21145
Preliminary
Datasheet
1
1.0
Introduction
This manual contains detailed electrical and mechanical specifications for the 21145 Phoneline/
Ethernet LAN Controller.
1.1
Manual Organization
This manual contains the following.
Section 1.0
, “Introduction”, provides a general description of the 21145 and an overview of the
hardware components.
Section 2.0
“Pinout and Signal Descriptions”, provides the physical layout of the 21145 and
describes each of the input and output signals.
Section 3.0
“Electrical and Environmental Specifications”, describes the 21145’s electrical and
environmental specifications.
Section 4.0
“Mechanical Specifications”, includes the 21145 144-pin and 176-pin package
marking and mechanical specifications.
1.2
General Description
The 21145 is an Ethernet/HomePNA LAN controller for both 100 Mb/s and 10 Mb/s data rates,
that integrates a HomePNA PHY for 1 Mb/s data rate home networking on telephone lines. The
21145 provides a direct interface to the Peripheral Component Interconnect (PCI) local bus or to
the CardBus. The 21145 interfaces to the host processor by using onchip command and status
registers (CSRs) and a shared host memory area, set up mainly during initialization. This
minimizes processor involvement in the 21145 operation during normal reception and
transmission.
The 21145 also incorporates a modem interface, and can operate with a wide range of modem
chipsets available in the marketplace.
The 21145 is optimized for low power PCI/CardBus based systems and supports a power-management
mechanism based upon the OnNow architecture for Microsoft’s
PC 97 Hardware Design Guide,
PC 98 Hardware Design Guide, and PC 99 Hardware Design Guide
.
Large FIFOs allow the 21145 to efficiently operate in systems with longer latency periods. Bus
traffic is also minimized by filtering out received runt frames and by automatically retransmitting
collided frames without a repeated fetch from the host memory. The 21145 provides an upgradable
expansion ROM interface.
The 21145 provides these network interfaces:
10BASE-T 10 Mb/s port
HomePNA port
A media-independent/symbol interface (MII/SYM) 10/100 Mb/s port
The 10BASE-T port provides a direct Ethernet connection to the twisted-pair (TP) interface. The
HomePNA port provides a direct interface to a telephone line at a rate of 1 Mb/s.