新唐nano100LE3BN读UID为什么都一样？

这是调用库函数：
   u32Data = FMC_ReadCID();
    printf("  Company ID ............................ [0x%08x]\n", u32Data);

    u32Data = FMC_ReadPID();
    printf("  Product ID ............................ [0x%08x]\n", u32Data);
    for (i = 0; i < 3; i++)
    {
        u32Data = FMC_ReadUID(i);
        printf("  Unique ID %d ........................... [0x%08x]\n", i, u32Data);
    }
   for (i = 0; i < 4; i++)
    {
        u32Data = FMC_ReadUCID(i);
        printf("  Unique Customer ID %d .................. [0x%08x]\n", i, u32Data);
    }

//=----------------一下是串口打印-----------------换个片子一样的----------------------------------------------------------------------------------------------------------


  Product ID ............................ [0x00110036]
  Unique ID 0 ........................... [0x001bdc62]
  Unique ID 1 ........................... [0x013a9b18]
  Unique ID 2 ........................... [0x00009b08]
  Unique Customer ID 0 .................. [0xffffffff]
  Unique Customer ID 1 .................. [0xffffffff]
  Unique Customer ID 2 .................. [0xffffffff]
  Unique Customer ID 3 .................. [0xffffffff]
  User Config 0 ......................... [0xfffffffe]
  User Config 1 ......................... [0x00016000]
  Data Flash Base Address ............... [0x00016000]