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:
Aug. 07, 2012
Filed:
May. 22, 2007
Tatsuhiko Murata, Kyoto, JP;
Masayu Fujiwara, Kyoto, JP;
Tomoki Yamamoto, Kyoto, JP;
Takeshi Matsuzaki, Kyoto, JP;
Tatsuhiko Murata, Kyoto, JP;
Masayu Fujiwara, Kyoto, JP;
Tomoki Yamamoto, Kyoto, JP;
Takeshi Matsuzaki, Kyoto, JP;
Rohm Co., Ltd., Kyoto, JP;
Abstract
A serial I/F has: a FIFO portion to which m- or n-bit (m<n) parallel data is written based on PCLK; a FIFO reader that reads the parallel data written to the FIFO portion m bits at a time based on FCLK; a parallel/serial converter that converts the m-bit parallel data read by the FIFO reader into 1-bit serial data based on PLLCLK; a PLL circuit that produces PLLCLK by multiplying PCLK by a factor of m or n; and a frequency divider circuit that produces FCLK by dividing the frequency of PLLCLK by m. Here, the multiplication factor of the PLL circuit is so controlled as to be changed according to the number of bits of the parallel data written to the FIFO portion. This makes it possible to flexibly deal with parallel inputs having different bus widths without unduly increasing a device scale and cost.