diff --git a/SerialFlash.c b/SerialFlash.c
index f830327..c057086 100755
--- a/SerialFlash.c
+++ b/SerialFlash.c
@@ -1720,7 +1720,7 @@ int SerialFlash_rangeProgram(struct CAddressRange *AddrRange, unsigned char *vDa
         return AT45rangeProgram(AddrRange, vData,mcode_Program, mcode_ProgramCode_4Adr, Index);
     else if(strstr(Chip_Info.Class,SUPPORT_SPANSION_S25FLxx_Large)!=NULL)
     {
-        if(g_bIsSF600==true)
+        if(g_bIsSF600[Index]==true)
             return SerialFlash_bulkPipeProgram(AddrRange, vData, PP_4ADR_256BYTE,mcode_ProgramCode_4Adr,Index);
         else
             return SerialFlash_bulkPipeProgram(AddrRange, vData, PP_4ADDR_256BYTE_12,mcode_ProgramCode_4Adr,Index);
@@ -1728,7 +1728,7 @@ int SerialFlash_rangeProgram(struct CAddressRange *AddrRange, unsigned char *vDa
     else if(strstr(Chip_Info.Class,SUPPORT_SPANSION_S70FSxx_Large)!=NULL)
     { 
 
-	if(g_bIsSF600==true)
+	if(g_bIsSF600[Index]==true)
 	{ 
             return SerialFlash_bulkPipeProgram(AddrRange, vData, PP_4ADDR_256BYTE_S70FS01GS,mcode_ProgramCode_4Adr_S70FSxxx,Index);
         }
@@ -1744,14 +1744,14 @@ int SerialFlash_rangeRead(struct CAddressRange *AddrRange, unsigned char *vData,
 
     if(strstr(Chip_Info.Class,SUPPORT_SPANSION_S25FLxx_Large)!=NULL)
     { 
-        if(g_bIsSF600==true)
-            return SerialFlash_bulkPipeRead(AddrRange, vData, BULK_4BYTE_FAST_READ,mcode_ReadCode,Index);
-        else
-            return SerialFlash_bulkPipeRead(AddrRange, vData, BULK_4BYTE_FAST_READ_MICRON,mcode_ReadCode,Index);
+        if(g_bIsSF600[Index]==true) 
+            return SerialFlash_bulkPipeRead(AddrRange, vData, BULK_4BYTE_FAST_READ,mcode_ReadCode,Index); 
+       else 
+            return SerialFlash_bulkPipeRead(AddrRange, vData, BULK_4BYTE_FAST_READ_MICRON,mcode_ReadCode,Index); 
     }
     if(strstr(Chip_Info.Class,SUPPORT_SPANSION_S70FSxx_Large)!=NULL)
     {  
-        if(g_bIsSF600==true)
+        if(g_bIsSF600[Index]==true)
             return SerialFlash_bulkPipeRead(AddrRange, vData, BULK_4BYTE_FAST_READ,mcode_ReadCode_S70FSxxx,Index);
         else
 	    return false;
@@ -2154,7 +2154,7 @@ int SerialFlash_bulkPipeRead(struct CAddressRange *AddrRange, unsigned char *vDa
     if(!SerialFlash_StartofOperation(Index)) 
 	return false;
     if(!(strstr(Chip_Info.Class,SUPPORT_NUMONYX_N25Qxxx_Large_2Die) != NULL &&
- 	strstr(Chip_Info.Class,SUPPORT_NUMONYX_N25Qxxx_Large_4Die) != NULL && g_bIsSF600==true))
+ 	strstr(Chip_Info.Class,SUPPORT_NUMONYX_N25Qxxx_Large_4Die) != NULL && g_bIsSF600[Index]==true))
 	SerialFlash_Enable4ByteAddrMode(true, Index);
 
     if(SerialFlash_EnableQuadIO(true, m_boEnReadQuadIO,Index)== SerialFlash_FALSE)
diff --git a/project.c b/project.c
index 284ac8a..f20b347 100755
--- a/project.c
+++ b/project.c
@@ -623,9 +623,19 @@ bool threadCompareFileAndChip(int Index)
     if( result && (!ValidateProgramParameters(Index)) )
         result = false;
 
-    if( result )
-    {
 
+    //refresh vcc before verify
+  //  TurnOFFVcc(Index);
+  //  Sleep(1000); 
+  //  TurnONVcc(Index);
+  //  Sleep(1000); 
+
+  //  if(IdentifyChipBeforeOperation(Index)==false) 
+//	result = false;
+
+    if( result )
+    { 
+ 
         ReadChip(DownloadAddrRange,Index);
 	
         size_t offset = min(DownloadAddrRange.length,g_ulFileSize);