# What is the difference between mod and REM in VHDL?

Table of Contents

## What is the difference between mod and REM in VHDL?

The advantage is that a mod n is a repeated sawtooth graph when a is increasing even through zero, which is important in some calculations. The rem operator gives the remainder for the regular integer division a / n that rounds towards 0 (truncated division), so a = (a / n) * n + (a rem n) .

### What is mod in VHDL?

In VHDL – Modulo ( “mod” ) is an operator that returns the reminder of the division of 2 numbers. Example : signal result_1 , result_2 , result_3 , result_4 : integer ; result_1 = 9 mod 3 ; — result will equal 0. result_2 = 9 mod 4 ; — result will equal 1.

What does /= mean in VHDL?

Operator: /= The inequality operator which can be used in an expression on any type except file types. The resulting type of an expression using this operator is Boolean (that is, True or False). The expression “A /= B” returns True only if A and B are not equal.

How do you check for equality in VHDL?

Relational operators

1. Test for equality = and inequality /=
2. Test for less than < and less than or equal <=
3. Test for greater than > and greater than or equal >=

## Is MOD operator synthesizable?

In VHDL/verilog MOD ,REM and DIVISION operators are not synthesizable. Division is only possible when the second operand is a power of 2. even if you want to traverse your code using a loop to find the remainder you need to put a constant in the condition segment to get your code synthesized.

### What are different data types in VHDL?

VHDL Data Types

• BIT. The BIT data type can only have the value 0 or 1.
• BIT_VECTOR. The BIT_VECTOR data type is the vector version of the BIT type consisting of two or more bits.
• STD_LOGIC.
• STD_LOGIC_VECTOR.
• Logical Operators.
• Arithmetic Operators.
• Comparison Operators.
• Shift Operators.

What is the difference between := and <= in VHDL?

The rules are a little more complex than this, but basically: you use <= to do signal assignment, which takes effect on the next delta cycle. You use := to do variable assignment, which takes place immediately. So if you have a signal, you always use <= . If you have a variable, you always use := .

Can you compare vectors in VHDL?

The answer is yes, you can compare two array types of the same type and subtype indication directly.

## Which operator has highest precedence in VHDL?

The logical operators and, or, nand, nor, xor, xnor and not are defined for BIT and BOOLEAN types, as well as for one-dimensional arrays containing the elements of BIT and BOOLEAN. All these operators have the lowest priority, except for the operator not, which has the highest priority.

### What returns the modulus operator in output?

The modulo division operator produces the remainder of an integer division. produces the remainder when x is divided by y. Return Value: If y completely divides x, the result of the expression is 0.

Is mod synthesizable VHDL?

Is modulus synthesizable Verilog?

Re: verilog modulo operator It’s not synthesizable is your second operand is not 2.

## What is array in VHDL?

An array is an object that is a collection of elements of the same type. VHDL supports N-dimensional arrays, but VHDL Compiler supports only one-dimensional arrays. Array ele- ments can be of any type. An array has an index whose value selects each element.

### What is the difference between bit and Std_logic data types?

Bit is a predefined type and only can only have the value 0 or 1 . The Bit type is an idealized value. type Bit is (‘0’, ‘1’); std_logic is part of the std_logic_1164 package and provides more realistic modeling of signals within a digital system.

What is std_logic_vector in VHDL?

The VHDL keyword “std_logic_vector” defines a vector of elements of type std_logic. For example, std_logic_vector(0 to 2) represents a three-element vector of std_logic data type, with the index range extending from 0 to 2.

Why library is used in VHDL?

A package can be shared across many VHDL models. A package can also contains user defined data types and constants. A library is a collection of related packages. Packages and libraries serve as repositories for functions, procedures, and data types.

• September 25, 2022