User manual

MPLAB
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XC8 C Compiler User’s Guide
DS52053B-page 144  2012 Microchip Technology Inc.
Signed values are stored as a two’s complement integer value.
The range of values capable of being held by these types is summarized in Table 5-2
The symbols in this table are preprocessor macros which are available after including
<limits.h> in your source code. As the size of data types are not fully specified by
the ANSI Standard, these macros allow for more portable code which can check the
limits of the range of values held by the type on this implementation.
The macros associated with the short long type are non-standard macros available
in this implementation; those associated with the long long types are defined by the
C99 Standard.
Macros are also available in <stdint.h> which define values associated with
fixed-width types.
When specifying a signed or unsigned short int, short long int, long int
or long long int type, the keyword int may be omitted. Thus a variable declared
as short will contain a signed short int and a variable declared as unsigned
short will contain an unsigned short int.
It is a common misconception that the C char types are intended purely for ASCII char-
acter manipulation. However, the C language makes no guarantee that the default
character representation is even ASCII. (This implementation does use ASCII as the
character representation.) The char types are the smallest of the multi-bit integer
sizes, and behave in all respects like integers. The reason for the name “char” is his-
torical and does not mean that char can only be used to represent characters. It is pos-
sible to freely mix char values with values of other types in C expressions. With the
MPLAB XC8 C Compiler, the char types are used for a number of purposes – as 8-bit
integers, as storage for ASCII characters, and for access to I/O locations.
TABLE 5-2: RANGES OF INTEGER TYPE VALUES
Symbol Meaning Value
CHAR_BIT Bits per char 8
CHAR_MAX Max. value of a char 127
CHAR_MIN Min. value of a char -128
SCHAR_MAX Max. value of a signed char 127
SCHAR_MIN Min. value of a signed char -128
UCHAR_MAX Max. value of an unsigned char 255
SHRT_MAX Max. value of a short 32767
SHRT_MIN Min. value of a short -32768
USHRT_MAX Max. value of an unsigned short 65535
INT_MAX Max. value of an int 32767
INT_MIN Min. value of a int -32768
UINT_MAX Max. value of an unsigned int 65535
SHRTLONG_MAX Max. value of a short long 8388607
SHRTLONG_MIN Min. value of a short long -8388608
USHRTLONG_MAX Max. value of an unsigned short long 16777215
LONG_MAX Max. value of a long 2147483647
LONG_MIN Min. value of a long -2147483648
ULONG_MAX Max. value of an unsigned long 4294967295
LLONG_MAX Max. value of a long long 2147483647
LLONG_MIN Min. value of a long long -2147483648
ULLONG_MAX Max. value of an unsigned long long 4294967295