Emulator,Simulator,Logic Analyzer in Microprocessors

1. Microprocessor Based Systems
Topic: Software and Hardware
Tools
Submitted
by:
Deepak
Tathe

2. Cross Assembler
 An assembler that generates machine
language for a different type of computer than
the one the assembler is running in.
 It is used to develop programs for computers
on a chip or microprocessors used in
specialized applications that are either too
small or are otherwise incapable of handling
the development software.

3. •A cross assembler (CA) is an assembler that runs
on computer A, assembling programs for
computer B.
• A is called the source computer and B, the target
computer.
• As a result, any meta assembler is also a CA.

4. History
 The early minicomputers (made in the early to mid
1960s) were slow and had even slower I/O devices
(mostly punched paper tape and teletype terminals).
 It made sense to assemble a program on a
mainframe, where both the editor and the CA could
use fast magnetic tapes or disks, and then to transfer
the object file, on paper tape, to the minicomputer for
execution.
 They had small memories or limited instruction sets
that made it impractical to run an assembler. For such
computers, a CA was a practical solution. The same
reasons applied to the early microprocessors of the
mid to late 1970s.
 When a new computer is developed, a CA is normally
used to implement the first assembler (and perhaps,
other software).

5.  The main problems in the implementation of a CA
are:
 If the CA is to be one-pass, it cannot load the object
program directly in the memory of the target computer.
 It has to load it in the memory of the source computer,
resolve all forward references, and generate an
absolute object file.
 The object file is eventually downloaded to the target
computer.
 A difference in word size between the source and
target computers presents a problem since the CA
has to generate instructions and constants for the
target computer, but it can only use facilities available
on the source computer.
Problems in CA

6. LOGIC ANALYSERS
 A logic analyzer is an electronic instrument
that captures and displays
multiple signals from a digital system or digital
circuit
 A logic analyzer may convert the captured data
into timing diagrams, protocol decodes, state
machine traces, assembly language, or may
correlate assembly with source-level software.
 Logic analyzers can uncover hardware defects
that are not found in simulation

7. Logic Analysers
They appeared shortly after the first microprocessors were used
because to fault find these circuits required the instrument to
have access to a large number of lines, more than could be
seen using a conventional oscilloscope.

8. Characteristics
 Provide a time display of logic states: Logic
analysers possess a horizontal time axis and a
vertical axis to indicate a logic high or low states. In
this way a picture of the digital lines can be easily
displayed.
 Multiple channels: Logic analyzers are designed
to monitor a large number of digital lines. As logic
analyzers are optimised for monitoring a large
number of digital circuits, typically they may have
anywhere between about 32 and 200+ channels
they can monitor, each channel monitoring one
digital line

9. Characteristics
 Displays logic states: The vertical display on the
analyser displays the logic state as a high of low
state. The signals enter the various channels and
are converted into a high or low state for further
processing within the analyser. It provides a logic
timing diagram of the various lines being monitored.
 Does NOT display analogue information
: These test instruments do not present any
analogue information, and in this way they differ
from an oscilloscope. They are purely aimed at
monitoring the logic operation of the system. If any
analogue information is required, then an
oscilloscope must be used in addition.

10. Simulator
 Simulation is based on the process of
modeling a real phenomenon with a set of
mathematical formula.
 Simulation Software with real time response is
often used for Industrial Applications
 It is used to replicate the behaviour of an
actual electronic device or circuit

11. Simulator for Microprocessor

12. Benefits of simulator
 Evaluating different hardware designs without building
costly physical hardware systems.
 Enabling the opportunities to access non-existing
computer components or systems
 Obtaining detailed performance metrics: A single
execution of simulators can often generate a large set
of performance data.
 Debugging: Debugging on real hardware typically
require re-booting and re-running the code to
reproduce the problems. In contrast, some simulators
have a fully controlled environment and allow software
developers to run code backward once an error is
detected.

13. Emulator
 An emulator is hardware or software that
enables one computer system (called the host)
to behave like another computer system
(called the guest).
 An emulator typically enables the host system
to run software or use peripheral devices
designed for the guest system.
 Emulation refers to the ability of a computer
program in an electronic device to emulate (or
imitate) another program or device.

14. Emulator