SMSC LAN1198 Manual De Usuario

LAN9118 Family Programmer Reference Guide

Revision 1.0 (12-14-09)

2

SMSC AN 12.12

 

„

An octet or byte is a group of 8 bits, treated as a single unit, with a value of 0-255 unsigned, or -
127 to +127 signed. A byte is generally the smallest unit of data that can be individually addressed.

„

A word or short int is a group of 16 bits or two bytes,2 adjacent bytes, representing a 16-bit, single 
symbol or a numeric range from 0 – 65,535 unsigned, or +/- 32,767 as a signed value.  WORD 
values are aligned on 2-byte memory boundaries.  Their addresses are always expressed in even 
number terms ending in 0x0, 0x2, 0x4, 0x6, 0x8, 0xa, 0xc, and 0xe.

„

A DWORD or long int always refers to 4 adjacent bytes, representing a 32-bit, single symbol or a 
numeric range from 0 – 4,294,967,295, or +/- 2,147,483,647 as a signed value.  DWORD values 
are aligned on 4-byte memory boundaries.  Their addresses are always expressed in even number 
terms ending in 0x0, 0x4, 0x8, and 0xc.

LAN9118 Family devices are full-featured, single-chip 10/100 Ethernet controllers designed for
embedded applications where performance, flexibility, ease of integration and low cost are required.
LAN9118 Family devices are fully IEEE 802.3 10BASE-T and 802.3u 100BASE-TX compliant.

LAN9118 Family devices include an integrated Ethernet MAC and PHY with a high-performance
SRAM-like slave interface. The simple, yet highly functional host bus interface provides glue-less
connection to most common 32- and 16-bit microprocessors and microcontrollers, including those 32-
bit microprocessors presenting a 16-bit data bus interface to the device. LAN9118 Family Devices
include large transmit and receive data FIFOs with a high-speed host bus interface to accommodate
high bandwidth, high latency applications. In addition, the devices memory buffer architecture allows
the most efficient use of memory resources by optimizing packet granularity.