Title:
ELECTRONIC ODOMETER
Document Type and Number:
Japanese Patent JPS63115005
Kind Code:
A
Abstract:
PURPOSE:To securely read up-to-date data out of a memory by providing an address write circuit which specifies a location in the memory where data are written by a numeral write circuit and an address memory for storing a specified memory. CONSTITUTION:Assuming that (m) is written as a data value in the nonvolatile memory 8 for addresses when the power source is turned off, the address write circuit 5 reads the (m) out and writes the data of a digital counter 2 in the (m)th memory 4 among N nonvolatile memories 4 by the numeral write circuit 3. Then when the power source is turned on, an address decision circuit 7 reads in the (m) and allows a numeral read circuit 6 read data out of the (m)th memory 4. When the output of this data to a counter 2 is completed, the decision circuit 7 operates the write circuit 5 so as to adds, for example, 1 to the data of the memory 8, so that the data value of the memory 8 becomes m+1. This operation is repeated to easily judge whether the up-to-date data is written in the memory 4, so secure data reading operation is performed and the readout time can be shortened.
Inventors:
YANAIDA YOICHI
Application Number:
JP26148186A
Publication Date:
May 19, 1988
Filing Date:
October 31, 1986
Export Citation:
Assignee:
JAPAN ENGINE VALVE MFG
International Classes:
G01C22/00; H03K21/00; (IPC1-7): G01C22/00; H03K21/00