uart.s

在串口上PPP拨号上网的源程序(实现PPP协议栈)

	.module UART.C
	.area text(rom, con, rel)
	.dbfile G:\sppp\UART.C
	.dbfunc e putchar _putchar fV
;              c -> R16
	.even
_putchar::
	.dbline -1
	.dbline 6
; #include <iom128v.h>
; #define fosc 7372800 //晶振8MHZ
; #define baud 19200	 //波特率
; /*  		字符输出函数 		 */
; void putchar(unsigned char c)
; 	{	 
L2:
	.dbline 7
L3:
	.dbline 7
;      while (!(UCSR0A&(1<<UDRE0)));
	sbis 0xb,5
	rjmp L2
	.dbline 8
; 	 UDR0=c;    
	out 0xc,R16
	.dbline -2
	.dbline 9
; 	}
L1:
	.dbline 0 ; func end
	ret
	.dbsym r c 16 c
	.dbend
	.dbfunc e getchar _getchar fc
	.even
_getchar::
	.dbline -1
	.dbline 12
; /*  		字符输入函数 		 */	
; unsigned char getchar(void)
;   	{
L6:
	.dbline 13
L7:
	.dbline 13
; 	 while(!(UCSR0A& (1<<RXC0)));
	sbis 0xb,7
	rjmp L6
	.dbline 14
;      return UDR0;
	in R16,0xc
	.dbline -2
L5:
	.dbline 0 ; func end
	ret
	.dbend
	.dbfunc e puts _puts fI
;              s -> R20,R21
	.even
_puts::
	xcall push_gset1
	movw R20,R16
	.dbline -1
	.dbline 18
; 	}		
; /*			字符串输出函数	   	 */	
; int puts(char *s)
; 	{
	xjmp L11
L10:
	.dbline 20
	.dbline 21
	movw R30,R20
	ldd R16,z+0
	xcall _putchar
	.dbline 22
	subi R20,255  ; offset = 1
	sbci R21,255
	.dbline 23
L11:
	.dbline 19
; 	while (*s)
	movw R30,R20
	ldd R2,z+0
	tst R2
	brne L10
	.dbline 24
; 		{
; 		putchar(*s);
; 		s++;
; 		}
;     putchar(0x0a);//回车换行
	ldi R16,10
	xcall _putchar
	.dbline 25
; 	putchar(0x0d);
	ldi R16,13
	xcall _putchar
	.dbline 26
; 	return 1;
	ldi R16,1
	ldi R17,0
	.dbline -2
L9:
	xcall pop_gset1
	.dbline 0 ; func end
	ret
	.dbsym r s 20 pc
	.dbend
	.dbfunc e putstr _putstr fV
;              s -> R20,R21
	.even
_putstr::
	xcall push_gset1
	movw R20,R16
	.dbline -1
	.dbline 30
; 	}
; /*	 	   不含回车换行的字符串输出函数 	 */	
; void putstr(char *s)
; 	{
	xjmp L15
L14:
	.dbline 32
	.dbline 33
	movw R30,R20
	ldd R16,z+0
	xcall _putchar
	.dbline 34
	subi R20,255  ; offset = 1
	sbci R21,255
	.dbline 35
L15:
	.dbline 31
; 	while (*s)
	movw R30,R20
	ldd R2,z+0
	tst R2
	brne L14
	.dbline -2
	.dbline 36
; 		{
; 		putchar(*s);
; 		s++;
; 		}
; 	}	
L13:
	xcall pop_gset1
	.dbline 0 ; func end
	ret
	.dbsym r s 20 pc
	.dbend
	.dbfunc e uart_init _uart_init fV
	.even
_uart_init::
	.dbline -1
	.dbline 42
; /*			UART初始化				*/	
; 
; 
; 
; void uart_init(void)
; {
	.dbline 44
; 
;  UCSR0A=0x00;
	clr R2
	out 0xb,R2
	.dbline 45
;  UCSR0B=0x00;
	out 0xa,R2
	.dbline 46
;  UCSR0B=(1<<RXEN0)|(1<<TXEN0)|(1<<RXCIE0);//允许发送和接收;//允许发送和接收
	ldi R24,152
	out 0xa,R24
	.dbline 47
;  UBRR0L=(fosc/16/(baud+1))%256;
	ldi R24,23
	out 0x9,R24
	.dbline 48
;  UBRR0H=(fosc/16/(baud+1))/256;
	sts 144,R2
	.dbline 49
;  UCSR0C=(1<<UCSZ01)|(1<<UCSZ00);//8位数据+1位STOP位
	ldi R24,6
	sts 149,R24
	.dbline 50
;  SREG|=0x80;
	bset 7
	.dbline -2
	.dbline 51
; }
L17:
	.dbline 0 ; func end
	ret
	.dbend