Invention Grant
US08219847B2 Arithmetic unit and arithmetic processing method for operating with higher and lower clock frequencies
失效
算术单元和算术处理方法,用于操作较高和较低的时钟频率
- Patent Title: Arithmetic unit and arithmetic processing method for operating with higher and lower clock frequencies
- Patent Title (中): 算术单元和算术处理方法,用于操作较高和较低的时钟频率
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Application No.: US12604806Application Date: 2009-10-23
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Publication No.: US08219847B2Publication Date: 2012-07-10
- Inventor: Daisuke Suzuki , Minoru Saeki , Yuichiro Nariyoshi
- Applicant: Daisuke Suzuki , Minoru Saeki , Yuichiro Nariyoshi
- Applicant Address: JP Kanagawa
- Assignee: Renesas Electronics Corporation
- Current Assignee: Renesas Electronics Corporation
- Current Assignee Address: JP Kanagawa
- Agency: McDermott Will & Emery LLP
- Priority: JP2008-291177 20081113
- Main IPC: G06F1/04
- IPC: G06F1/04 ; G06F1/32

Abstract:
There is a need for providing a battery-less integrated circuit (IC) card capable of operating in accordance with a contact usage or a non-contact usage, preventing coprocessor throughput from degrading despite a decreased clock frequency for reduced power consumption under non-contact usage, and ensuring high-speed processing under non-contact usage. A dual interface card is a battery-less IC card capable of operating in accordance with a contact usage or a non-contact usage. The dual interface card operates at a high clock under contact usage and at a low clock under non-contact usage. A targeted operation comprises a plurality of different basic operations. The dual interface card comprises a basic arithmetic circuit group. Under the contact usage, the basic arithmetic circuit group performs one basic operation of the targeted operation at one cycle. Under the non-contact usage, the basic arithmetic circuit group sequentially performs at least two basic operations of the targeted operation at one cycle.
Public/Granted literature
- US20100122108A1 ARITHMETIC UNIT AND ARITHMETIC PROCESSING METHOD Public/Granted day:2010-05-13
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