【正文】 reti 。Timer1 CompareB Handler nop rjmp time1_ovf 。Timer1 Overflow Handler nop reti 。Timer0 Overflow Handler nop reti 。SPI Transfer Complete Handler nop reti 。USART RX Complete Handler nop reti 。USART UDR Empty Handler nop reti 。USART TX Complete Handler nop reti 。ADC Convwesion Complete Handler nop reti 。E2PROM Ready Handler nop reti 。Two wire Serial Interface Handler nop reti 。IRQ2 Handler nop reti 。Timer0 Compare Handler nop reti 。SPM Ready Handler nop。程序開始.org $02Areset: Ldi r16,high(RAMEND) 。設置堆棧指針高位 out sph,r16 Ldi r16,low(RAMEND) 。設置堆棧指針低位 out spl,r16。i/o初始化 LDI temp,0XFF 。 OUT ddra,temp out ddrc,temp 。a,c口輸出 clr temp out porta,temp out portc,temp sbi portc,0。中斷源初始化。T1初始化 中斷周期2ms ldi temp,0xff out tt1h,temp ldi temp,0x83 out tt1l,temp clr temp out tccr1a,temp ldi temp,0x03 。4MHz,64分頻,2ms out tccr1b,temp ldi temp,0x04 out timsk,temp ldi p_temp,0x01。初始化顯示緩沖區(qū)。初始化時鐘 clr hour clr hour1 clr minute clr minute1 clr second clr second1 seiwait: rjmp waitcb:。查表子程序，根據(jù)temp1中數(shù)字查表后在temp1中得到顯示碼。 push temp ldi zh,high(table*2) ldi zl,low(table*2) clr temp add zl,temp1 adc zh,temp lpm temp1,z pop temp Ret ser temp out ddrb,temp out portb,temp ldi temp,0x02 out mcucr,temp ldi temp,0x40 out gicr,temp out gifr,temp clr count seiMAIN:。中斷服務程序，中斷周期為2mstime1_ovf: in temp_int,sreg cli push temp_int。保存狀態(tài)寄存器。寫入T/C1初值 ldi temp_int,0xff out tt1h,temp_int ldi temp_int,0x83 out tt1l,temp_int inc flag_2ms cpi flag_2ms,5 brlo t1ovf2 。10ms跳出 clr flag_2ms inc count_10ms cpi count_10ms,100 brlo t1ovf2 。1s跳出 clr count_10ms inc second 。修改秒值 mov temp,second cpi temp,10 brlo t1ovf2 。10s跳出 clr second inc second1 。修改10秒值 mov temp,second1 cpi temp,6 。60s跳出 brlo t1ovf2 clr second1 inc minute 。修改分值 mov temp,minute cpi temp,10 brlo t1ovf2 。10m跳出 clr minute inc minute1 。修改十分值 mov temp,minute1 cpi temp,6 brlo t1ovf2 。60m跳出 clr minute1 inc hour 。修改時值 mov temp,hour cpi temp,4 brlo t1ovf2 。4h跳出 mov temp,hour1 cpi temp,2 brlo t1ovf3 clr hour1 。24h時鐘清零 clr hour rjmp t1ovf2t1ovf3: mov temp,hour 。24h cpi temp,10 brlo t1ovf2 。10h跳出 clr hour inc hour1 。修改十時值 t1ovf2:。根據(jù)當前時，分，秒修改顯示緩沖區(qū) in temp,portc ldi temp1,0x03 eor temp,temp1 out portc,temp 。。。。。。。根據(jù)當前所要顯示的位，將該位顯示緩沖區(qū)數(shù)字送入TEMP1中 mov temp1,minute。second sbic portc,0 mov temp1,minute1。second1 rcall cb out porta,temp1t1ovf1: pop temp_int out sreg,temp_int retitable:.db 0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90,0xff34