Examples
Here is an example. You can find more examples on the download page. This example calculates the square root of a 32-bit integer, using a simple algoritm.; SimpleSqrt.asm
; SimpleSqrt.asm
; An example for ppmacros
;
include "p16f88.inc"
include "ppmacros.inc"
; SET TABSIZE to 16 (edit/properties/sizes)
CBLOCK 0x20
SI:4, SO:4, V1:4, Sold:4
_PPMCR1_, _PPMCR2_, _PPMCR3_
_PPMCR4_, _PPMCR5_, _PPMCR6_
_PPMCR7_, _PPMCR8_, _PPMCR9_
_PPMCR10_, _PPMCR11_, _PPMCR12_
_PPMCR13_
ENDC
;**************************************************************
;*** Begin CODE ***
;**************************************************************
org 0000h
goto main
;**************************************************************
;*** Interrupt handler ***
;**************************************************************
nop
nop
nop
retfie
main:
;**************************************************************
;*** Main program ***
;**************************************************************
load_f32_l32 SI, .1963964721
call SQRT
nop ; place breakpoint here
; check SO in watch window
; Result should be AD1C
for_f32_l32_l32 SI,.0,.4000000000
call SQRT
nop ; place breakpoint here
; check SI and SO in watch window / file register
next
lp99 nop
goto lp99
;**************************************************************
;*** Subroutines ***
;**************************************************************
; SQRT - the simple (but stupid) way.
; input: SI, output:SO, uses: V1 (32 bit)
;
; The simple sqrt algorthime does work as follow:
; Divide the number by two
; Avarage the result with '2'
; Use this number instead of the two above and repeat until the result is stable
; Examples:
; 100/2=50. (50+2)/2=26.
; 100/26=3. (26+3)/2=14.
; 100/14=7. (14+7)/2=10.
; 100/10=10. (10+10)/2=10.
;
; 120/2=60. (60+2)/2/31.
; 120/31=3. (31+3)/2=17.
; 120/17=7. (17+7)/2=12.
; 120/12=10. (12+10)/2=11.
; 120/11=10. (11+10)/2=10.
;
SQRT: if_f32_gt_l32 SI,.1
f32_f32_div_l32 SO,SI,.2 ; start value of guess is SI/2
repeat
load_f32_f32 Sold,SO
f32_f32_div_f32 V1,SI,SO ; V1 = SI/SO
f32_f32_add_f32 SO,SO,V1 ; SO = (SO + V1) /2
f32_f32_div_l32 SO,SO,.2
if_f32_eq_f32 SO,Sold
load_f32_f32 V1,SO
end_if
until_f32_eq_f32 SO,V1 ; loop is finished if SO equal to V1
else_if
load_f32_f32 SO,SI ; if <2 then output = input
end_if
return
END