void delay_ms(uchar ntimes){ uchar t; for (t = 0; t<ntimes;t++) { TH0 = 0x3C; TL0 = 0xB0; TR0 = 1; while (!TF0); TF0 = 0; } TR0 = 0;}这段程序是否正确,实际使用时延时似乎不精确,当ntimes为40时,延时1S都不到