我用的方法跟microtomato说的类似，用一个字节存放循环的数，每个扫描周期加一。 问题是我测量一个脉冲的宽度，把它用计时器记录下来，在放到四个不同的字节，但是输出数字跟脉冲的宽度不是很吻合，有时差别很大。不知怎么搞得。下面是小程序： NETWORK 1 //NETWORK TITLE (single line) // //NETWORK COMMENTS // LD SM0.1 R Q0.0, 8 MOVB 16#FF, QB0 MOVB 0, VB120 MOVW +0, T0 NETWORK 2 LD I0.0 TONR T0, +10000 NETWORK 3 //NETWORK TITLE (single line) // //NETWORK COMMENTS // LDN I0.0 MOVW T0, VW100 NETWORK 4 LD SM0.0 MOVW VW100, VW106 /I +1000, VW106 NETWORK 5 LD SM0.0 MOVW VW106, AC1 *I +1000, AC1 NETWORK 6 LD SM0.0 INVW AC1 INCW AC1 +I VW100, AC1 NETWORK 7 LD SM0.0 MOVW AC1, VW108 /I +100, VW108 NETWORK 8 LD SM0.0 MOVW VW108, AC0 *I +100, AC0 NETWORK 9 LD SM0.0 -I AC0, AC1 NETWORK 10 LD SM0.0 MOVW AC1, VW110 /I +10, VW110 NETWORK 11 LD SM0.0 MOVW VW110, AC0 *I +10, AC0 NETWORK 12 LD SM0.0 MOVW AC1, VW112 -I AC0, VW112 NETWORK 13 LD SM0.0 ITB VW106, VB206 ITB VW108, VB207 ITB VW110, VB208 ITB VW112, VB209 NETWORK 14 LD SM0.0 ORB 16#E0, VB206 ORB 16#D0, VB207 ORB 16#B0, VB208 ORB 16#70, VB209 NETWORK 15 LD SM0.0 INVB VB206 INVB VB207 INVB VB208 INVB VB209 NETWORK 16 LDB> VB120, 16#03 MOVB 16#00, VB120 NETWORK 17 LDB= VB120, 0 MOVB VB206, QB0 NETWORK 18 LDB= VB120, 1 MOVB VB207, QB0 NETWORK 19 LDB= VB120, 2 MOVB VB208, QB0 NETWORK 20 LDB= VB120, 3 MOVB VB209, QB0 NETWORK 21 LD SM0.0 INCB VB120