bitset

Set bit at specific location

Syntax

C = bitset(A,bit)

C = bitset(A,bit,V)

Description

C = bitset(A,bit) returns the value of A with position bit set to 1 (on).

C = bitset(A,bit,V) returns the value of A with position bit set to V.

Examples

Set Bit at Certain Position

Begin with an unsigned fixed-point fi number with a value of 5, word length 4, and fraction length 0.

a = fi(5,0,4,0);
disp(bin(a))

0101

Set the bit at position 4 to 1 (on).

c = bitset(a,4);
disp(bin(c))

1101

Set Bit at Certain Position in Vector

Consider the following fixed-point vector with word length 4 and fraction length 0.

a = fi([0 1 8 2 4],0,4,0);
disp(bin(a))

0000   0001   1000   0010   0100

In each element of vector a, set the bits at position 2 to 1.

c = bitset(a,2,1);
disp(bin(c))

0010   0011   1010   0010   0110

Set Bit at Certain Position with Fixed Point Index

Consider the following fixed-point scalar with a value of 5.

a = fi(5,0,4,0);
disp(bin(a))

0101

Set the bit at position fi(2) to 1.

c = bitset(a,fi(2),1);
disp(bin(c))

0111

Set Bit When Index Is Vector

Create a fi object with a value of pi.

a = fi(pi);
disp(bin(a))

0110010010001000

In this case, a is signed with a word length of 16.

Create a vector of the bit positions in a that you want to set to on. Then, get the binary representation of the resulting fi vector.

bit = fi([15,3,8,2]);
c = bitset(a,bit);
disp(bin(c))

0110010010001000   0110010010001100   0110010010001000   0110010010001010

Input Arguments

A — Input values

scalar | vector | matrix | multidimensional array

Input values, specified as a scalar, vector, matrix, or multidimensional array of fixed-point fi objects. If any of A, bit, or V are nonscalar, the other inputs must be scalar or arrays of the same size. If A has a signed numerictype, the bit representation of the stored integer is in two's complement representation.

Data Types: fi
Complex Number Support: Yes

bit — Bit position

integer | integer array

Bit position, specified as an integer or integer array of fi objects or built-in data types. If any of A, bit, or V are nonscalar, the other inputs must be scalar or arrays of the same size. The values of bit must be between 1 and the word length of A, inclusive. The LSB, the right-most bit, is specified by bit index 1. The MSB, the left-most bit, is specified by the word length of A.

a = fi(pi,0,8);
a.bin

ans =

    '11001001'

Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64 | fi

V — Bit value

scalar | vector | matrix | multidimensional array

Bit value of A at index bit, specified as a scalar, vector, matrix, or multidimensional array of fi objects or built-in data types. If any of A, bit, or V are nonscalar, the other inputs must be scalar or arrays of the same size. V can have values of 0 or 1. Any value other than 0 is automatically set to 1.

Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64 | fi
Complex Number Support: Yes

Output Arguments

C — Output array

scalar | vector | matrix | multidimensional array

Output array, specified as a scalar, vector, matrix, or multidimensional array of fi objects.

• If A, bit, and V are all scalars, then C is also a scalar.

• If any of A, bit, or V is an array, then C is the same size as that array.

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using MATLAB® Coder™.

HDL Code Generation
Generate VHDL, Verilog and SystemVerilog code for FPGA and ASIC designs using HDL Coder™.

Version History

Introduced before R2006a

R2022a: Scalar expansion support for fi bitset

Prior to R2022a, fi bitset required that the second and third input arguments be the same size, otherwise an error would occur.

A = fi(pi);
disp(bin(A))

bit = fi([15,3,8,2]);
C = bitset(A,bit,1);
disp(bin(C))

0110010010001000
The Second and third arguments to BITSET must be the same size.

Starting in R2022a, the input arguments A, bit, and V support scalar expansion. That is, if any of A, bit, or V are nonscalar, the other inputs can be scalar or arrays of the same size.

A = fi(pi);
disp(bin(A))

bit = fi([15,3,8,2]);
C = bitset(A,bit,1);
disp(bin(C))

0110010010001000
0110010010001000   0110010010001100   0110010010001000   0110010010001010