ch18_将ascil码转化成二进制数据码.asm

51单片机基础篇 对于有一定基础的人看看 包含书中所以的源代码

     ;FUNCTION NAME: ASCII_TO_BINARY
     ;FUNCTION: CONVERT 1 BYTE ASCII CODE TO BINARY CODE
     ;ASCII CODE IN ACC
     ;RESULT IN ACC
     ;EXAMPLE: 'F6'RETURN 0F6H,'3E'RETURN 03EH
     ;
     ASCII_TO_BINARY
           	PUSH  	B
           	PUSH 	A
           	ANL  	A,#F0H
           	SWAP 	A
           	LCALL 	ASC_CONV
           	SWAP 	A
           	MOV  	B,A   			;D7-D4
           	POP  	A
           	ANL  	A,#0FH
           	LCALL 	ASC_CONV 		;D3-D0
           	ORL  	A,B
           	POP  	B
           	RET
     ;
     ASC_CONV:
           	SUBB 	A,#'9'+1 		;A=A-3AH
           	JNC  	$1 			;'9'<ACC<'F'
           	ADD  	A,#10  			;A=A-30H
           	SJMP 	$2 			;'0'<=ACC<='9'
     $1 	ADD  	A,#('9'+1-'A'+10)
     $2 	RET
     ;