Geely JL481Q, Руководство пользователя

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Microcomputer of ECU is an integration of microprocessor, memory, clock generator, timer, input/output (I/O) interface and
A/D converter in input stage in a large-scale integrated chip, i.e. single-chip microcomputer.
1. Input stage
Input stage of input signal from sensor performs preprocessing. Input signal is firstly sent to protective circuit, in some
cases through signal converter and amplifier, and then sent to microcomputer.
Signals of sensor are divided into switch quantity and analog quantity. Ignition on/off signal, camshaft position signal,
automobile speed signal and air conditioning signal etc are all switch quantities while signals of battery voltage, engine
temperature, intake temperature, air quantity, absolute pressure of intake manifold, throttle angle, excess air ratio, knock-
ing and pressure of refrigerant in air conditioner are all analog quantities. All analog signals could be processed by the
following digital microcomputer only after they pass through A/D conversion and are converted into digital signals. There-
fore, it firstly collects data of analog signals, samples and holds them at the same time.
Signals of revolution and crankshaft position reference mark from inductive sensor are processed in a special circuit to
suppress interfering impulses.
2. Microcomputer
Microcomputer of engine ECU is integrated into a single-chip, and consists of:
(1) Microprocessor. Also called Central Processing unit (CPU), it mainly consists of three parts:
a. Arithmetical logic unit
b. Register block
c. Controller
(2) System bus. Internal bus performs data transmission between individual parts in a single-chip microcomputer. External
bus performs data transmission between single-chip microcomputer and other parts. External bus is also called system
bus, which could be divided into data bus, address bus and control bus.
(3) Memory. The memory serves to store data in the form of binary code, and mainly consists of:
a. Memory
b. Data register
c. Address register and decoder
d. Memory controller
(1) A/D converter
(2) Input/output (I/O) interface
(3) Clock generator
(4) Timer
(5) Capture/compare (CAPCOM) unit
(6) Watchdog timer
(7) Interrupt system
3. Output stage
ECU output stage serves to send control signal to actuator in the electronic control system according to the command of
Pretttproctessor in the micfxxsssssocontroller. Control of microprocessor on output stage is carried out by means of
controlling the position of impulse, its length and duty ratio.
(1) Output stage of fuel injection
Microprocessor controls the width of impulse transmitted by the output stage of fuel injection
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