Example, Muldiv( ) function, Syntax – Echelon Neuron C User Manual
Page 135: Muldiv24( ) function
Neuron C Reference Guide
115
Example
msg_tag motor;
# define MOTOR_ON 0
# define ON_FULL 1
when (io_changes(switch1)to ON)
{
// Send a message to the motor
msg_out.tag = motor;
msg_out.code = MOTOR_ON;
msg_out.data[0] = ON_FULL;
msg_send();
}
muldiv( )
Function
The muldiv( ) function permits the computation of (
A
*
B
)/
C
where
A
,
B
, and
C
are
all 16-bit values, but the intermediate product of (
A
*
B
) is a 32-bit value. Thus,
the accuracy of the result is improved. There are two versions of this function:
muldiv( ) and muldivs( ). The muldiv( ) function uses unsigned arithmetic, while
the muldivs( ) function (see below) uses signed arithmetic.
See also muldiv24( ) and muldiv24s( ) for functions which use 24-bit intermediate
accuracy for faster performance.
Syntax
#include <stdlib.h>
unsigned long muldiv (unsigned long
A
, unsigned long
B
,
unsigned
long
C
);
Example
#include <stdlib.h>
unsigned long a, b, c, d;
...
void f(void)
{
d = muldiv(a, b, c); // d = (a*b)/c
}
muldiv24( )
Function
The muldiv24( ) function permits the computation of (
A
*
B
)/
C
where
A
is a 16-bit
value, and
B
and
C
are both 8-bit values, but the intermediate product of (
A
*
B
) is
a 24-bit value. Thus, the performance of the function is improved while
maintaining the accuracy of the result. There are two versions of this function:
muldiv24( ) and muldiv24s( ). The muldiv24( ) function uses unsigned
arithmetic, while the muldiv24s( ) function (see below) uses signed arithmetic.
See also muldiv( ) and muldivs( ) for functions which use 32-bit intermediate
accuracy for greater accuracy at the expense of slower performance. You can