Electronics Engineering (ELEX) Board Practice Exam

How are statements evaluated in VHDL between BEGIN and END?

1. Parallelly

2. Serially

3. Randomly

4. Vectorially

The correct answer is: Serially

In VHDL (VHSIC Hardware Description Language), statements that are placed between the keywords BEGIN and END are evaluated serially. This means that the execution of each statement occurs one after the other, in the order they are written. This behavior is crucial for designing sequential operations where the outcome of one statement may influence the next. By following a serial evaluation, designers can ensure a precise flow of control and data within their designs, leading to predictable and correct behavior of digital systems modeled in VHDL. In contrast, parallel evaluation would allow statements to execute simultaneously, which is not the case in sequential blocks defined by BEGIN and END. Random evaluation doesn’t apply in programming context, as it would lead to unpredictable results and defeat the purpose of structured programming logic. Vectorial evaluation is not a term used in this context and doesn't accurately describe the execution flow in VHDL blocks.