MCS-51单片机实现时钟计时显示的基本方法(国外英语资料).docVIP

MCS-51单片机实现时钟计时显示的基本方法(国外英语资料) The basic method of MCS-51 MCU clock display First, count the initial value The key problem is the second clock timing, because the second is the minimum clock unit, but the use of MMCS-51 timer / counter for timing, even at work 1, the maximum time can only reach 131 milliseconds, still far from 1. To this end, we have realized the combining methods of hardware and software to count the seconds timing the timing timer is 125 milliseconds, so that when the overflow 8 times can get a second, and 8 count available software implementations. In order to get 125ms timing, we can use timer / counter 0 to work mode 1. When the SCM is 6MHz crystal, the initial number of design is X, then there is the following equation: (216X) * 2us = 125000us Calculated to count the initial value of X = 3036, binary representation of 0000101111001101, and sixteen decimal for 0BCDH. The timer is timed to be interrupted, so that the number of overflows (125 ms per 8 times) is interrupted by the interrupt service routine, and the seconds are timed. Through the numerical accumulation and numerical comparison in the program to achieve from seconds to minutes and from time to time Set the clock display and display buffer It is assumed that the clock time is displayed on six bit LED digital tubes (LED5 to LED0) (time, minutes, seconds, two each). For this purpose, a display buffer is set in the internal RAM, and there are 6 units (79H to 7EH), corresponding to the digital tube: LED5, 7EH, LED4, 7DH, LED3, 7CH, LED2, 79H, 7BH, LED1, 7AH, LED0, . The value of the display buffer, from left to right, when stored, minutes, seconds, and seconds. Suppose that the LED display program is already available as SMXS Comments [supporters: 0 people, opponents: 0, neutral: 0 people] check the comment information 2006-12-1 10:34:00 Linda_li Rank: Green Hornet Article: 613 Points: 1253 Circle: the circle of participation Registration: April 5, 2004 ninth floor of small and large |