send.asm

在PC机上进行的8250串口实验

data segment
dis0 db '+-----------------------------------------------------------------------+',0dh,0ah
     db '|                    Serial Test       Send Terminal                    |',0dh,0ah 
     db '|                       (Enter: Send    Esc:exit)                       |',0dh,0ah
     db '+-----------------------------------------------------------------------+',0dh,0ah,'$'
dis2 db 0dh,0ah,'Do you want to continue? (y\n)',0dh,0ah,'$'
dis3 db 0dh,0ah,'Send Successfully!',0dh,0ah,'$'
dis4 db 0dh,0ah,'Please input the data which you want to send,then press Enter to send!',0dh,0ah,'->  ','$'
send_data  db 100 dup(?)
data ends
code segment
     assume cs:code,ds:data
;------------------------------------------------------------------------------------------
main proc far
     mov ax,data
     mov ds,ax
     xor ax,ax

	 ;16色文本显示方式
     mov al,3
     mov ah,0
     int 10h 

     mov dx,offset dis0
     call disp

	 ;初始化串口
	 call initialize_serial
repeat_all:
     ;提示输入要发送的数据
	 mov dx,offset dis4
     call disp

     ;调用输入数据程序段
	 call inpute_data

	 ;调用发送数据段
	 call send
	 
	 ;显示发送成功
	 mov dx,offset dis3
     call disp

	 ;询问是否继续
	 mov dx,offset dis2
     call disp

     ;调用选择是否继续程序段
	 call inpute_yesno
exit_all:
     mov ax,4c00h
     int 21h
main endp
;---------------------------------------------------------------------------------------
initialize_serial proc near
     ;通信控制寄存器D7=1
     mov dx,03fbh
	 mov al,80h
	 out dx,al

     ;设置波特率为9600
	 mov dx,03f8h
	 mov al,0ch
	 out dx,al
	 inc dx
	 mov al,0
	 out dx,al

     ;初始化通信控制寄存器
	 mov dx,03fbh
	 mov al,0bh
	 out dx,al

     ;初始化modem控制器
	 mov dx,03fch
	 mov al,03h
	 out dx,al

     ;写中断允许寄存器
	 mov dx,03f9h
	 mov al,0
	 out dx,al
     ret
initialize_serial endp

;---------------------------------------------------------------------------------------
send proc near
     mov si,0
     mov dx,3fdh
	 lea si,send_data
waitse:
     mov al,[si] 
	 ;发送数据
	 push dx
	 mov dx,3f8h
	 out dx,al
	 pop dx
	 
	 ;以$号作为数据发送完的标志
	 cmp al,24h  
	 jz send_out
	  
	 in al,dx
	 cmp al,20h
	 jz waitse
	 
	 inc si
	 jmp waitse
send_out:
     ret
send endp

;---------------------------------------------------------------------------------------
inpute_data proc near
     mov si,0
inpute_data_again:
     mov ah,7
     int 21h
	 cmp al,1bh
     je exit_all
     cmp al,0dh
     je finish
     push ax
     mov dl,al
     mov ah,2
     int 21h
     pop ax
     mov send_data[si],al
     inc si
     jmp inpute_data_again
finish:
     mov send_data[si],24h  ;$符号
     ret
inpute_data endp
;-----------------------------------------------------------------------------------
inpute_yesno proc near
inpute_yesno_again:
     mov ah,7
     int 21h
     cmp al,79h
     je yes
     cmp al,6eh
     je no
     jmp inpute_yesno_again
yes:
     jmp repeat_all
no:
     jmp exit_all
     ret
inpute_yesno endp
;------------------------------------------------------------------------------------------
disp proc near
        mov ah,9
        int 21h
        ret
disp endp
;------------------------------------------------------------------------------------------
code ends
end main