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:
May. 20, 2003
Filed:
Jul. 01, 2002
Tomoaki Ando, Fujieda, JP;
Yamaha Corporation, Hamamatsu, JP;
Abstract
A data write circuit is interposed between a CPU and memory, both of which operate based on the same number of bits (e.g., thirty-two bits). The CPU produces address data for designating a specific address in the memory, and access mode designation data for designating one of a byte access mode, half-word access mode, and word access mode. The data write circuit comprises a decoder for decoding the access mode designation data, a logic circuit for generating selection signals, and four selectors, each of which deals with 8-bit data consisting of eight prescribed bits of the original thirty-two bits. Each selector selects either first data read from the memory or second data output from the CPU. Therefore, each selector is capable of selecting the second data, which are substituted for the first data in the memory. Thus, it is possible to perform write operations in desired units in the memory.