User manual

mikroBasic PRO for dsPIC30/33 and PIC24
MikroElektronika
197
In the First_Module we will dene and declare routine called pi_r_squared (calculates pi multiplied by the radius
squared):
module First_Module
sub procedure pi_r_square(dim rr as oat) ‘ Declaration of the pi_r_square routine
implements
sub procedure pi_r_square(dim rr as oat) ‘ Denition of the pi_r_square routine
dim res as oat
res = rr*3.14
end sub
end.
In the Second_Module we will make a call to the routines dened externally (r_squared and pi_r_squared). First
of all, we must declare their prototypes followed with a external modier. Then, we can proceed to the routine call :
module Second_Module
sub procedure CircleArea()
sub function r_square(dim r as oat) as oat external ‘ Declaration of the r_square
routine (dened in Main_Module) followed with a external modier
sub procedure pi_r_square(dim rr as oat) external ‘ Declaration of the pi_r_square
routine (dened in Second_Module) followed with a external modier
implements
sub procedure CircleArea() ‘ Denition of the CircleArea routine
dim res as real
res = r_square(5) ‘ Calculate r*r
pi_r_square(res) ‘ Calculate pi*r*r
end sub
end.
Variables and dsPIC30/33 and PIC24
Every declared variable consumes part of RAM memory. Data type of variable determines not only the allowed range
of values, but also the space a variable occupies in RAM memory. Bear in mind that operations using different types
of variables take different time to be completed. mikroBasic PRO for dsPIC30/33 and PIC24 recycles local variable
memory space – local variables declared in different functions and procedures share the same memory space, if
possible.
There is no need to declare SFRs explicitly, as mikroBasic PRO for dsPIC30/33 and PIC24 automatically declares
relevant registers as global variables of word. For example: W0, TMR1, etc.