Patents by Inventor On Ki Andrew Chu

On Ki Andrew Chu has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Circuit and method for retaining data in DRAM in a portable electronic device
    Patent number: 5825706
    Abstract: When an external reset signal EXRST is asserted received by a reset unit (6), it is synchronised with an internal clock to produce an internal reset signal INRST, which is applied to a CPU (4) and other modules in the circuit to reset them. While the internal reset signal INRST is being applied to the CPU, the rate of a refresh signal being generated by a DRAM controller (7) for refreshing data in DRAM (3) is increased. Then, when the external reset signal EXRST is disabled, a delayed reset signal DLYRST is generated and applied to the DRAM controller (7) so that it is reset. The CPU, being already reset, can then quickly reconfigure the DRAM controller and re-enable it to resume refreshing the DRAM (4), thus maintaining the data in the DRAM.
    Type: Grant
    Filed: October 27, 1997
    Date of Patent: October 20, 1998
    Assignee: Motorola, Inc.
    Inventors: Ralph Snowden, Wendy Reed, Glen James Zoerner, Wai-Kin Steven Kwan, On Ki Andrew Chu, Hing Leung Yiu