C51 provides you with a number of basic data types to use in your C programs. C51 offers you the standard C data types and also supports several data types that are unique to the 8051 platform. The following table lists the data types available in C51.
| Data Type |
Bits |
Bytes |
Value Range |
| bit† |
1 |
0 to 1 |
|
| signed char |
8 |
1 |
-128 to +127 |
| unsigned char |
8 |
1 |
0 to 255 |
| enum |
16 |
2 |
-32768 to +32767 |
| signed short |
16 |
2 |
-32768 to +32767 |
| unsigned short |
16 |
2 |
0 to 65535 |
| signed int |
16 |
2 |
-32768 to +32767 |
| unsigned int |
16 |
2 |
0 to 65535 |
| signed long |
32 |
4 |
-2147483648 to 2147483647 |
| unsigned long |
32 |
4 |
0 to 4294967295 |
| 32 |
4 |
±1.175494E-38 to ±3.402823E+38 |
|
| sbit† |
1 |
0 to 1 |
|
| sfr† |
8 |
1 |
0 to 255 |
| 16 |
2 |
0 to 65535 |
|
† The bit, sbit, sfr, and sfr16 data types are not provided in ANSI C and are unique to C51. They are described in detail in the following sections.