Method and apparatus for synchronizing data in a host memory with data in target MCU memory

Patent 5680542 Issued on October 21, 1997. Estimated Expiration Date:

June 7, 2015. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Abstract Claims Description Full Text

Patent References

Cross channel circuit for an electronic system having two or more redundant computers
Patent #: 4466098
Issued on: 08/14/1984
Inventor: Southard

System for transferring selected data words between main memory and cache with multiple data words and multiple dirty bits for each address
Patent #: 5155824
Issued on: 10/13/1992
Inventor: Edenfield, et al.

System for analysis of embedded computer systems Patent #: 5371878
Issued on: 12/06/1994
Inventor: Coker

Inventors

Assignee

Motorola, Inc.

Application

No. 485332 filed on 06/07/1995

US Classes:

714/28, Substituted emulative component (e.g., emulator microprocessor)703/28, In-circuit emulator (i.e., ICE)709/248, MULTICOMPUTER SYNCHRONIZING711/100, STORAGE ACCESSING AND CONTROL711/141, Coherency711/144, Cache status data bit711/145, Access control bit711/146, Snooping711/165, Internal relocation717/128Tracing

Examiners

Primary: Chan, Eddie P.
Assistant: Yip, Vincent

Attorney, Agent or Firm

Hayden; Bruce E.

International Classes

G06F 011/00
G06F 012/00
G06F 015/20

Abstract

A copy of data in a Host Computer is synchronized with a version located in Shared Memory in a Modular Development System (MDS). Whenever a change in one or more bits in a Line of Data in Shared Memory are detected, a MDS Line Dirty Flag is checked. If the Flag is not set, it is set and a message is sent to the Host Computer that the Line of Data is now dirty. Whenever the Host Computer receives this message for a Line of Data in its visible memory, it sends a request to the MDS to read that Line from Shared Memory and send it to the Host. Otherwise, a Host Line Dirty Flag is set. The Host Computer also sends a request to read a Line of Data when that Line of Data is scrolled onto a screen and the corresponding Host Line Dirty Flag is set.