| Popis: |
This chapter focuses on the requirements for a PCMCIA host, implementation of the bridge hardware and its application in support of PC Cards. It covers both CardBus and the 16-bit PC Card interface. There are many issues in PC Card host platform design. The host has to provide full PC Card capability in hardware, operating system-specific drivers, and read-only memory (ROM)-based interface services in software. A PC Card host must provide a hardware bridge to convert from the host bus to PCMCIA, a software abstraction layer, and a generic enabler to configure the host adapter and the PC Card. The function of a bus bridge is to generate address, data, and control signals for a secondary bus from the host bus. If the address space of the host and the second bus are different, the bridge must also provide an address-mapping mechanism. Memory can be mapped to the host address space in two ways—window based or indirect register-based access. |
