用 AT89S51 单片机的定时 / 计数器 T0 产生一秒的定时时间，作为秒计数时间，当一秒产生时，秒计数加 1 ，秒计数到 60 时，自动从 0 开始。-with AT89S51 SCM timer / counter T0 produce than the regular time, seconds count as a time when a second time when, seconds count plus one, count to 60 seconds, the automatic starting from 0.