, the NI
chipset, and the translation processor. In addition, the NI3 module contains a for-
warding processor.
The NI packet memory stores packets received from and destined to the IEEE
802.3/Ethernet network(s). It also provides a means of communication between the
application processor and the translation processor.
The NI chipset provides the interface between NI packet memory and the physical
interface circuitry. The NI chips perform all IEEE 802.3/Ethernet MAC-level func-
tions, and also provide a direct memory access (DMA) to packet memory.
Because the FDDI and IEEE 802.3/Ethernet networks use different frame formats,
the translation processor modifies the format of packets being forwarded from one
network to the other.
The forwarding processor (in an NI3 module) handles the transfer of packets through
the various queues in NI packet memory. Once the AP determines on what outbound
port(s) a packet will be forwarded, the FP ensures that the packet is placed on the
appropriate queue(s) to accomplish this.
4.3.5
Power Supply
The DECbridge 500/600 series power supply supplies the following outputs:
•
+5.1 V at 50 amps (maximum)
•
+12.0 V at 1.7 amps (maximum)
•
–12.0 V at 1.7 amps (maximum)
•
A separate, isolated 12 V at 1.0 amps (maximum) per fan
