16-02-2013, 04:12 PM
Development of a Custom Microprocessor for Automotive Control
[attachment=51231]
ABSTRACT:
This paper describes the
development of a high-performance
microprocessor-based system for control of
automotive emissions and fuel economy. The
result is a hvo-chip system consisting of a
VLSI single-chip 16-bit microprocessor with
an integral analog-to-digital (ND) converter
and precision timing circuits, and a companion
memory chip with a combination of read
only memory (ROM) and random access
memory (RAM).
Introduction
Requirements for minimum automotive
emissions and maximum fuel economy
create the need for a high-speed, accurate
control system that can operate under harsh
environmental conditions. Because of large
production volumes (millions of vehicles per
year) and long product life, customized microprocessor
technology can be developed to
meet this need using very large scale integrated
(VLSI) circuit techniques. This paper
outlines the joint Ford/Intel development of a
VLSI single-chip microprocessor with its
companion memory chip currently being
used in the production of automobiles and
light trucks.
Engine Control Requirements
Automotive engine emission and fuel
economy requirements necessitate control of
a aide range of factors. with varying degrees
of accuracy. These items include air-fuel
ratio, spark timing, and exhaust gas recirculation.
which must all be accurately controlled
to provide the best fuel economy for
most operation conditions. Spark timing
must be accurately controlled to meet engine
emission constraints under various speed and
torque outputs. Under transient driving
conditions, the control strategy for spark
becomes even more complex. It would be
extremely difficult to accomplish these complex
algorithms with a mechanical ignition
system. and virtually impossible to provide
the adaptive response of electronic controls.
Electronic modules, however, are only part
of the engine control system. Several sensors
are used to measure characteristics of temperature,
pressure, air flow, throttle position,
crankshaft position, and knock. Actuators to
control air, fuel, exhaust gas recirculation
complete the control system [ 11.
Fuel control, either feedback carburetor or
fuel injection, provides the means for maintaining
the air-fuel ratio at stoichiometry for
maximum catalyst efficiency
Custom Versus Standard LSI
Approaches
The control microprocessor can be provided
by assembling several standard, offthe-
shelf integrated circuits for a particular
application. The approach of using standard
ICs provides flexibility by adding or taking
away circuits to match the application but
requires several devices for even minimal
applications. Standard microprocessors also
include support of features. such as BCD
number systems. which are not required for
control applications.
The custom design approach offers benefits
in minimum chip count, minimum
boar&module size. and increased reliability.
System speed can also be optimized in the
custom approach by minimizing the bus
structures and drive requirements between
circuits to limit capacitance loading. Custom
design offers the opportunity to tailor the device
to the application without carrying unnecessary
capability as overhead.
8361 ROM/RAM
The instruction memory device for the
EEC-IV system is the 8361. Each 8361 provides
WK bits of program memory internally
arrayed as 4096 x 16. Each 16-bit access
requires two CPU state times (0.4 ps)
Conclusion
The use of electronics in automobiles will
continue to increase, providing improved vehicle
fuel economy and performance without
a deterioration in exhaust emissions and increased
safety and comfort [2]. Future power
train electronics will see the engine control
system expanded to include the transmission.
New transmissions will be electronically
controlled to provide smooth, indiscernible
shifts from one gear to another
[attachment=51231]
ABSTRACT:
This paper describes the
development of a high-performance
microprocessor-based system for control of
automotive emissions and fuel economy. The
result is a hvo-chip system consisting of a
VLSI single-chip 16-bit microprocessor with
an integral analog-to-digital (ND) converter
and precision timing circuits, and a companion
memory chip with a combination of read
only memory (ROM) and random access
memory (RAM).
Introduction
Requirements for minimum automotive
emissions and maximum fuel economy
create the need for a high-speed, accurate
control system that can operate under harsh
environmental conditions. Because of large
production volumes (millions of vehicles per
year) and long product life, customized microprocessor
technology can be developed to
meet this need using very large scale integrated
(VLSI) circuit techniques. This paper
outlines the joint Ford/Intel development of a
VLSI single-chip microprocessor with its
companion memory chip currently being
used in the production of automobiles and
light trucks.
Engine Control Requirements
Automotive engine emission and fuel
economy requirements necessitate control of
a aide range of factors. with varying degrees
of accuracy. These items include air-fuel
ratio, spark timing, and exhaust gas recirculation.
which must all be accurately controlled
to provide the best fuel economy for
most operation conditions. Spark timing
must be accurately controlled to meet engine
emission constraints under various speed and
torque outputs. Under transient driving
conditions, the control strategy for spark
becomes even more complex. It would be
extremely difficult to accomplish these complex
algorithms with a mechanical ignition
system. and virtually impossible to provide
the adaptive response of electronic controls.
Electronic modules, however, are only part
of the engine control system. Several sensors
are used to measure characteristics of temperature,
pressure, air flow, throttle position,
crankshaft position, and knock. Actuators to
control air, fuel, exhaust gas recirculation
complete the control system [ 11.
Fuel control, either feedback carburetor or
fuel injection, provides the means for maintaining
the air-fuel ratio at stoichiometry for
maximum catalyst efficiency
Custom Versus Standard LSI
Approaches
The control microprocessor can be provided
by assembling several standard, offthe-
shelf integrated circuits for a particular
application. The approach of using standard
ICs provides flexibility by adding or taking
away circuits to match the application but
requires several devices for even minimal
applications. Standard microprocessors also
include support of features. such as BCD
number systems. which are not required for
control applications.
The custom design approach offers benefits
in minimum chip count, minimum
boar&module size. and increased reliability.
System speed can also be optimized in the
custom approach by minimizing the bus
structures and drive requirements between
circuits to limit capacitance loading. Custom
design offers the opportunity to tailor the device
to the application without carrying unnecessary
capability as overhead.
8361 ROM/RAM
The instruction memory device for the
EEC-IV system is the 8361. Each 8361 provides
WK bits of program memory internally
arrayed as 4096 x 16. Each 16-bit access
requires two CPU state times (0.4 ps)
Conclusion
The use of electronics in automobiles will
continue to increase, providing improved vehicle
fuel economy and performance without
a deterioration in exhaust emissions and increased
safety and comfort [2]. Future power
train electronics will see the engine control
system expanded to include the transmission.
New transmissions will be electronically
controlled to provide smooth, indiscernible
shifts from one gear to another