双数码管可调秒表，。由于单片机I/O资源足够，所以双数码管可接成静态显示方式，两个共阴数码管分别接在P1（秒十位）和P2（秒个位）口，它们的共阴极都接地，安排两个按键接在P3.2（十位数调整）和P3.3（个位数调整）上，为了方便计时，选用12MHz的晶体。为了达到精确计时，选用定时器方式2，每计数250重载一次，即250us，定义一整数变量计数重载次数，这样计数4000次即为一秒-Dual digital tube adjustable stopwatch. Because of single-chip I/O resources enough, so can be accessed by double-digital pipe into the static display, a total of two vaginal digital tube then separately at P1 (10 second) and P2 (second a bit) the mouth, they are the total cathode grounding, both keys then arranged at P3.2 (ten-digit adjusted) and P3.3 (single-digit adjusted) on, in order to facilitate the timing and use 12MHz crystal. In order to achieve accurate timing, selection of timer mode 2, each count of 250 heavy-duty one, that is, 250us, the definition of heavy-duty one count the number of integer variables, so that count is 4000 times a second