The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 05, 1999
Filed:
Oct. 23, 1997
John Michael Hudson, Austin, TX (US);
Donald L Tietjen, Austin, TX (US);
Terry L Biggs, Austin, TX (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A data processing system (10) and method is used to recover a CPU from faulty operation. A single timer (38) is used to enable recovery operations. When the timer (38) experiences a first time-out event, a software watchdog interrupt (28) is generated. If the software interrupt (28) is properly handled before another consecutive/subsequent watchdog time out occurs, normal software execution will resume. However, if the software watchdog interrupt is not processed and the watchdog timer (38) experiences a second time-out event while the watchdog time-out interrupt (28) is pending, the timer (38) will generate a bus transfer termination signal (30) and set a status bit (270) within a watchdog status register (44). This assertion of termination signal (30) and the setting of the bit (270) allows the microprocessor to determine that a locked bus state exists. In response to the signal (30) and the bit (270), the locked bus (one or more of busses 22, 24, and/or 26) will attempt to recover from the locked bus state.