An identifier is the name of a constant, variable, function, signal, entity, port, subprogram, or parameter and returns that object’s value to an operand.

Identifiers in VHDL-AMS must begin with a letter, and can comprise any combination of letters, digits, and underscores. Identifiers must not end with an underscore and must not include two successive underscore character. Also no space is allowed within an identifier since a space is a separator.

An indexed identifier is the name of one element of an array variable or signal. The expression must return a value within the array’s index range. The value returned to an operator is the specified array element.

letter { [underscore] letter_or_digit } -- identifier

letter { [underscore] letter_or_digit } (expressions) -- indexed identifier

Voltage1, power_dissipated, product_of_sums

voltage(2), current(3+1)