User`s guide

Aironet Wireless Communications, Inc. 7-1 Confidential and Proprietary
7
CHAPTER 7 A
PCMCIA and ISA Client Software Interface
This chapter details the software interface to the PC4500/4800. Refer to chapters 4 and 5 for details
about the PCMCIA and ISA hardware interfaces.
The main software components in a PCMCIA environment are Card Services and Socket Services. The
use of these services provides sufficient abstraction to allow the use of multiple PC cards through
different PCMCIA interface hardware. Socket Services provides actual PCMCIA hardware interface
support and Card Services provides client processes access to the PC cards that are in use. Once a client
registers with card services, it will then be informed of relevant events pertaining to the PC cards
currently installed.
The PC4500/4800 is accessed via 32 contiguous 16-bit I/O registers. Each register is assigned an offset
which relates to the base port address used by the socket. (Base port address plus offset yields the port
address through which each register is accessed.) Since all registers are 16-bit registers, two I/O ports are
used for register access. The hardware will transfer 8 bits via the respective port address and 8 bits via
port address+1. Therefore, an area of 64 continuous I/O ports are required for PC4500/4800 controller
access.
All sample code shown in this chapter uses “PC4500” as a part of variable names and in comments. This
sample code, however, is appropriate for use with the PC4800 as well.
Host Memory Map
The host has two memory spaces available to it: I/O Space and Attribute Memory. Common memory is
not available on the PC4500/4800.