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Calculate Square Roots

Find out the square root of the 16-bit number.

; +-----------------------------------------------------------------+
; | Purpose: Find out the square root of the 16-bit number          |
; | 8-Bit version by Joao Dartagnan Antunes Oliveira (04/20/1993)   |
; | 16-Bit modification by Bruno Marcio Diogo Venancio (08/10/2007) |
; | Email: bruno.marcio@bol.com.br                                  |
; | Brazil                                                     v1.1 |
; | Input: B (MSB) and A (LSB)   (binary)                           |
; | Output: A                                                       |
; | Destroy : R02,R03,R04,R05,R06,R07                               |
; |       THIS CODE CAN BE FREELY DISTRIBUTED WITHOUT CHANGES       |
; +-----------------------------------------------------------------+
; 
COUNT_L:        
EQU   
 
R02     
COUNT_H:        
EQU   
 
R03     
ACC_L:          
EQU   
 
R04     
ACC_H:          
EQU   
 
R05     

X_L:            
EQU   
 
R06     
X_H:            
EQU   
 
R07     

                
ORG   
 
#0x0000 
; 
; Test Routine
; 
LOOP:           
      
                
MOV   
 
A       
 
#0x4000 
                
MOV   
 
B       
 
#0x4000 
                
CALL  
 
SQRTBI  
 
; SQRT(40000)=200

                
SJMP  
 
$LOOP   

; 
; METHOD:
; 
; Add in one accumulator an odd number counter until it cotains a value great or
; equal than X , at this moment, the counter value divided for 2 will be SQRT(X)
; 

SQRTBI:         
      
                
MOV   
 
X_L     
 
A       
                
MOV   
 
X_H     
 
B       

                
MOV   
 
COUNT_L 
 
#0x0001 
 
; COUNTER <- 1
                
MOV   
 
COUNT_H 
 
#0x0000 

                
MOV   
 
ACC_L   
 
#0x0000 
 
; ACUMULATOR <- 0
                
MOV   
 
ACC_H   
 
#0x0000 

                
RET