JPS5815737A - Lsi for control of automobile engine - Google Patents

Abstract

PURPOSE:To operate a microcomputer system without causing the necessity for further providing a specific circuit even at starting time of an engine, by constituting the microcomputer system from a CMOS.FET operated at lower limit voltage lower than battery voltage at the starting time of the engine. CONSTITUTION:In a microcomputer system, only a necessary mechanism, for instance, CPU11,I/O13, ROM12, at starting of an engine, is partially constituted by a CMOS.FET with operating lower limit voltage of about 3V, while the other part, for instance, the rest 12' of the ROM12 is contituted by a low cost NMOS. FET operated with voltage at least about 4.5V. In the above constitution, even if battery voltage is lowered at starting time of the engine, the microcomputer system can be operated without causing the necessity for further providing a particular circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an L8I (Large
8cale Integration) eclll.

BACKGROUND ART Conventionally, when controlling a car's engine using a microcombi device, a problem has been what to do when the voltage of a battery installed in the car is low.

41Ik, K when starting the engine (during cranking), the voltage may drop by about 4VK at worst. However, the conventionally used micro combinator is the well-known TTL ()
5 according to the circuit (transistor, transistor logic)
Its operation is guaranteed only at v±5%-1091.

As a countermeasure, as shown in Fig. 1, the voltage of the battery 1 is constantly monitored by the level detector 2, and when the voltage falls below a predetermined voltage, the stabilizing circuit 3 is switched to the booster circuit 4. It is possible to use a configuration in which the voltage is switched to supply the necessary voltage when starting the engine, or a special circuit in a separate system is operated without performing micro combinator control when starting the engine.

However, both methods require special circuitry and are expensive. Furthermore, the latter method has the disadvantage that micro combinatorial control cannot be performed at the time of starting.

The present invention has been made to eliminate the above-mentioned drawbacks, and its feature is that the micro combinator can be operated at a lower operating limit voltage of 3 volts, for example, lower than the battery voltage at the time of starting the engine. 8-F
I T (Olocked Oomple-menta
ry MO8φFET) or is it composed of
In other words, only the functions necessary for starting the engine are composed of 0M08 FBT that can be operated at approximately 3 volts, and the other parts are NM.
The reason is that it is composed of OB/FBT (N-channel MO8/FIT).

Hereinafter, the present invention will be explained in detail with reference to Examples.

In addition, in FIG. 2vA and FIG. 3, the same parts as in FIG. 1 are given the same symbols.

FIG. 2 is a block diagram showing the configuration of an embodiment of the automobile engine control system of the present invention.

0PU (calculation unit i+n device・>ll, ROM (Rea
dOnly Memory) 12. I 10 (
(input/output device) 13, each with an operating lower limit voltage lower than the reduced battery voltage when starting the engine;
For example, a 0MO8-FET with a lower operating voltage limit of 3 volts.
This is an LSI of a mourning micro combinator system. This basic operation is the same as that of a conventional automobile engine control system, so it will be omitted here. The same operation as before can be performed by simply inputting a cranking signal to the ROM 12 from the outside using the engine start key.

FIG. 3 is a block diagram showing the configuration of another embodiment of the present invention. In the embodiment shown in FIG. However, this may result in higher costs, so only a part of the mechanism necessary for starting the engine, such as 0PU11 + l1013 + ROM12, is replaced with 0M08/FIilT, which has a lower operating limit voltage of 3 volts.
, and other parts, for example, the remaining part 12' of the ROM 12, are replaced by an inexpensive NMOB/NMOB that operates at 4.5 volts or more.
This is an LSI made up of FIT. In addition, the above 0MO8-
Only the portion consisting of FF)T may be reduced to one chip.

To switch between engine start and normal operation, simply set the respective set buttons and the program will automatically switch between engine start and normal operation.

As explained above, according to the present invention, the microcomputer control can be performed without using any special additional circuit when starting the engine, thereby reducing the cost of the device.

[Brief explanation of the drawing]

1 FIIJ is a block configuration diagram of a conventional automobile engine control system, FIG. 2 is a block configuration diagram of an embodiment of the automobile engine control system of the present invention, and FIG. 3 is a block diagram of another embodiment of the automobile engine control system of the present invention. FIG. 2 is a block configuration diagram of an embodiment of the present invention. l...Battery, 3...Stabilization circuit, 11...
0M08・FEITFET configuration U, 12...0M08
・30M% of FET configuration 12'...NMOB・FE
ROM of T configuration, 13...Ilo. Figure 1

Claims (2)

[Claims] (1) The microcombi-ta system is composed of 0M08 FBT, which has a lower operating limit voltage than the voltage supplied from the battery when starting the engine, and can operate without a special additional circuit even when starting the engine. L8I0 for automobile engine control, characterized by (2) 0MO8-F, which has a lower operating limit voltage lower than the voltage supplied from the battery when starting the engine, provides the micro combinator system with only the functions necessary for starting the engine.
Consists of BT, other parts are N-channel MO8-FET
An L8 for automobile engine control characterized by comprising:
I.