Abstract: A PCMCIA host adapter includes the capability to master a non-DMA system bus and control a DMA data transfer between a DMA capable peripheral and the internal system memory. A peripheral can be coupled to the system through a PCMCIA card plugged into a PCMCIA expansion slot. A DMA controller coupled to the PCMCIA expansion slots through a PCMCIA bus controls a DMA transfer between the internal system memory and the peripheral. A bus master disables the CPU and takes control of the system bus during a DMA data transfer. In an alternative embodiment, the PCMCIA host adapter can be used with either a system having a system bus with DMA capability or with a system having a system bus without DMA capability. In this alternate embodiment if the system bus has DMA capability, the PCMCIA host adapter effectively passes the DMA signals between the peripheral and the system bus.

Abstract: A high performance Local Bus Peripheral Interface (LBPI) for a computer local bus and high performance peripheral interface(s) uses a pipelined architecture to increase use of available data transfer bandwidth. The LBPI coupled between the computer local bus and peripheral interface(s) is provided a pipelined architecture including a Read Ahead Buffer, a Read Ahead Counter, a Data Out Latch, and a controlling State Machine with a Configuration Register. The LBPI supports DMA and PIO data transfers on the peripheral side. In another embodiment, the LBPI translates memory data transfers into IO data transfers to improve efficiency of IO data transfers. A DMA Timeout Counter is used during DMA mode data transfer operations to prevent the system from indefinitely waiting for an appropriate DMA Request Signal from a selected peripheral. During a DMA mode data transfer operation, forced interrupts may be generated and transmitted to the host in order to emulate a PIO mode data transfer operation.

Abstract: A computer system including one or more PCMCIA expansion slots allows video and/or audio capabilities to be added to the system through a standard PCMCIA interface, utilizing multimedia type PCMCIA peripheral cards. A PCMCIA host adapter integrated circuit interrogates a PCMCIA peripheral card to determine whether or not the PCMCIA peripheral card is a multimedia type PCMCIA peripheral including video or audio capability. If the PCMCIA peripheral card is a multimedia type peripheral, the PCMCIA host adapter integrated circuit couples the PCMCIA peripheral card directly to the graphics and sound controller integrated circuits, using the standard PCMCIA interface and bypassing the host system bus. Otherwise, if the PCMCIA peripheral card is a standard PCMCIA peripheral, then the PCMCIA host adapter integrated circuit interfaces communications between the PCMCIA peripheral card and the host system bus in a conventional manner.