标示为J8， J13双排插针插上短路块，ISP下载线连接到学习板，下载程序CS21-4.hex，此时右边数码管开始走时，S4键为“星期”调整键，可调整最左边的定义为“星期”的数码管，S1键为“时”调整键，S2键为“分”调整键。 -Marked as J8, J13 double pin plug short-circuit block, ISP download cable connected to the study board, download the program CS21-4.hex, then start walking the right side of the digital control, S4 key for " weeks"　to adjust key, adjust the most on the left is defined as " week"　of the digital control, S1 key is " time"　to adjust key, S2 keys to " divide"　adjustment button.