ASCTOBCD: MOV R7,# 06H MOV R1,# 20H MOV R0,#20H ACALL ASCBCD LOOP: SJMP LOOP ASCBCD: MOV A,@R0 CLR C CJNE A,#30H,LOOP1 LOOP1: JC C, LOOP3 CJNE A,#3AH,LOOP2 LOOP2: JNC C, LOOP4 CLR C SUBB A, # 30H LOOP3: MOVX @R1,A. INC R0 INC R1 DJNZ R7,ASCBCD RET LOOP4: MOV A,#0FFH MOVX @R1,A LJMP LOOP3 RET