Specialized PCMCIA host adapter for use with low cost microprocessors

A system comprising:

• a system bus;
• a main memory for storing data coupled to the system bus;
• a central processing unit coupled to the system bus, wherein the central processing unit includes a DMA controller which controls DMA read/write operations to/from the main memory;
• a host adapter logically coupled between the system bus and a set of PCMCIA lines, wherein the host adapter performs a DMA read from the main memory, a DMA write to the main memory, a non-DMA read from the PCMCIA device, and a non-DMA write to the PCMCIA device.

In a system having a microprocessor, a DMA controller, a host adapter, a system bus, a main memory, and non-DMA interface, a method for transferring data from a non-DMA device to the main memory, comprising the steps of:

• generating an interrupt from the device;
• setting up the DMA controller;
• setting up the host adapter;
• loading data from the non-DMA device to the host adapter according to a non direct memory access;
• writing the data from the host adapter to the main memory with a DMA write operation.

In a system having a microprocessor, a DMA controller, a host adapter, a system bus, a main memory, and non-DMA interface, a method for transferring data from the main memory to a non-DMA device, comprising the steps of:

• setting up the host adapter;
• setting up the DMA controller;
• loading the data from the main memory into the host adapter with a DMA operation;
• writing the data from the host adapter to the device in a non-DMA operation.