Patents Assigned to Sierra Semiconductor, Canada, Inc.
  • Patent number: 5522086
    Abstract: A mechanism is provided for software configuration of ISA bus cards or other devices connected to a computer processor by a bus that does not provide for sharing of an address by multiple devices. Such a device is configured under software control by selecting multiple addresses commonly used by a read-only device, writing from the computer processor to the configuration logic at one of such addresses a predetermined data word as part of a predetermined security access sequence, writing from the computer processor to the configuration logic at one of the addresses configuration information including a device based address, and the configuration logic, in response to the predetermined security access sequence, storing the configuration information in configuration registers, thereby configuring the device. The addresses used may be addresses used by a game device, such as a joystick.
    Type: Grant
    Filed: October 29, 1993
    Date of Patent: May 28, 1996
    Assignee: Sierra Semiconductor Canada, Inc.
    Inventors: Mitchell G. Burton, Mark J. Wilson
  • Patent number: 5243124
    Abstract: A computer having one or more wave tables stored therein is used to synthesize sounds represented by a series of digital samples produced at a sample rate by specifying parameters including a carrier frequency, a modulating frequency and an index of modulation. At each sample time, a modulation value determined during an immediately preceding sample time is scaled to produce a digital control signal. Also at each sample time the modulation value to be used during an immediately succeeding sample time is read from a location of a wave table determined by the modulating frequency, and a carrier value used to produce the digital samples is read from a location of a wave table determined by the carrier frequency and the digital control signal. Modulation effects are therefore delayed by one sample in order to speed execution of the method using the computer.
    Type: Grant
    Filed: March 19, 1992
    Date of Patent: September 7, 1993
    Assignee: Sierra Semiconductor, Canada, Inc.
    Inventors: Clifford Kondratiuk, Karim Mitha