在看Flash例程中,碰到

S8 Flash_Erase_Sector(U32 far_address)
{
U16* address;

address = (U16*)far_address; // Strip page off

if( (U16)address & 0x0001 ) // Aligned word? i.e. address must be even address
{
return Flash_Odd_Access;
}
if( (U16)address % Flash_Sector_Size !=0 )
{
return Not_StartofSector_Error;
}

/* Only Block 0 can be erased */
FCNFG = 0;

FSTAT = FSTAT_ACCERR|FSTAT_PVIOL; //Clear errors

(*address) = 0xFFFF; // Dummy store to page to be erased
FCMD = ERASE;

程序未完

看到 (*address) = 0xFFFF; // Dummy store to page to be erased
这一句不是很明白，请大虾帮忙解释下在Falsh进行扇区擦除时候，在写入擦除命令前，这句程序为什么不可少，做什么的？谢谢了