INTRINS.H in C51

INTRINS.H: Internal functions
Function name: _crol_, _irol_, _lrol_
Prototype: unsigned char _crol_(unsigned char val,unsigned char n);
unsigned int _irol_(unsigned int val,unsigned char n);
unsigned int _lrol_(unsigned int val,unsigned char n);
Function: _crol_, _irol_, _lrol_ shift val left by n bits in bitwise form. This function
is related to the 8051 "RLA" instruction The above functions are different from the parameter type.
Example:
#include
main()
{
unsigned int y;
C-5 1 Programming 37
y=0x00ff;
y=_irol_(y,4); /*y=0x0ff0*/
}
Function name: _cror_, _iror_, _lror_
Prototype: unsigned char _cror_(unsigned char val,unsigned char n);
unsigned int _iror_(unsigned int val,unsigned char n);
unsigned int _lror_(unsigned int val,unsigned char n);
Function: _cror_, _iror_, _lror_ shift val right by n bits in bitwise form. This function
is related to the 8051 "RRA" instruction. The above functions are different from the parameter type.
Example:
#include
main()
{
unsigned int y;
y=0x0ff00;
y=_iror_(y,4); /*y=0x0ff0*/
}
Function name: _nop_
Prototype: void _nop_(void);
Function: _nop_ generates a NOP instruction, which can be used for time comparison in C programs. The C51 compiler does not generate a function call during the operation of the _nop_
function
, that is, the NOP instruction is directly executed in the program.
Example:
P()=1;
_nop_();
P()=0;
Function name: _testbit_
Prototype: bit _testbit_(bit x);
Function: _testbit_ generates a JBC instruction, which tests a bit and returns 1 when it is set, otherwise it returns 0.
If the bit is set to 1, the bit is reset to 0. The JBC instruction of 8051 is used for this purpose.
_testbit_ can only be used on directly addressable bits; its use in expressions is not allowed.

2008-02-19 08:56

_crol_ Character Rotate
Left_cror_ Character Rotate Right_irol_
Integer Rotate
Left_iror_ Integer Rotate Right_lrol_
Long Integer Rotate
Left_lror_ Long Integer Rotate Right_nop_
No Operation 8051 NOP
Instruction_testbit_ Test and Clear Bit 8051 JBC Instruction

Detailed explanation:

Function name: _crol_, _irol_, _lrol_
Prototype: unsigned char _crol_(unsigned char val,unsigned char n);
unsigned int _irol_(unsigned int val,unsigned char n);
unsigned int _lrol_(unsigned int val,unsigned char n);
Function: _crol_, _irol_, _lrol_ shift val left by n bits in bitwise form. This function
is related to the 8051 "RLA" instruction. The above functions are different from the parameter type.
Example:
#include
main()
{
unsigned int y;
C-5 1 Programming 37
y=0x00ff;
y=_irol_(y,4); /*y=0x0ff0*/
}

Function name: _cror_, _iror_, _lror_
Prototype: unsigned char _cror_(unsigned char val,unsigned char n);
unsigned int _iror_(unsigned int val,unsigned char n);
unsigned int _lror_(unsigned int val,unsigned char n);
Function: _cror_, _iror_, _lror_ shift val right by n bits in bitwise form. This function
is related to the 8051 "RRA" instruction. The above functions are different from the parameter type.
Example:
#include
main()
{
unsigned int y;
y=0x0ff00;
y=_iror_(y,4); /*y=0x0ff0*/
}

Function name: _nop_
Prototype: void _nop_(void);
Function: _nop_ generates a NOP instruction. This function can be used for time comparison in C programs. The C51 compiler
does not generate a function call during the operation of the _nop_ function, that is, the NOP instruction is directly executed in the program.
Example:
P()=1;
_nop_();
P()=0;

Function name: _testbit_
Prototype: bit _testbit_(bit x);
Function: _testbit_ generates a JBC instruction that tests a bit and returns 1 if it is set, otherwise it returns 0.
If the bit is set to 1, it resets the bit to 0. The 8051 JBC instruction is used for this purpose.
_testbit_ can only be used for directly addressable bits; it is not allowed to be used in expressions.