Abstract: The present invention relates to a system and method for supporting DMA I/O devices. A PCI-PCI bridge is provided to support DMA I/O devices on the PCI bus. Through the use of two signal lines and a serial link, DMA transfers may be accomplished over the PCI bus. A PCI-ISA dock bridge is also provided to allow the system to support DMA I/O devices and ISA masters (i.e., any device including DMA I/O devices on the ISA bus that generates ISA cycles) on the ISA bus.

Abstract: A digital power management system for an analog-to-digital converter operates to cause the sample rate of the analog-to-digital converter to function at an original desired frequency so long as changing input signals are present. Whenever activity at the input of the analog-to-digital converter ceases to change, the system automatically decreases the clock signal sampling rate to a slower clock frequency, or shuts down the application of clock signals. This conserves power until a change in the analog input is detected, whereupon the system automatically increases the sample clock frequency back to the original frequency.

Abstract: An interrupt based positioning system for a joystick. A potentiometer is coupled to the joystick for supplying a voltage signal representative of a current position of the joystick. An analog-to-digital converter changes the voltage signal to a digital voltage signal which is then stored in a register. Interrupt generation logic monitors the output of the register and generates a position interrupt signal when the digital voltage signal stored in the register indicates a change in the axial position of the joystick.