Chapter 5
Tools Utilized
While making this thesis work, a series of programming languages, software programs
and hardware has been used in order to design, test and implement the processor.
For creating and programming the modules themselves, VHDL was used, which is a
Hardware Description Language. C was also used for the creation of the testbench.
In terms of IDEs, the hardware simulation program Modelsim was used and for the
hardware implementation Xilinx ISE and the FPGA Vyrtex ML605.
5.1
VHDL
Hardware description languages first appeared in the late 1960s and they had the form of
conventional languages. In 1971 C. Gordon Bell and Allen Newell introduced the concept
of register transfer level to describe the behavior of circuits. Many other implementations
appeared until the late 1970s when Verilog ,the first HDL for VLSI, appeared. In 1987, a
request from the U.S. Department of Defense led to the development of VHDL (VHSIC
Hardware Description Language).HDL was based on the Ada programming language, as
well as on the experience gained with the earlier development of ISPS.[9] Initially, Verilog
and VHDL were used to document and simulate circuit designs already captured and
described in another form (such as schematic files). HDL simulation enabled engineers
to work at a higher level of abstraction than simulation at the schematic level, and thus
increased design capacity from hundreds of transistors to thousands[
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