bitset

Set bits at certain positions

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 the Bit at a 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 the Bit at a Certain Position in a 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 the Bit at a 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 the Bit When Index Is a 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 array

scalar | vector | matrix | multidimensional array

Input array, specified as a scalar, vector, matrix, or multidimensional array of fixed-point fi objects. If a has a signed numerictype, the bit representation of the stored integer is in two's complement representation.

Data Types: fixed-point fi

bit — Bit index

scalar | vector | matrix | multidimensional array

Bit index, specified as a scalar, vector, matrix, or multidimensional array of fi objects or built-in data types. bit must be a number between 1 and the word length of a, inclusive. The LSB (right-most bit) is specified by bit index 1 and the MSB (left-most bit) is specified by the word length of a.

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

11001001

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

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. v can have values of 0, or 1. Any value other than 0 is automatically set to 1. When v is nonscalar, it must have the same dimensions as one of the other inputs.

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

Output Arguments

c — Output array

scalar | vector | matrix | multidimensional array

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

Extended Capabilities

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

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