#include <reg51.h>
sbit SW = P2^7
sbit ENABLE = P1^0
sbit MTR_1 = P1^1
sbit MTR_2 = P1^2
void main()
  {
  SW = 1
  ENABLE = 0
  MTR_1 = 0
  MTR_2 = 0
  while(1)
    {
      ENABLE = 1
      if(SW == 1)
        {
          MTR_0 = 1
          MTR_1 = 0
        }
      else
        {
          MTR_0 = 0
          MTR_1 = 1
        }
    }
  }