JP2001060146A - A/d converter controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To acquire latest A/D converted data as necessary without increasing the load of software and without increasing power consumption, too. SOLUTION: Ordinarily, start is periodically performed from a start timer 4 through a switching control circuit 6, an A/D converter access control circuit 2 executes an access sequence to an A/D converter 1 and when the A/D converted data latest at that time point are required in emergency, switching is performed by a switching circuit 6. Then, software S is started through a start control circuit 5 and the A/D converter access control circuit 2 executes the access sequence to the A/D converter 1. Thus, the latest A/D converted data can be acquired as necessary without increasing the load of the software and without increasing the power consumption.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for controlling an A / D converter mounted on a vehicle-mounted navigation device or the like.

[0002]

2. Description of the Related Art A conventional device for controlling an A / D converter will be described with reference to FIGS. As shown in FIG. 2, a conventional A / D converter control device includes an A / D converter 11, an A / D converter control circuit 12 for controlling access to the A / D converter 11, and an A / D converter 11. A / D for storing A / D conversion data to be output
Conversion data storage control circuit 13 and A / D converter 11
And a start timer 14 for activating access to the server, and a predetermined operation is executed by software S which is an application program.

A / D converter access control circuit 12
Is started periodically by the start timer 14 and the A / D
An access sequence is performed to the converter 11, the A / D conversion data is overwritten and stored in the A / D conversion data storage control circuit 13, and the software S is read out and uses the A / D conversion data at irregular intervals. I was

As shown in FIG. 3, another conventional A / D converter is used.
The converter control device includes an A / D converter 21 and an A / D converter.
An A / D converter control circuit 22 for controlling access to the D converter 21; an A / D conversion data storage control circuit 23 for storing A / D conversion data output from the A / D converter 21 and notifying the end; And an activation control circuit 24 activated by S.

A / D converter access control circuit 22
Is directly activated by the software S through the activation control circuit 24, performs an access sequence to the A / D converter 21, overwrites the A / D conversion data in the A / D conversion data storage control circuit 23, and performs a completion notification, The software S is configured to read and use the A / D conversion data.

[0006]

However, in the above-described conventional A / D converter control device, when the A / D conversion data is acquired by activating the activation timer 4 as shown in FIG. Needs the latest A / D conversion data, the A / D conversion data stored in the A / D conversion data storage control circuit 13 just before activation by the timer.
There is a problem that the / D conversion data is out of date at that time, and as a countermeasure against this, if the startup interval by the startup timer 14 is shortened, the power consumption becomes large.

[0007] Further, as shown in FIG.
When the A / D conversion data is acquired by the activation by the software, the software S has to be activated every time, so that the load on the software S increases and the processing speed of the entire system decreases.

The present invention solves the above-mentioned problems of the prior art, and does not increase the power consumption and does not increase the load on the software, so that the latest A / D conversion data is required when the latest A / D conversion data is required. An object of the present invention is to provide an excellent A / D converter control device capable of acquiring D conversion data.

[0009]

An A / D converter control device according to the present invention includes a means for periodically acquiring A / D conversion data of an A / D converter, and an A / D converter which is activated by software to activate the A / D converter. It has a configuration including means for acquiring A / D conversion data and control means for switching between the two means. With this configuration, the latest A / D conversion data can be obtained when the latest A / D conversion data is required without increasing power consumption and increasing the load on software.

Further, the A / D converter control device of the present invention comprises an access control means for controlling an access to the A / D converter, and an A / D converter which outputs from the A / D converter.
Data storage control means for storing the conversion data;
A timer means for activating access to the D converter; a start control means controlled by software; and a switching control means for switching between activation from the timer means and activation from the activation control means. I have. With this configuration, it is possible to obtain the latest A / D conversion data when the latest A / D conversion data is required without increasing power consumption and increasing the load on software.

[0011]

Embodiments of the present invention will be described below with reference to FIG. As shown in FIG. 1, the A / D converter control device according to the present embodiment includes an A / D converter 1, an A / D converter access control circuit 2 for controlling access to the A / D converter 1, and an A / D converter access control circuit 2. An A / D conversion data storage control circuit 3 for storing A / D conversion data output from the D converter 1 and notifying the end of the A / D conversion data;
A start timer 4 for starting access to the converter 1;
An activation control circuit 5 activated by the software S;
A switching control circuit 6 for switching between activation from the activation timer 4 and activation from the activation control circuit 5 is provided.

Next, the operation of the above embodiment will be described. First, at normal time, the start timer 4 starts periodically, the A / D converter access control circuit 2 executes an access sequence, and converts A / D conversion data output from the A / D converter 1 into A / D data. Conversion data storage control circuit 3
To be stored.

When the latest A / D conversion data is urgently needed, the software S instructs the activation control circuit 5 to activate, and activates the A / D converter access control circuit 2 through the switching control circuit 6. Performs an access sequence to the A / D converter 1 and converts the obtained A / D converted data into A / D data.
The data is stored in the D-conversion data storage control circuit 3 to notify the end. At this time, the switching control circuit 6 performs arbitration between the activation from the activation timer 4 and the activation from the activation control circuit 5, and performs control so that no inconvenience occurs.

As described above, according to the present embodiment, the A / D conversion data is periodically transmitted to the A / D conversion
Since the data can be stored and displayed in the / D conversion data storage control circuit 3, the load on the software S can be reduced. When the latest A / D conversion data is urgently needed, the A / D conversion data can be acquired by activating the activation control circuit 5 by the software S. Therefore, the latest A / D conversion data can be obtained without increasing power consumption. You can get data.

In the above description, the switching control circuit 6 switches between activation by the activation timer 4 and activation by the software S.
However, the present invention can be similarly applied to a case where the access sequence to the A / D converter 1 started by the start timer 4 and the access sequence itself started by the software S are switched.

[0016]

As described above, according to the present invention, the access sequence to the A / D converter is periodically started by the timer at normal times, the A / D conversion data is stored in the register, and the latest When the A / D conversion data is needed, it is switched to activation by software, the access sequence to the A / D converter is executed, the latest A / D conversion data is stored in the register, and the end notification is performed. The latest A / D conversion data is required when the latest A / D conversion data is needed without increasing the load on the software.
An excellent effect that D conversion data can be obtained is obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of an A / D converter control device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a schematic configuration of a conventional timer-activated A / D converter control device;

FIG. 3 is a block diagram showing a schematic configuration of a conventional software-activated A / D converter control device.

[Explanation of symbols]

 1 A / D converter 2 A / D converter access control circuit 3 A / D conversion data storage control circuit 4 Start timer 5 Start control circuit 6 Switching control circuit S software

Claims (2)

[Claims] A means for periodically acquiring A / D conversion data of the A / D converter; a means activated by software to acquire A / D conversion data of the A / D converter; and the two means. A / D converter control device, comprising: control means for switching between the two. 2. An access control means for controlling access to an A / D converter, a data storage control means for storing A / D conversion data output from the A / D converter, and an access to the A / D converter. An A / D converter control device, comprising: timer means for activating the program, activation control means controlled by software, and switching control means for switching between activation from the timer means and activation from the activation control means.