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:
Feb. 20, 1996
Filed:
Oct. 21, 1993
Masao Mizutani, Kanagawa, JP;
Tomonari Sagane, Kanagawa, JP;
Sony Corporation, Tokyo, JP;
Abstract
In control using a patch correctable microcomputer, the patch correction can have no effect on the timing of the control operation of the micro computer. Call instructions CALL 1, CALL 2 . . . for shifting, in synchronism with the operation of the microcomputer, over to a patch correction program in a RAM, are intermittently inserted into a control program stored in a ROM. A reciprocal number of invalid instructions NOP are put after this patch correction program in accordance with the length of the patch correction program. After a patch correction program has been carried out, the program in the ROM is returned to after a passage of time set according to the number of invalid instructions, so that the time for execution of the program in the RAM which is based on the microcomputer call instruction can be made constant irrespective of the length of time of the patch correction program, and will therefore have no effect on the timing for carrying out the program in the ROM.