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Patent Searching and Data


Title:
COUNTER CIRCUIT
Document Type and Number:
Japanese Patent JP2012039296
Kind Code:
A
Abstract:

To provide a counter circuit where jitters are equivalent to those of a synchronous type counter, the counter circuit making it possible to change the pulse width of the output wave of an output signal.

The counter circuit comprises: shift registers 111 to 1110 which generate frequency division setting data DB; shift registers 11 to 110 which generate data DC for determining the pulse width of a signal COUT; a register unit which loads the data DB when a signal LS is input and counts down based on the data; a first signal creation unit which outputs a signal LS when the down-count value reaches a specified value; an output creation circuit 3 which, when outputting a signal COUT, begins a pulse of the signal COUT with the same timing as the signal LS is output; and a comparison circuit 2 which outputs a pulse signal when a period from the time a count value QD reaches a specified value till the time the current value QD is acquired, as found by comparison between data DC and a count value QD, corresponds to a predetermined pulse width. The output creation circuit 3 terminates the pulse of the output signal COUT when a change in the pulse signal is detected.


Inventors:
EGAWA MASAHIKO
Application Number:
JP2010176326A
Publication Date:
February 23, 2012
Filing Date:
August 05, 2010
Export Citation:
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Assignee:
JAPAN RADIO CO LTD
International Classes:
H03K23/66
Attorney, Agent or Firm:
Harushima Shigetokiro