fat.c

采用Atmeag162单片机来制作的U盘程序源码

#include <iom162v.h>
#include <macros.h>
#include <stdio.h>
#include <string.h>

#include "Flash.h"
#include "Fat.h"

extern unsigned char PageBuf[512];
unsigned int BPB_Local()
{
   unsigned int  BytsPerSec,RootEntCnt, FATSz16,value;
   unsigned char NumFATs;   
   ReadPage(0,0,PageBuf);
   if(PageBuf[510]!=0x55&&PageBuf[511]!=0xAA)return 16;
   BytsPerSec=PageBuf[12]*256+PageBuf[11];
   NumFATs=PageBuf[16];
   RootEntCnt=PageBuf[18]*256+PageBuf[17]; 
   FATSz16=PageBuf[23]*256+PageBuf[22]; 
   value=FATSz16*NumFATs*(BytsPerSec/512);
   value+=RootEntCnt/16;//(32/512)
   return (value+1)/32;
}