Research And Implementation Of PCMCIA Port In Embedded System

In recent years, the embedded processor is widely used in the areas of communication, aviation, mechanical, consumption and so on. The peripherals of the embedded processor change day by day also. The embedded system is generally composed of microprocessor, peripheral hardware, embedded operation system and user applications. Among these four parts, the peripheral supplies abundant ports for function expansion. PCMCIA, which is one of the peripheral ports, supplies wide area for the expansion of the embedded system. The GPRS and wireless PCMCIA cards are widely used on the laptop and PDA. The CF storage card that is inherited from the PCMCIA standard but with smaller cubage also shares a great market in the consumption electronic area. The article first introduces the features of the PCMCIA port and discusses about the Memory and IO working mode of the port. After introducing several other ports used in the embedded system and compares them with the PCMCIA, it draws the conclusion that the PCMCIA port has more advantages. Then it brings forward the two application manners that are standard Host application and the usage as inner bus. In the following sections, it makes detail designs of application of 16bit PCMCIA port based on the two manners each. CF ATA card as the representation of the standard Host application, it discusses of the software architecture of the driver part in Linux and analyses the metaformat of the ATA card. Dual PCMCIA Ethernet expansion as the inner bus application, it analyzes the working mechanism of the interface, the key problem of the realization and simplifies the system architecture within a certain degree. The last chapter does the summarization. Looking forward, doing further research on 32bit PCMCIA port in embedded system will be more promising.