Electrical computers and digital processing systems: processing – Processing control – Mode switch or change
Reexamination Certificate
2008-05-20
2008-05-20
Chan, Eddie (Department: 2183)
Electrical computers and digital processing systems: processing
Processing control
Mode switch or change
C712S205000
Reexamination Certificate
active
07376819
ABSTRACT:
An apparatus and method for selecting whether a central processing unit (CPU) performs instruction reading in units of 16 bits (a first word length) or in units of 32 bits (a second word length). Depending on whether instruction reading is performed in units of 16 bits or 32 bits, increment values (+2 and +4) by which a program counter (PC) is incremented are switched. Data reading or writing is performed in units of a given data length irrespective of the selecting unit. When the CPU issues a request for instruction reading in units of 16 bits or 32 bits or for data reading or writing, a bus control unit performs reading or writing a predetermined number of times according to a bus width designated for a resource located at an address specified in the request.
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Mitsuishi Naoki
Okubo Takahiro
Shibahara Shinichi
Chan Eddie
Johnson Brian P
Miles & Stockbridge P.C.
Renesas Technology Corp.
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