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:
Dec. 28, 1993
Filed:
Dec. 23, 1991
Alan L Stahl, Peoria, IL (US);
Caterpillar Inc., Peoria, IL (US);
Abstract
A method is provided for executing a subroutine in a computer which includes a memory and a stack. The memory has a plurality of sequentially ordered memory address locations referenced by respective address codes. The subroutine is stored in a preselected range of memory locations. The method includes storing a signature word on the stack, the signature word corresponding to an entry address code in memory for the subroutine; storing a return address on the stack, the return address code corresponding to a memory location where control is to be passed after execution of the subroutine; passing control to the subroutine entry address; executing the subroutine; comparing the signature word stored on the stack with the subroutine entry address code; passing control to the return address if the compared values are equal; and executing a software interrupt if the compared values are not equal.