User manual

mikroPascal PRO for dsPIC30/33 and PIC24
MikroElektronika
232
asm
MOV _myvar, w0 ; move myvar to W0
nop
MOV #6, W0 ; move literal 6 to W0
MOV W0, _myvar ; move contents of W0 to myvar
MOV #lo_addr(_myvar), w1 ; retrieve low address word of _myvar and move it to W1
(0x2678 -> W1)
MOV #hi_addr(_myvar), W1 ; retrieve high address word of _myvar and move it to W1
(0x0000 -> W1)
MOV #lo_addr(_proc), W0 ; retrieve hi address byte of routine proc and move it to
W0 (0x0001 -> W1)
MOV #lo_addr(_msg), W0 ; retrieve low address word of constant msg and move it to
W0 (0x3652 -> W1)
MOV _myvar1+2, w0 ; accessing hi word of myvar1 variable and move it to W1 (0xABCD
-> W1)
end;
end.
Asm code and SSA optimization
If asm code is mixed with the Pascal code, keep in mind that the generated code can substantially differ when SSA
optimization option is enabled or disabled.
This is due to the fact that SSA optimization uses certain working registers to store routine parameters (W10-W13),
rather than storing them onto the function frame.
Because of this, user must be very careful when writing asm code as existing values in the working registers used by
SSA optimization can be overwritten.
To avoid this, it is recommended that user includes desired asm code in a separate routine.
With Statement
The With statement is a convenient method for referencing elements of a complex variable, such as a record.
It simplies the code by removing the need to prex each referenced element with the complex variable name; i.e.
accessing all of the record’s elds with only one reference.
Example:
program With_Test;
type Circle_Parameters =
Record
x_center : integer;
y_center : integer;
radius : integer;
end;
var Circle : Circle_Parameters;
begin
With Circle do