User`s guide

Aironet Wireless Communications, Inc. 6-1 Confidential and Proprietary
6
CHAPTER 6 A
Serial Hardware Interface Operation
This chapter details the hardware aspects of the PC4500/4800 Serial host interface. See chapter 8 for
details about the available software interfaces.
Serial Hardware
The PC4500/4800 PC card offers a Serial Interface mode to the host device by re-mapping the upper
PCMCIA address lines to a UART-type serial interface. This allows the PC4500/4800 to be embedded
and interfaced to via a serial port. The serial interface can be accessed using a serial protocol referred to
as PLAP.
Serial Mode
The Serial mode is invoked automatically by the PC4500/4800 PC card upon a read of the VPP lines as
listed in Table 6-2, and the reception of the autobaud sequence.
A power-on reset signal is provided internally. No external reset signal is required. The standard
PCMCIA Card Reset signal (pin 58) is still available, being wire OR’d with the internal reset. This
arrangement is present in both PCMCIA and Serial modes. Typical Serial mode applications require pin
58 to be driven low.
Table 6-1 lists the operating parameters of the PC4500/4800 Serial Mode interface.