Existing Languages

1
Existing Languages

• None of the existing HDLs could be used as
  standard tool for design, manufacturing and
  documentation of digital circuits ranging from
  ICs to complete systems.
• AHPL
• CDL
• CONLAN
• IDL
• ISPS
• TEGAS
• TI-HDL
• ZEUS

2
VHDL

• VHDL is an abbreviation of Very High Speed
  Integrated Circuit (VHSIC) Hardware Description
  Language. It was initiated by the United States
  Department of Defense in 1981 to address the
  hardware life cycle crisis, which require for a
  language with a wide range of descriptive
  capability that would work the same on any
  simulator and was independent of technology or
  design methodology. Manual lower level design
  becomes impractical as designs become large
• VHDL is used to describe the behavior and
  structure of electronic systems, but is
  particularly suited as a language to describe the
  structure and behavior of digital electronic
  hardware designs, such as ASICs and FPGAs as well
  as conventional digital circuits.

3
The Advantages of VHDL

• Increase productivity
• Minimum cost and time
• Better design
• Reusability for new technology
• Tool independence

4
Increase productivity

• VHDL can increase productivity by shorten the
  time to market.
• Behavioral simulation can reduce design time by
  allowing design problems to be detected early on,
  avoiding the need to rework designs at gate
  level.

Minimum cost and time

• VHDL make the most reliable design process, with
  minimum cost and time.

5
Better design

• Behavioral simulation permits design optimization
  by exploring alternative architectures, resulting
  in better designs.

6
Reusability for new technology

• System may be used again in other instances for
  which it may or may not have been specifically
  intended. To move a design to a new technology, a
  specification needs not to start from scratch or
  reverse-engineer. Instead, the design tree to a
  behavioral VHDL description can be implement in
  the new technology knowing that the correct
  functionality preserved.

7
Tool independence

• VHDL descriptions of hardware design and test
  benches are portable between design tools, and
  portable between design centers and project
  partners.
• Simulation/synthesis companies
• ALDEC, ALTERA, CYPRESS, MENTOR GRAPHICS,
  MODELSIM, SYNOPSYS, CADENCE, XILINX etc.

8
VHDL vs Verilog
9
VHDL vs Verilog (cont.)