timer_value equ 30h disp_h equ 31h disp_l equ 32h timer_cs equ 33h org 0000h ajmp main org 000bh ajmp time0 org 0030h main: acall init loop: mov a,timer_value cjne a,#60,next mov timer_value,#0 next: acall disp ajmp loop init: mov tmod,#01h mov th0,#3ch mov tl0,#0b0h setb tr0 setb