uart.s

AtMega169芯片连接RTC的测试程序

	.module uart.c
	.area text(rom, con, rel)
	.dbfile C:\TDdownload\zxy\169demo\169RTC\uart.c
	.dbfunc e putchar _putchar fV
;              c -> R16
	.even
_putchar::
	.dbline -1
	.dbline 7
; #include <iom169v.h>
; #include <macros.h>
; #define fosc 1000000 //晶振1MHZ
; #define baud 19200	 //波特率
; /*  		字符输出函数 		 */
; void putchar(unsigned char c)
; 	{	 
L2:
	.dbline 8
;      while (!(UCSRA&(1<<UDRE)));
L3:
	.dbline 8
	lds R2,192
	sbrs R2,5
	rjmp L2
X0:
	.dbline 9
; 	 UDR=c;    
	sts 198,R16
	.dbline -2
L1:
	.dbline 0 ; func end
	ret
	.dbsym r c 16 c
	.dbend
	.dbfunc e getchar _getchar fc
	.even
_getchar::
	.dbline -1
	.dbline 13
; 	}
; /*  		字符输入函数 		 */	
; unsigned char getchar(void)
;   	{
L6:
	.dbline 14
; 	 while(!(UCSRA&(1<<RXC)));
L7:
	.dbline 14
	lds R2,192
	sbrs R2,7
	rjmp L6
X1:
	.dbline 15
;      return UDR;
	lds R16,198
	.dbline -2
L5:
	.dbline 0 ; func end
	ret
	.dbend
	.dbfunc e puts _puts fV
;              s -> R20,R21
	.even
_puts::
	st -y,R20
	st -y,R21
	movw R20,R16
	.dbline -1
	.dbline 19
; 	}		
; /*			字符串输出函数	   	 */	
; void puts(char *s)
; 	{
	xjmp L11
L10:
	.dbline 21
; 	while (*s)
; 		{
	.dbline 22
; 		putchar(*s);
	movw R30,R20
	ldd R16,z+0
	xcall _putchar
	.dbline 23
; 		s++;
	subi R20,255  ; offset = 1
	sbci R21,255
	.dbline 24
; 		}	
L11:
	.dbline 20
	movw R30,R20
	ldd R2,z+0
	tst R2
	brne L10
X2:
	.dbline 25
;     putchar(0x0a);//回车换行
	ldi R16,10
	xcall _putchar
	.dbline 26
; 	putchar(0x0d);
	ldi R16,13
	xcall _putchar
	.dbline -2
L9:
	.dbline 0 ; func end
	ld R21,y+
	ld R20,y+
	ret
	.dbsym r s 20 pc
	.dbend
	.dbfunc e uart_init _uart_init fV
	.even
_uart_init::
	.dbline -1
	.dbline 30
; 	}
; /*			UART初始化				*/	
; void uart_init(void)
; {
	.dbline 31
;  UCSRB=(1<<RXEN)|(1<<TXEN)|(1<<RXCIE);//允许发送和接收
	ldi R24,152
	sts 193,R24
	.dbline 32
;  UBRRL=(fosc/16/(baud+1))%256;
	ldi R24,3
	sts 196,R24
	.dbline 33
;  UBRRH=(fosc/16/(baud+1))/256;
	clr R2
	sts 197,R2
	.dbline 34
;  UCSRC=(1<<UCSZ1)|(1<<UCSZ0);//8位数据+1位STOP位
	ldi R24,6
	sts 194,R24
	.dbline -2
L13:
	.dbline 0 ; func end
	ret
	.dbend
; }