Evolution and History of Programming Languages - Software/Hardware/System Machine languages Assembly languages Higher-level languages

1. Evolution and History of
Programming Languages
Software/Hardware/System
Dr. Kamal Gulati

2. Software Programming
Language

3. History Timeline

4. • Machine languages
• Assembly languages
• Higher-level languages
To build programs, people use languages that are similar
to human language. The results are translated into
machine code, which computers understand.
Programming languages fall into three broad categories:
The Evolution of Programming Languages

5. • Machine languages (first-generation languages) are the
most basic type of computer languages, consisting of
strings of numbers the computer's hardware can use.
• Different types of hardware use different machine
code. For example, IBM computers use different
machine language than Apple computers.
The Evolution of Programming Languages -
Machine Languages

6. • Assembly languages (second-generation languages)
are only somewhat easier to work with than machine
languages.
• To create programs in assembly language, developers
use cryptic English-like phrases to represent strings
of numbers.
• The code is then translated into object code, using a
translator called an assembler.
The Evolution of Programming Languages -
Assembly Languages

7. Assembler
Assembly
code
Object code

8. • Third-generation languages
• Fourth-generation languages
• Fifth-generation languages
Higher-level languages are more powerful than assembly
language and allow the programmer to work in a more
English-like environment.
Higher-level programming languages are divided into
three "generations," each more powerful than the last:
The Evolution of Programming Languages -
Higher-Level Languages

9. FORTAN C
COBOL C++
BASIC Java
Pascal ActiveX
• Third-generation languages (3GLs) are the first to
use true English-like phrasing, making them easier
to use than previous languages.
• 3GLs are portable, meaning the object code created
for one type of system can be translated for use on a
different type of system.
• The following languages are 3GLs:
Higher-Level Languages -
Third-Generation Languages

10. A Typical C Program Development Environment
1. Edit
2. Preprocess
3. Compile
4. Link
5. Load
6. Execute
Disk
Disk
Loader
Linker
Compiler
Preprocessor
Editor
Disk
Disk
Disk
Primary Memory
CPU
Primary Memory
1. Program is created in the
editor and stored on disk
2. Preprocessor program
processes the code
3. Compiler creates object
code and stores it on disk.
5. Loader puts program
in memory.
4. Linker links the object
code with the libraries
6. CPU takes each instruction
and executes it, possibly
storing new data values as
the program executes
• Phases of C Programs:

11. Visual Basic (VB)
VisualAge
Authoring environments
• Fourth-generation languages (4GLs) are even easier
to use than 3GLs.
• 4GLs may use a text-based environment (like a 3GL)
or may allow the programmer to work in a visual
environment, using graphical tools.
• The following languages are 4GLs:
Higher-Level Languages -
Fourth-Generation Languages

12. • Fifth-generation languages (5GLs) are an issue of
debate in the programming community – some
programmers cannot agree that they even exist.
• These high-level languages would use artificial
intelligence to create software, making 5GLs
extremely difficult to develop.
• Solve problems using constraints rather than
algorithms, used in Artificial Intelligence
•Prolog
Higher-Level Languages -
Fifth-Generation Languages

13. Summary

14. Hardware Description
Language
HDL

15. HDL
 What and why HDL??

16. Hardware Description Language
(HDL)
 Basic idea is a programming language to
describe hardware
 Initial purpose was to allow abstract
design and simulation
 Design could be verified then implemented in
hardware
 Now Synthesis tools allow direct
implementation from HDL code.
 Large improvement in designer productivity

17. HDL
 HDL allows write-run-debug cycle for
hardware development.
 Similar to programming software
 Much, much faster than design-implement-
debug
 Combined with modern Field
Programmable Gate Array chips large
complex circuits (>100000s of gates) can
be implemented.

18. HDLs
 There are many different HDLs
 Verilog HDL
 ABEL
 VHDL
 VHDL is the most common
 Large standard developed by US DoD
 VHDL = VHSIC HDL
 VHSIC = Very High Speed Integrated Circuit
 Verilog HDL is second most common
 Easier to use in many ways = better for teaching
 C - like syntax

19. Verilog HDL
 Verilog constructs are use defined
keywords
 Examples: and, or, wire, input output
 One important construct is the module
 Modules have inputs and outputs
 Modules can be built up of Verilog primatives
or of user defined submodules.

20. Example: Simple Circuit HDL
module smpl_circuit(A,B,C,x,y);
input A,B,C;
output x,y;
wire e;
and g1(e,A,B);
not g2(y, C);
or g3(x,e,y);
endmodule

21. HDL Summary
 Hardware Description Languages allow
fast design and verification of digital
circuits.
 Accurate simulation and testing requires
delays and inputs to be specified.
 There are three different levels of
abstraction for modelling circuits.

22. System Design Language
Hardware and Software
Co-design

26. 26
Traditional Design Flow

27. 27
HW/SW Codesign Flow
Concurrent design
between hardware
and software using
 Co-simulation
 Co-synthesis

28. Codesign Language
 Hardware Description
Language (HDL)
 Software Description
Language (SDL)
 People know C, so
how about languages
built on C/C++?
 SystemC
 SpecC
 Handel-C
Has no tool support. Only useful for influencing other languages.
Lacks CAD tool support
Proprietary: Not universally available

29. SystemC
v0.90
Sep. 99
SystemC History
Synopsys
ATG
Synopsys
“Fridge”
Synopsys
“Scenic”
UC
Irvine
1996
Frontier Design
A/RT Library
1991
SystemC
v1.1
Jun. 00
Abstract
Protocolsimec
1992
CoWare
“N2C”
1997
VSIA SLD Data
Types Spec (draft)
SystemC
v1.0
Apr. 00
Fixed Point
Types

30. SystemC Highlights
 Modules
 Processes
 Ports
 Signals
 Rich set of port and signal
types
 Rich set of data types
 Clocks
 Cycle-based simulation
 Multiple abstraction levels
 Communication protocols
 Debugging support
 Waveform tracing
 Features as a codesign language

31. Current System Design Methodology
C/C++
System Level Model
Analysis
Results
Refine VHDL/Verilog
Manual Conversion
Simulation
Synthesis
Rest of Process
 Problems
 Errors in manual conversion from C
to HDL
 Disconnect between system model
and HDL model
 Multiple system tests