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. 16, 2006
Filed:
Oct. 29, 2001
Yoshiyuki Kamihara, Sapporo, JP;
Yoshiyuki Kamihara, Sapporo, JP;
Seiko Epson Corporation, Tokyo, JP;
Abstract
The objective is to provide a data transfer control device and electronic equipment that make it possible to switch the frequency of a generated clock dynamically, without causing any operating errors. The data transfer control device includes a clock generation circuit which generates clocks CLKH and CLKF and a clock control circuit which generates a system clock SYCLK based on CLKH and CLKF. The autonomous operation of a PLLM that generates CLKF is enabled before the autonomous operation of a PLLM that generates CLKH is disabled, and the generation source of SYCLK is switched from CLKH to CLKF after the autonomous operation of the PLLM has stabilized. On condition that CLKH becomes '0', SYCLK is set to '0' for a given period only; and on condition that CLKF becomes “0”, SYCLK is generated based on CLKF. When the mode switches from HS mode FS mode under USB 2.0, the operation of the PLLM is disabled, reducing the power consumption.