As the years go by, the automotive
industry seeks to innovate the market more and more, and to reach new segments
it must keep those customers most loyal to its brands happy. In the United
States, the Environmental Protection Agency (EPA) appointed the Society of
Automotive Engineers (SAE) to design a communication protocol that would allow
any technician, anywhere, to use low-cost equipment and software to have the
possibility of Update the ECU firmware in order to install the improvements
implemented by each manufacturer.
Now, the components that must be
known in automotive computer programming are the types of memory. It is
important to know the procedure perfectly and select the appropriate equipment,
since there are alternatives on the interface market that can cause confusion
when programming. Additionally, there is a possibility that they are not
compatible with the manufacturer's software. So, let's see concisely what each
of these memories is about.
Within the wide range of Memories
that come mounted in automotive electronic control modules (ECM, PCM), three
well-defined Groups can be established. Of which we can identify them taking
into account their physical characteristics, these memories can be DIL type,
PLCC type memory and SOP type memory.
DIL TYPE MEMORY:
This package was one of the first
used for cars equipped with electronic injection since 1990. As can be seen in
the figure, it has 2 lines with legs or access pins, these can be 28 or 32
pins. A mark or notch can be seen on its encapsulation, we can take this mark
as a guide to orient ourselves regarding its numbering, this guide will
indicate the location of pin 1 of the memory. We will also find a window in the
middle of the component which tells us that we can erase its data with ultraviolet
rays.
PLCC TYPE MEMORY:
This encapsulation was the second
used by automotive terminals, it itself has a reduced size and the
configuration of its legs surrounds all 4 sides unlike its predecessor (DIL)
the number of legs can be 32, 44, 48 legs. The particular thing about this
configuration is that the legs or pins are inwards and their mounting is
superficial to the motherboard. This simplifies the size of the motherboard and
also provides greater capacity inside. These types of memories are electrically
erased. On one side it has a mark that indicates the pin 1 position. They can
be found mounted directly on the plate as well as on a socket.
SOP TYPE MEMORY:
This encapsulation is one of the
most used today, it has a storage capacity of 2 to 32 megabytes in automotive
use, this encapsulation achieved both in its cost, capacity and space a
commitment adopted by automotive electronics manufacturers. The number of pins
used is 44 or 48 terminals, it also has a mark which indicates the position of
pin 1. This Memory can be electrically erased.
AUTOMOTIVE MICROPROCESSORS
Microprocessors are integrated circuits that simply execute
general-purpose instructions, working with a program of instructions that are
provided by a programmer. This program tells the microprocessor to perform long
sequences of very simple actions to accomplish useful tasks, such as those
intended by the programmer. They have input and output devices, the input
devices provide information from the outside world to the system, most microprocessor
inputs can process only Digital input signals, at the same voltage level as
that of the power supply. A level of 0 Volts is equivalent to circuit ground,
and the positive level of the power supply is typically 5 Volts. Output devices
are used to communicate the information or actions of the system with the
outside world, most of the outputs are digital logic level signals, which are
used to drive LEDs or electrical devices such as relays or actuators.