Page 79 - Mechatronic Systems Modelling and Simulation with HDLs

68 4 MODELLING IN HARDWARE DESCRIPTION LANGUAGES

System

Module 1 Module 2 Module 3

Submodule 1 Submodule 2 Submodule 3 Submodule 4 Submodule 5 Submodule 6

Figure 4.3 Simulation on a mixed abstraction level

of one another. Due to this ‘interlacing’ of the engineering work in the sense of
simultaneous engineering, the design time for more complex systems can be kept
within reasonable limits. Methods for the partitioning of engineering work will
become increasingly important in the future because the organisational manage-
ment of more complex, strongly coupled systems will increasingly be the factor
that limits feasibility.

4.4 Languages

Many hardware description languages have been defined in recent years. Some of
the more widespread languages were introduced by providers of design automation
software. ‘M-HDL’ by Mentor Graphics or ‘Verilog-HDL’ by Cadence Design Sys-
tems are typical representatives of this group. In the analogue field the languages
‘MAST’ from Avant!, ‘HDL-A’ from Mentor Graphics, ‘SpectreHDL’ or ‘Verilog-
A’ from Cadence Design Systems and ‘ABCD’ from Dolphin Integration S.A., are
particularly worth mentioning. All these languages should be classified as propri-
etary hardware description languages since the associated tools could initially only
be obtained from the companies in question.
A further group of hardware description languages originated from the university
sector, such as ‘BDS’ from the University of California, Berkeley, or ‘daCapo’
from the University of Dortmund. However, these languages have only become
widespread in the academic field. Nevertheless, because of their innovative ideas
they often form the basis for commercial description languages.
2
A third group of languages is represented by VHDL, which was initially the
product of an American research programme and later became the IEEE stan-
dard 1076 as part of an expensive standardisation. The American Department of
Defense, by far the biggest user in the North American area, helped the standard to
make a breakthrough by making adherence to this standard a prerequisite for the

2 VHSIC Hardware Description Language. VHSIC = very high speed integrated circuits, American pro-
motional program for the development of particularly powerful integrated circuits.