HP 48gII Graphing, 50g Graphing Example of an ARM assembly language program using the MASD compiler

Example of an ARM assembly language program using the MASD compiler

"!NO CODE !RPL	( turn		into RPL mode)
::	(	open	a	RPL	program )
TURNMENUOFF	(	remove		the	menu line )

CODE

%open an assembly program

%this program takes control of the screen and

%displays a Mandelbrot set using the standard algorithm

%ie: for each point from x=-1.5 to 0.5,

%for each point from y=-1 to 1

%if any an, n<256 in the series

%a0=x+iy (complex number), an+1=a0+an²

%has an absolute value > 2, the point is not part of the set

%the numbers are stored on 32 bits.

%the numbers are shifted by 12 bits, the lower 12 bits representing

%the decimal part of the number (in 1/4096)

SAVE				% save	the RPL pointers
INTOFF				% disable keyboard interrupts
SKUB {				% jump	over	the ARM code
*start
!ARM				% switch to		ARM mode
STMDB	sp! {R4 R5 R6 R7 R8 LP}			% save	registers in the stack
LDR R2, [R1, #2324]				% load	R2=x	(content of saturn
				% reg B, nibbles 0-7)
LDR R3, [R1, #2340]				% load	R3=y	(content of saturn
				% reg B, nibbles 0-7)
MOV R7 R2				% copy	X in	r7
MOV R8 R3				% copy	Y in	r8
MOV R6 256				% copy	256 in R6
{
MUL	R4, R2, R2			% r4= x² <<		12
MOV	R4	R4	>> 12	% r4= x²
MUL	R5, R3, R3
MOV	R5	R5	>> 12	% r5= y²
ADD	LP	R4	R5	% LP =	x² +	y²
CMP	LP	$4000		% if abs² an > 4
EXITGT				% exit
SUB	R4	R4	R5	% r4= x²-y²
MUL	R3	R2	R3	% R3= X*Y
ADD	R2	R7	R4	% r2= X + x²-y² = new x
MOV	R3	R3	>> 11	% r3= x*y*2
ADD	R3	R8	R3	% r3= Y+2*x*y = new Y
SUBS R6 R6 1				% decrement		loop counter
UPNE				% up if not		0

% we	have		looped		256 times and abs(An)<2, the point is in the set!
LDRB	R6	[R1		2408]	%	clear the flag ST0
BIC R6 R6			1
STRB	R6	[R1		2408]
LDMIA sp!			{R4 R5		R6 R7 R8 PC} %	restore all registers and return

}

% we have reached a An where abs(An)>2,the point is out of the set

The Development Library 6-39