Unary operators take an operand on the right. Binary operators take an operand on the left and right. The table below lists operators grouped according to priority level, highest priority first. Every language has operators whose functions are to operate on operands and produce some.

We have mainly been using the STD_LOGIC and STD_LOGIC_VECTOR data types so far in this course. The BIT_VECTOR data type was introduced in the previous tutorial.

This video describes all the operators available in VHDL. Knowledge of operators will help us in programming. Concatenation – used to combine bits. XNOR there is NO order of precedence so use lots of parentheses. Can you guess the output of running this process?

Binary logical operators: and or nand nor xor xnor. Shifts operators: sll srl sla sra rol ror. These logical operators can be combined on a single line.

Parenthesis will dictate the order of operations. For example the line: . In the previous chapters, we illustrated the realization (i.e., the conceptual diagram) of basic concurrent and sequential statements. Chapter – Data Flow Descriptions.

Section – Other Operators. The previous sectioned mentioned a few different types that are available in VHDL. This section mentions some of these. While relational operators are available for all predefined data types, the logical, shift and arithmetical operators may only be used with bit and numerical values, respectively. These include logical (or Boolean), arithmetic, and relational operators.

The logical operators are listed in Figure 4. VHDL operators are used as . The NOT operator has one input and one output, whereas the remaining operators are binary . Miscellaneous operators. The operators have increasing precedence going from category (1) . The different classes of operators are summarized below. The order of precedence is the highest for the operators of class followed by class with the lowest precedence for class 1. Very useful Tool especially in wri`ng TBs.

An absolute value operator which can be applied to any numeric type in an expression.

Example: Delta = abs(A-B). The expression A xnor B returns True only when (1) A is true . Arithmetic Coding Considerations. These are arithmetic, relational , shift and rotate, concatenation, and logical operators.

We will introduce arithmetic and concatenation operators in this chapter. The rest will be introduced in the following chapters. Multiplication operators.

New condition operator , ? There is NO order of precedence.