The DM9081 is a 10BASE-T Hub Controller that provides a system level solution for designing IEEE-compliant 802.3 repeaters that incorporate 10BASE-T transceivers. This device integrates the repeater functions specified by section 9 of the IEEE 802.3 standard. The Twisted Pair transceiver is compliant with 10BASE-T standards. The DM9081 provides eight integral Twisted Pair Media Attachment Units (MAUs) and two Attachment Unit Interface (AUI) ports in a 100-pin QFP package. The total number of ports per repeater unit can be increased by connecting multiple DM9081 chips via their expansion ports. The DM9081 supports LED drivers to monitor port status. It displays Link, Carrier Sense, Collision, Partition, and Bit Rate Error Status. In minimum mode, Link, Carrier Sense, and Collision Status can be displayed without external TTL devices.
The DM9081 is a single‑chip IEEE 802.3 Ethernet repeater that integrates eight 10BASE‑T ports and two AUI ports in a 100‑pin QFP package. It offers built‑in LED drivers for link, carrier sense, collision, partition, and bit‑rate error status, and can be expanded by connecting multiple chips via the expansion ports.
Key features include low‑power CMOS technology with a single 5 V supply, automatic collision detection, auto‑partition/reconnection, jabber lockup protection, and a link‑integrity test function. The document details pin assignments, functional blocks, external logic requirements, and mechanical package dimensions.
| Number of 10BASE‑T ports | 8 |
|---|---|
| Package type | 100‑pin QFP |
| Supply voltage | 5 V |
| Jabber protection | MAU Jabber Lockup Protection (MJLP) |
The DM9081 provides eight integral 10BASE‑T ports.
It uses a built‑in jabber lockup protection scheme that stops transmission after 65,536‑bit times of continuous data.