Development and analysis of a verstile, reusable, high speed, DMA controller for custom embedded applications using the PCI bus

This thesis investigates the plausibility of designing and developing a versatile, reusable, high speed interface for custom computing applications, based on the Peripheral Component Interface (PCI) Bus. A PCI I/O board was developed, utilizing mainly Complex Programmable Logic Devices (CPLD\u27s), which included a custom Direct Memory Access (DMA) Controller to take advantage of the unique feature set of the PCI bus. The arbitration mechanisms and performance characteristics of the PCI bus are taken advantage of in order to achieve a maximum burst throughput rate of 66 Megabytes per second. Performance characteristics of the I/O board are analyzed for two separate PCI host systems. In the faster of the two systems, a 166MHz Pentium PC, a maximum aggregate throughput rate of 54 Megabytes per second for PCI burst writes was achieved. In all cases throughput increased as a function of transfer size. Due to buffering implementations in the host systems write performance was always superior to read performance. In addition to exceptional throughput capability, this implementation provides a design engineer with a versatile interface which can be mated to a number of high performance applications. The PCI I/O board\u27s external interface is implemented with a CPLD which can be quickly and easily modified to meet the needs of practically any custom interface without decreasing PCI bus performance. Using the on-board latency timer and programmable FIFO\u27s the board can be fine tuned to meet a variety of application requirements. The two main design goals were to provide unlimited bursting capability and to transfer 32-bits of data on every clock. The first was achieved through the implementation of a 32-bit burst Transfer Count register. The second goal had to be reduced by 50% due to a timing margin violation discovered during board debug