Architectures for Computer Vision: From Algorithm to Chip with Verilog

2 Verilog HDL, Communication, and Control

As C/C++ is a major language for programming vision algorithms, Verilog HDL/VHDL is a major language for designing analog/digital circuits. These two types of languages share common properties: a textual description consisting of expressions, statements, and control structures. One important difference is that HDLs explicitly include the notion of time and connectivity. As in other types of high-level programming languages, there are numerous design languages such as Impulse C, VHDL, Verilog, SystemC, and SystemVerilog, to name a few. In addition, Verilog HDL is one of the most widely used HDLs, along with VHDL, and its syntax is very similar to that of C, allowing vision engineers to be comfortable starting a circuit design.

This HDL was standardized in IEEE Standard 1364-2005 (IEEE 2005), resembles C, and covers a wide range constructs, from gate level to system level. SystemVerilog in IEEE Standard 1800-2012 (IEEE 2012) is a superset of Verilog-2005. In addition to the modules in Verilog-2005, SystemVerilog defines more design elements such as the program, interface, checker, package, primitive, and configuration. In addition, the language interface, VPI, in Verilog-2005 is generalized into DPI. This book is mostly based on Verilog-2005 (IEEE 2005).

This chapter introduces the Verilog syntax, the communication, and control modules. For the Verilog syntax, we will learn the minimal amount of syntax and grammar necessary for designing ...