我修改了read_10函数，大家觉得有没有问题

请看下面read_10函数.我的参数dCBW_DataXferLen,bCBW_LUN,XferLength有没有错误?
        同时对我的read函数有什么意见?
/*
PARA. FOR READ/WRITE/FORMAT
para[1]=feature
para[2]=Sector Count
para[3]=Sector Number(LBA 7-0)
para[4]=Cylinder Low (LBA 15-8)
para[5]=Cylinder High (LBA 23-16)
para[6]=Head          (LBA 27-24)
*/      
unsigned char CF_WRITE()
{
//下面是CBW
MassStorageCBW.dCBW_Signature=CBW_SIGNATURE;
MassStorageCBW.dCBW_Tag=0x60a624de;
MassStorageCBW.dCBW_DataXferLen=para[2]*512;
MassStorageCBW.bCBW_Flag=0x00;
MassStorageCBW.bCBW_LUN=0;
MassStorageCBW.bCBW_CDBLen=sizeof(WRITE_RBC);//0x0C
//下面是CBWCB
MassStorageCBW.cdbRBC.WRITE_RBC.OperationCode=write10;//0x2A
MassStorageCBW.cdbRBC.WRITE_RBC.VendorSpecific=0;//
MassStorageCBW.cdbRBC.WRITE_RBC.LBA.LBA_W8.LBA_3=para[6];
MassStorageCBW.cdbRBC.WRITE_RBC.LBA.LBA_W8.LBA_2=para[5];
MassStorageCBW.cdbRBC.WRITE_RBC.LBA.LBA_W8.LBA_1=para[4];
MassStorageCBW.cdbRBC.WRITE_RBC.LBA.LBA_W8.LBA_0=para[3];
MassStorageCBW.cdbRBC.WRITE_RBC.Reserved=0;
MassStorageCBW.cdbRBC.WRITE_RBC.XferLength=para[2];
MassStorageCBW.cdbRBC.WRITE_RBC.Reserved1[0]=0;
MassStorageCBW.cdbRBC.WRITE_RBC.Reserved1[1]=0;
MassStorageCBW.cdbRBC.WRITE_RBC.Reserved1[2]=0;
//三步,发CBW,发数据,接收CSW.
if(!BULK_Transfer_OUT((unsigned char *)&MassStorageCBW,sizeof(MassStorageCBW)))
return FALSE;
DelayMs(15);
if(!BULK_Transfer_OUT(BX,para[2]))
return FALSE;
//DelayMs(10);
if(!BULK_Transfer_IN((unsigned char *)&MassStorageCSW,13))
return FALSE;
return TRUE;
}

我发现错误了。
“发数据”的程序，参数para[2]应该改为512
错误程序：
if(!BULK_Transfer_OUT(BX,para[2]))
     return FALSE;
正确程序：
if(!BULK_Transfer_OUT(BX,512))
     return FALSE;