利用汇编语言实现串口的通讯（一）（BISO调用）
本程序是使用汇编语言通过BISO中断来实现多机间串口通讯功能，程序的简要功能有，支持串口号、波特率、奇偶检验、数据位等通讯参数的设置，可以实现两台PC机间的一发一收的功能；
本人刚学的汇编，写的不好（有点像C的风格），还望各位批评指正。
DATAS SEGMENT
;此处输入数据段代码
str5 db 0dh,0ah,'Enter your choice:','$'
strerro db 0dh,0ah,'Your choice is erro! please enter a correct choice!','$'
Str0 db 0dh,0ah,'Please input the number of the com:','$'
Str1 db 0dh,0ah,'Please input the baud rate:','$'
Str2 db 0dh,0ah,'Please input the data bits:','$'
Str3 db 0dh,0ah,'Please input the stop bit:','$'
Str4 db 0dh,0ah,'Please input the parity bit:','$'
Str6 db 0dh,0ah,'Press anykey to send to the other computer:','$'
choice0 db '1.com1 2.com2 3.com3','$'
choice1 db '1.2400bps 2.4800bps 3.9600bps' ,'$'
choice2 db '1.7bits 2.8bits ','$'
choice3 db '1.1bit 2.2bits ','$'
choice4 db '1.none 2.odd 3.evn','$'
sign db 0
ComNum dw 0
;choice db 2 dup(?)
StrEnter db 0dh,0ah,'$'
DATAS ENDS
STACKS SEGMENT
;此处输入堆栈段代码
STACKS ENDS
CODES SEGMENT
ASSUME CS:CODES,DS:DATAS,SS:STACKS
START:
MOV AX,DATAS
MOV DS,AX
call SetCom
call SetBand
call SetDaBits
call SetSpBit
call SetParBit
;初始化串口
mov ah,0
mov al,sign
mov dx,ComNum
int 14h
call SendData
jmp exit
SetCom proc
;com的菜单,
push bx
push cx
push dx
lpcom:
lea dx,Str0
mov ah,9
int 21h
lea dx,choice0
mov ah,9
int 21h
lea dx,str5
mov ah,9
int 21h
mov ah,1
int 21h
cmp al,'1'
je lpcom1
cmp al,'2'
je lpcom2
cmp al,'3'
je lpcom3
;cmp al,27
;;按下ESC则退出
;je com_exit
;显示错误，提示重新输入
lea dx,Strerro
mov ah,9
int 21h
;输入错误，重新输入
jmp lpcom
;将串口设为1
lpcom1:
;mov ah,0;初始化串口1
;mov dx,0
;int 14h;调用BISO中断
mov ComNum,0
jmp com_exit
;将串口设为2
lpcom2:
;mov ah,0;初始化串口2
;mov dx,1
;int 14h;调用BISO中断
mov ComNum,1
jmp com_exit
lpcom3:
;mov ah,0;初始化串口3
;mov dx,2
;int 14h;调用BISO中断
mov ComNum,2
com_exit:
pop dx
pop cx
pop bx
ret
SetCom endp
SetBand proc
;band的菜单
push bx
push cx
push dx
lpband:
;mov ah,7
;int 21h
lea dx,Str1
mov ah,9
int 21h
lea dx,choice1
mov ah,9
int 21h
lea dx,str5
mov ah,9
int 21h
mov ah,1
int 21h
cmp al,'1'
je lpband1
cmp al,'2'
je lpband2
cmp al,'3'
je lpband3
cmp al,27
;按下ESC则退出
je band_exit
lea dx,Strerro
mov ah,9
int 21h
;输入错误，重新输入
jmp lpband
lea dx,StrEnter
mov ah,9
int 21h
;将串口设为1
lpband1:
;mov ah,0;初始化串口1
;and al,0a0h;10100000;将波特率设为2400bps
;int 14h;调用BISO中断
and sign,0a0h;
jmp band_exit
;将串口设为2
lpband2:
;mov ah,0;初始化串口2
;and al,0c0h;11000000;将波特率设为4800bps
;int 14h;调用BISO中断
and sign,0c0h
jmp band_exit
lpband3:
;mov ah,0;初始化串口3
;mov al,0e0h;11000000;将波特率设为9600bps
;int 14h;调用BISO中断
add sign,0c0h
band_exit:
pop dx
pop cx
pop bx
ret
SetBand endp
SetDaBits proc
;com的菜单,
push bx
push cx
push dx
lpdata:
lea dx,Str2
mov ah,9
int 21h
lea dx,choice2
mov ah,9
int 21h
lea dx,str5
mov ah,9
int 21h
mov ah,1
int 21h
cmp al,'1'
je lpdata1
cmp al,'2'
je lpdata2
cmp al,27
;按下ESC则退出
je data_exit
;显示错误，提示重新输入
lea dx,Strerro
mov ah,9
int 21h
;输入错误，重新输入
jmp lpdata
lpdata1:
;mov ah,0;初始化串口1
;and al,0feh;00000010-f1100,7位数据位
;or al,02h
;int 14h;调用BISO中断
and sign,0feh
or sign,02h
jmp data_exit
lpdata2:
;mov ah,0;初始化串口2
;or al,03h;00000011,8位数据位
;int 14h;调用BISO中断
or sign,03h
jmp data_exit
data_exit:
pop dx
pop cx
pop bx
ret
SetDaBits endp
SetSpBit proc
;的菜单,
push bx
push cx
push dx
lpstop:
lea dx,Str3
mov ah,9
int 21h
lea dx,choice3
mov ah,9
int 21h
lea dx,str5
mov ah,9
int 21h
mov ah,1
int 21h
cmp al,'1'
je lpstop1
cmp al,'2'
je lpstop2
cmp al,27
;按下ESC则退出
je stop_exit
;显示错误，提示重新输入
lea dx,Strerro
mov ah,9
int 21h
;输入错误，重新输入
jmp lpstop
lpstop1:
;mov ah,0;初始化串口1
;and al,0fdh;00000010-f1011,第3位设为0
;int 14h;调用BISO中断
and sign,0fbh;
jmp stop_exit
lpstop2:
;mov ah,0;初始化串口2
;or al,02h;00000010-ff,第3位设为1
;int 14h;调用BISO中断
or sign,04h
jmp stop_exit
stop_exit:
pop dx
pop cx
pop bx
ret
SetSpBit endp
SetParBit proc
;的菜单,
push bx
push cx
push dx
lppar:
lea dx,Str4
mov ah,9
int 21h
lea dx,choice4
mov ah,9
int 21h
lea dx,str5
mov ah,9
int 21h
mov ah,1
int 21h
cmp al,'1'
je lppar1
cmp al,'2'
je lppar2
cmp al,'3'
je lppar3
cmp al,27
;按下ESC则退出
je par_exit
;显示错误，提示重新输入
lea dx,Strerro
mov ah,9
int 21h
;输入错误，重新输入
jmp lppar
lppar1:
;mov ah,0;初始化串口1
;and al,0f7h;第三位设为0
;int 14h;调用BISO中断
and sign,0f7h
jmp par_exit
lppar2:
;mov ah,0;初始化串口2
;or al,08h;第四位设为1
;and al,0efh;5设为0
;int 14h;调用BISO中断
or sign,08h
and sign,0efh
jmp par_exit
lppar3:
;mov ah,0;初始化串口2
;or al,02h;第4位设为1
;int 14h;调用BISO中断
or sign,08h
or sign,010h
par_exit:
pop dx
pop cx
pop bx
ret
SetParBit endp
SendData proc
push ax
push bx
push cx
push dx
lea dx,Str6
mov ah,9
int 21h
lpsend:
mov ah,1;从键盘的缓冲区读数据(BISO中断)
int 16h
jz lpnext
mov ah,0;读键盘输入数据(BISO中断)
int 16h
cmp al,1bh;esc
jz send_exit
mov ah,1;send data
mov dx,ComNum
int 14h
lpnext:
mov ah,3;read com state
mov dx,ComNum
int 14h
loop lpsend
mov ah,2;read from com
mov dx,ComNum
int 14h
and ah,01h
cmp ah,1
jne lpsend
;disp
mov dl,al
mov ah,2
int 21h
jmp lpsend
send_exit:
pop dx
pop cx
pop bx
pop ax
ret
SendData endp
exit:
MOV AH,4CH
INT 21H
CODES ENDS
END START