Expressions in VHDL-AMS are similar to those of most high-level languages. Data elements must be of the same type, or subtypes of the same base type. Expressions perform arithmetic or logical computations by applying an operator to one or more operands. Operators specify the computation to perform, operands are the data for the computation.

Logical

• Predefined operators for types BIT and BOOLEAN.

AND | OR | NAND | NOR | XOR | XNOR | NOT

Relational

• Predefined operators for all types except files.

= | /=

• Predefined operators for scalar and discrete array types.

< | <= | > | >=

Relational operators include tests for equality (=), inequality (/=), and ordering of operands (<, <=, >, >=). The operands of each relational operator must be of the same type. The result type of each relational operator is the predefined type BOOLEAN.

Shift

sll | srl Shift left/right logical.

sla | sra Shift left/right arithmetic.

rol | ror Rotate left/right logical.

Operators for any one-dimensional array type whose element type is either of the predefined types BIT or BOOLEAN (left operant) and predefined type INTEGER (right operand). The result type of each shift operator is the same as the left operand.

Adding

• Predefined operators for any numeric type.

+ | -

• Predefined operator for any one-dimensional array type.

& Concatenate, a & b makes one array

For each of these adding operators, the operands and the result are of the same type.

Multiplying

• Predefined for any integer and any floating point type.

* | /

• Predefined for any integer type.

mod | rem a mod b takes sign of b, a rem b takes sign of a

For each of these multiplying operators, the operands and the result are of the same type.

Miscellaneous

• Predefined for any numeric type.

abs absolute value

** a** is a²

The exponential operator ** is predefined for each integer type and for each floating point type.