putvectr.dsp

来自「pwm out demo」· DSP 代码 · 共 35 行

.MODULE/RAM/SEG=USER_PM1        PutVector;

{PUT_VECTOR: 	Overwrites the address contained in I4 with a JUMP to the address
              	contained in MR0.

 VERSION:    	1.0
 
 AUTHOR:      	SK Dynamics PVT. Ltd. India

 MOD/HISTORY:
 
 INPUTS:      	MR0 = desired vector
              	I4  = address where desired vector will go 

 DESTROYED:   	AX1,AY0,AR,SR }

.ENTRY        	PUT_VECTOR;

PUT_VECTOR:     AX1=IMASK; 
                IMASK=0;            {disable interrupts}
                AY0=H#F;
                AR=MR0 AND AY0;
                SR=LSHIFT AR BY 4 (LO);
                AR=SR0 OR AY0;
                PX=AR;              {now PX= 4Bits LSB of ENTRY,4Bits "1" for}
                                    {  unconditional jump}
                SR=LSHIFT MR0 BY -4 (LO);
                AY0=H#1800;         {18 for jump}
                AR=SR0 OR AY0;
                PM(I4,M4)=AR;       {replaces instruction at I4}
                IMASK=AX1;          {enable interrupts}
                RTS;
.ENDMOD;