Electrical computers and digital data processing systems: input/ – Input/output data processing – Input/output command process
Reexamination Certificate
2001-03-22
2003-10-28
Huynh, Kim (Department: 2182)
Electrical computers and digital data processing systems: input/
Input/output data processing
Input/output command process
C710S036000, C710S105000, C712S225000, C709S201000
Reexamination Certificate
active
06640259
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to, for example, an electronic control apparatus into which a microprocessor used for fuel supply control of an engine for automobile is built, and particularly to a vehicle-mounted electronic control apparatus improved so as to standardize the apparatus in relation to control of various vehicles while miniaturizing the apparatus by improving handling of multiple input/output signals.
2. Description of the Related Art
FIG. 7
shows a typical block circuit diagram in a conventional electronic control apparatus of this kind, and an ECU (engine control unit)
1
formed of one printed board mainly comprises a large LSI (integrated circuit parts)
2
, and the LSI
2
is formed by connecting a CPU (microprocessor)
3
, nonvolatile flash memory
4
, RAM
5
, a data selector
6
for input, an A/D converter
7
, output latch memory
8
, etc. through a data bus
30
.
The ECU
1
operates by receiving supply of a control power from a power unit
9
to which a power is supplied from a vehicle-mounted battery
10
through a power line
11
and a power switch
12
, and execution programs for the above described or control constants for engine control are previously stored in the nonvolatile flash memory
4
.
On the other hand, multiple on-off input signals from various sensor switches
13
are supplied from a bleeder resistor
14
acting as a pull-up or pull-down resistor to a comparator
19
through a series resistor
15
and a parallel capacitor
16
constructing a noise filter. An input resistor
17
and a positive feedback resistor
18
are connected to the comparator
19
and when a voltage applied to both ends of the parallel capacitor
16
exceeds a reference voltage applied to a negative side terminal of the comparator
19
, a signal of logic “H” is supplied to the data selector
6
.
However, when the voltage applied to both ends of the parallel capacitor
16
drops, input by the positive feedback resistor
18
is added, so that the voltage drops to a voltage lower than the reference voltage, and whereby an output of the comparator
19
returns to logic “L”.
In this manner, the comparator
19
acts as a comparator for level decision including a hysteresis function, and it is constructed so that outputs of multiple comparators
19
are stored in the RAM
5
through the data selector
6
and the data bus
30
.
Incidentally, the data selector
6
handles, for example, an input of 16 bits and produces an output to the data bus
30
when a chip select signal is received from the CPU
3
. The number of inputs extends to several tens and a plurality of the data selectors are used.
Also, multiple analog signals from various analog sensors
20
are supplied to the A/D converter
7
through a series resistor
21
and a parallel capacitor
22
constructing a noise filter, and digital outputs of the A/D converters receiving a chip select signal from the CPU
3
are stored in the RAM
5
through the data bus
30
.
A control output of the CPU
3
is stored in the latch memory
8
through the data bus
30
and drives an external load
26
through an output transistor
23
, and a plurality of the latch memory are used to cope with a number of control outputs and it is constructed so that the control output is stored to the latch memory chip-selected by the CPU
3
.
Incidentally, numeral
24
denotes a base resistor for driving of the transistor
23
, and numeral
25
denotes a ballast resistor connected between a base and an emitter of the transistor
23
, and numeral
27
denotes a power relay for feed to the external load
26
.
In the conventional apparatus constructed in this manner, there were problems in that a scale of the LSI
2
becomes large since the CPU
3
handles extremely multiple inputs/outputs and capacitors with various capacities need to be used in the parallel capacitors
16
,
22
acting as the noise filters in order to ensure an intended filter constant and thus standardization is difficult and large capacitors need to be used in order to ensure a large filter constant, and thus the ECU
1
becomes large-scale.
As means for reducing input/output terminals of the LSI
2
to do miniaturization, as shown in “input/output processing IC” disclosed in JP-A-7-13912, a method of communicating multiple input/output signals in a time sharing manner using serial communication blocks is proposed.
However, in this method, there are problems in that noise filters with various capacities are necessary and it is not suitable for standardization of an apparatus and also a capacitor with a large capacity is required in order to ensure a sufficient filter constant and it is also not suitable for miniaturization of the apparatus.
On the other hand, a concept of using a digital filter as the noise filter to the on-off input signals to control the filter constant by a microprocessor is publicly known.
For example, in “programmable controller” disclosed in JP-A-5-119811, there is provided a filter constant change instruction capable of changing a sampling cycle while adopting an input logical value to store the value in input image memory when the input logical values of an external input signal sampled are the same value continuously by plural times.
Though this method is characterized in that the filter constant can freely be changed, in the case of handling multiple input signals, there is a problem in that a load of the microprocessor increases and control response, which is the primary purpose of the microprocessor, decreases.
In addition, as the digital filter to the on-off input signals, as shown in “data storage control apparatus” disclosed in JP-A-2000-89974, there is also means constructed so as to provide a shift register as hardware and perform sampling processing in a manner similar to the concept.
Also, in “switched capacitor filter” disclosed in JP-A-9-83301, a digital filter using a switched capacitor filter is indicated as a noise filter to analog input signals of multichannel.
Also in this case, there is a problem in that a load of the microprocessor increases and control response, which is the primary purpose of the microprocessor, further becomes less in the case of handling multiple analog input signals.
In addition, means constructed so as to switch resistance of an analog filter by resistor/capacitor in a multistage manner and change a filter constant is indicated in “microcomputer” disclosed in JP-A-8-305681, or a digital filter of a moving average method for handling an arithmetic average value of plural time series sampling data as data of current time after converting an analog value into a digital value is indicated in “digital filter method” disclosed in JP-A-2000-68833.
Moreover, there are the following public examples in relation to writing of programs or transfer processing associated with the invention.
Means for providing a main CPU and a sub CPU, and transferring program data of the sub CPU from ROM of the main CPU to RAM of the sub CPU and eliminating ROM of the sub CPU is proposed in “program transfer apparatus” disclosed in JP-A-7-334476.
Also, a transfer writing control method of a microprocessor for vehicle-mounted control apparatus for providing ROM capable of writing and erasing of program data by transfer of program data to be switched from the outside is proposed in “vehicle-mounted control apparatus” disclosed in JP-A-63-223901.
The related arts described above are partial miniaturization and standardization arts, and the fact that full-dress miniaturization and standardization into which these arts are integrated are not performed has been already described.
Particularly, there was a problem in that a decrease in control ability and response, which is the primary purpose of a microprocessor, cannot be avoided in order to achieve the miniaturization and standardization of input/output circuit parts of the microprocessor.
SUMMARY OF THE INVENTION
A first object of the invention is to achieve miniaturization and standardization of the whole control apparatus by miniaturizing input
Gokan Hiroshi
Hashimoto Kohji
Kitta Mitsuhiro
Nakamoto Katsuya
Huynh Kim
Mai Rijue
Sughrue & Mion, PLLC
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