VHDL

1
VHDL

• From Ch. 5 Hardware Description Languages

2
History

• 1980s Schematics
• 1990s Hardware Description Languages
• Increased due to the use of Programming Logic
  Devices (PLDs), Complex PLDs (CPLDs), and Field
  Programmable Gate Arrays (FPGAs)
• Today Very High Speed IC (VHSIC) Hardware
  Description Language (VHDL) and Verilog

3
HDL Tools

• Design Tools
• Text Editor
• CompilerSyntax can be checked
• Simulator
• A timed sequence of inputs (a test-bench program)
  for the hardware is used to test the design.
• Synthesizer
• Applies the design to a hardware technology (such
  as CPLDs).

4
VHDL

• Program Structure
• Entity
• A declaration of the inputs and outputs.
• Architecture
• A description of the internal behavior or
  structure.
• Templates
• Tools can provide basic structure.
• Example Xilinx Design Suite