发明名称 |
ADPLL CIRCUIT, SEMICONDUCTOR DEVICE, AND PORTABLE INFORMATION DEVICE |
摘要 |
The present invention provides ABS precision improving means under ADPLL environment or environment close to the ADPLL environment and realizes shortening of process time of the ABS. In a digital frequency comparator in an ABS circuit, a DFF for storing an initial phase difference in a DPE signal output from a DPFD is prepared. Immediately after start of ABS operation, a DPE signal output from the DPFD is recorded as a signal expressing an initial phase difference in an internal circuit of the DPFD into the DFF. After that, the digital frequency comparator performs ABS by using a signal obtained by subtracting the initial phase error recorded in the DFF from an input DPE signal, thereby realizing high-speed and stabilized ABS operation.
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申请公布号 |
US2011140747(A1) |
申请公布日期 |
2011.06.16 |
申请号 |
US20100955192 |
申请日期 |
2010.11.29 |
申请人 |
RENESAS ELECTRONICS CORPORATION |
发明人 |
ENDO RYO;SHIMBO JIRO;KITAMURA TOMOMITSU |
分类号 |
H03L7/08 |
主分类号 |
H03L7/08 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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