Using a Register in a DB

Question

Hi I am trying to print text in a LCD using Assembly code (KEIL), I was using db 'text here' to do this. Now I need to transform a byte in a register to the ASCII, is there a way?

In this code I am trying to transform the registers between location 20 and 29 to a LCD screen but using db and the indirect register @r0 does not transform the byte to ASCII code

    MOV 20H , #3AH   
        MOV 21H , #10H 
        MOV 22H , #08H 
        MOV 23H , #92H 
        MOV 24H , #0A4H 
        MOV 25H , #34H 
        MOV 26H , #55H 
        MOV 27H , #01H 
        MOV 28H , #0C4H 
        MOV 29H , #0B1H
Disp:   
MOV R0, #20H

MOV A, #38H     // use 2 lines and 5*7 
ACALL com    
MOV A, #0EH   //cursor blinking off 
ACALL com    
MOV A, #80H   // force cursor to first line 
ACALL com  
MOV A, #01H     //clr screen
ACALL com   
Muestreo: ACALL DEL_ROUTINE
MOV A, #01H     //clr screen
ACALL com 

MOV DPTR ,#STR
MOV A,#00H  
MOVC A,@A+DPTR    
ACALL L_D    
INC DPTR   

MOV A,#00H   
MOVC A,@A+DPTR    
ACALL L_D    
INC DPTR   
INC R0
JMP Muestreo 
  

com: ACALL DEL_ROUTINE  
MOV P1, A   
CLR P2.1   
SETB P2.2
CLR P2.2
RET    

L_D: ACALL DEL_ROUTINE  
MOV P1, A      
SETB P2.1     
SETB P2.2     
CLR P2.2     
RET       



DEL_ROUTINE: MOV R1, #0FFH  
L1: MOV R2, #0FFH   
L2: DJNZ R2, L2    
DJNZ R1, L1     
RET

STR: 
    DB @R0

END

Answer 1

If you want display some ASCII string from program memory use code like this

            MOV DPTR ,#STR ;set pointer to string
nextChar:
            MOV A,#00H  
            MOVC A,@A+DPTR ;get char from string
            jz endDisp     ;if string terminator, stop ouput
            ACALL L_D      ;disp char
            INC DPTR       ;move pointer to next char
            JMP nextChar   ;loop for all chars
endDisp:    jmp endDisp
STR:        DB "Hello",0

If you want display internal SRAM you need provide more info about data formating. It is unclear from you code.