AT79C1030 Datasheet, PDF (1/5 Pages) ATMEL Corporation – 8-Port Gigabit Ethernet CoS Switch

Features
• 8-port 10/100/1000Mb/s Ethernet MII/GMII Switch
• Provides Packet Switching Functions Between 8 Ethernet Ports
• Advanced CoS (Class of Service) Supports 4-level Priority Switching
• Duplex Mode Auto-negotiation Supported
• Full-duplex Flow Control (802.3x) and Half-duplex Back Pressure
• VLAN 802.1Q or Port-based Supported (Port-based, MAC-based
and Protocol Based)
• ARP/Broadcast Filter (Optional)
• 8 GbE Ports with Non-blocking Switching Performance
• Supports Automatic Address Learning and Aging
• Integrated MAC and VLAN Address Tables
• On-chip Packet Buffer Supports Store-and-Forward Switching Architecture
• SPI (RS-232 Interface) for Setup and Unmanaged Operation
• Multicast and Broadcast Storm Control
• Up to 36-Kbyte Media Access Control (MAC) Address Cache
• 1.8V and 3.3V Supply
Description
The AT79C1030 device combines all the functions of a high-speed switch, including
packet buffer, Media Access Controllers (MAC), address management, and a non-
blocking switch fabric. It complies with IEEE 802 specification, providing compatibility
with all industry standard Ethernet, Fast Ethernet, and Gigabit Ethernet devices.
The AT79C1030 utilizes the Store and Forward switching architecture to manage
packet switching between the eight independent Ethernet ports. The switch records
(learning), the relation between MAC addresses (including VLAN information) and the
actual ports. Next, the switch will resolve (forwarding) the destination MAC address of
the ingress packet, then it selects the related ports to transmit the packet. The device
is utilizing and maintaining a MAC address table and a VLAN table to accomplish this
task.
Using Store and Forward, the device reads the whole incoming frame into an internal
on-chip buffer and calculates its own frame check sequence. The switch then com-
pares its CRC figure to the frame's CRC. If the two CRCs are the same, the switch will
consult its address look-up table, create the virtual link and then forward the frame.
The Switch Core uses the packet head information to perform packet filter, packet
drop, address table look up, priority category, etc. After the device completes the task
of forwarding decision, then all the forwarding information will be sent to the forwarding
module.
Each port has an independent forwarding module. The module puts the forwarding
information of the packets forwarded to each respected port. This information
includes:
1. The packet buffer location
2. The size of the packet
3. VLAN information
Four level priority queues are employed at each port. The transmission module
fetches the forwarding information from these different priority queues according to the
round robin rule and transmits the related packet. The higher priority level queues are
more likely to send the packets recorded in it and are less likely to discard these pack-
ets. After resolving each ingress packet, the switch engine can use the obtained
information to perform protocol processing. The device supports VLAN mode switch,
which means only ports belonging to the same VLAN can switch packets. This device
8-Port Gigabit
Ethernet CoS
Switch
AT79C1030
Summary
3435BS–NETST–6/04
Note: This is a summary document. A complete document
is available under NDA. For more information, please con-
tact your local Atmel sales office.