Keil uvision4 bytes occupied by various data types

View the number of bytes occupied by the Keil MDK-ARM for various data types

 

1. Define several variables to store the number of bytes of each data type.

<Stdio. h>

Unsigned char a, B, c, d, e, f, g;

Main ()

{

A = sizeof (char );

B = sizeof (short INT );

C = sizeof (INT );

D = sizeof (long );

E = sizeof (long INT );

F = sizeof (float );

G = sizeof (double );

While (1 );

}

2. view the storage address of each variable. View --- symbols window.

3. view the stored values of each address. View --- Memory window.

We can see that:

Char occupies 1 byte

Short int occupies 2 bytes

Int occupies 4 bytes

Long occupies 4 bytes

Long int occupies 4 bytes

Float occupies 4 bytes

Double occupies 8 bytes

We can define the macro as follows:

Typedef unsigned char uint8; // unsigned 8-bit integer variable
Typedef signed Char int8; // signed 8-bit integer variable
Typedef unsigned short uint16; // unsigned 16-bit integer variable
Typedef signed short int16; // signed 16-bit integer variable
Typedef unsigned int uint32; // unsigned 32-bit integer variable
Typedef signed int int32; // signed 32-bit integer variable
Typedef float fp32; // Single-precision floating point number (32-bit length)
Typedef double fp64; // double-precision floating point number (64-bit length)