#include "typeDef.h"

#define AM_START_ADDR          0x1100000
#define AM_CHIP_HWORD_SIZE     0x100000                 /*1M HWords*/
#define AM_ADDR_UNLOCK1        0x555
#define AM_ADDR_UNLOCK2        0x2aa
#define AM_DATA_UNLOCK1        0xaaaa
#define AM_DATA_UNLOCK2        0x5555
#define AM_SETUP_WRITE         0xa0a0
#define AM_SETUP_ERASE         0x8080
#define AM_CHIP_ERASE          0x1010
#define AM_SECTOR_ERASE		   0x3030


/******************************************************
函數名稱:       amOpOverDetect()
函數功能:       采用poll方式檢測flash擦寫是否完成.
入口參數:       ptr         數據寫入地址/擦除扇區首址.
				trueData    要寫入的值.
				timeCounter 超時計數.
返 回 值:       OK		操作成功.
				ERROR	操作失敗.
備    注:       在預定時間內如果d7,d6仍不是truedata,則返回
				ERROR.
*******************************************************/    
STATUS  amOpOverDetect(UINT16 *ptr,  UINT16 trueData, int timeCounter)
{
	int timeTmp = timeCounter;
	volatile UINT16 *pFlash = ptr;
	UINT16 buf1, buf2,curTrueData;
	
	curTrueData = trueData & 0x8080;                  //先檢測d7位.
	while((*pFlash & 0x8080) != curTrueData)
	{
		if(timeTmp-- <= 0) break;
	}
	
	timeTmp = timeCounter;
	buf1 = *pFlash & 0x4040;						  //(為保險)再檢測d6位.
	while(1)
	{
		    buf2  = *pFlash & 0x4040;
		    if(buf1 == buf2) 
				break;
		    else
			    buf1 = buf2;
		    if(timeTmp-- <= 0) 
		    {
				return ERROR;
		    }
	}

	return OK;
}

/********************************************************
函數名稱:       sstWrite()
函數功能:       讀取緩沖區數據根據給定的長度寫入指定地址.
入口參數:       flashAddr    數據目標地址(flash).
				buffer       數據源地址.
				length 		 要寫入的字節數.
				
返 回 值:      	NULL		 寫失敗.
				flashPtr     flash的下一個地址.
備    注:       由于sst39vf160只能按半字(16bit)操作,所以
                如果要多次調用這個函數來寫入一個文件,則應
                每次讀取偶數個字節,以保證連續性.
*********************************************************/    

UINT16 *amWrite(UINT16 *flashAddr, UINT8 *buffer, int length)
{
	int i, cLength;
	volatile UINT16 *flashPtr;
	volatile UINT16 *gBuffer;
	
    flashPtr = flashAddr;
	cLength = (length + 1)/2;				//計算半字長度.
	gBuffer = (UINT16 *)buffer;      
	
	while (cLength > 0) 
	{
		*((volatile UINT16 *)AM_START_ADDR + AM_ADDR_UNLOCK1) = AM_DATA_UNLOCK1;          //解鎖.
		*((volatile UINT16 *)AM_START_ADDR + AM_ADDR_UNLOCK2) = AM_DATA_UNLOCK2;
    	*((volatile UINT16 *)AM_START_ADDR + AM_ADDR_UNLOCK1) = AM_SETUP_WRITE;
		*flashPtr = *gBuffer;                                                    //寫入數據.
		
		if(amOpOverDetect((UINT16 *)flashPtr, *gBuffer, 0x100000))             //檢測寫入是否成功.
		{
			//printf("warning: write flash may failed at:0x%x.\n", (int)flashPtr);
		}
		cLength--;
		flashPtr++;
		gBuffer++;
	}	
	
    flashPtr = flashAddr;
	gBuffer = (UINT16 *)buffer; 
	cLength = length/2;
	for(i=0; i<cLength; i++)			//寫入的數據全部校驗一次.
	{
	    if(*flashPtr++ != *gBuffer++)
	    {    
	        //printf("Error: write failed in SST39vf160 at 0x%x on verification.\n", (int)flashPtr);
	        return NULL;
	    }
	}
	if(length%2)
	{
	    if((*flashPtr++ & 0x00ff) != (*gBuffer++ & 0x00ff))             /*奇數長度的最后一個字節.*/
	    {
	        //printf("Error: write failed in SST39vf160 at 0x%x on verification.\n", (int)flashPtr);
	        return NULL;	    
	    }
	}
	return (UINT16 *)flashPtr;
}

/********************************************************
函數名稱:       amChipErase()
函數功能:       擦除整個flash芯片.
入口參數:       無.
				
返 回 值:      	OK		 擦除完全正確.
				ERROR    有單元不能正確擦除.
備    注:       datasheet上說典型時間為26s,實際大約15秒,
				所以盡量用amSectorErase().
*********************************************************/    
STATUS amChipErase(void)
{
    int i;
    volatile UINT16 *flashPtr = NULL;
    
	*((volatile UINT16 *)AM_START_ADDR + AM_ADDR_UNLOCK1) = AM_DATA_UNLOCK1;			//連續解鎖.
	*((volatile UINT16 *)AM_START_ADDR + AM_ADDR_UNLOCK2) = AM_DATA_UNLOCK2;
	*((volatile UINT16 *)AM_START_ADDR + AM_ADDR_UNLOCK1) = AM_SETUP_ERASE;
	*((volatile UINT16 *)AM_START_ADDR + AM_ADDR_UNLOCK1) = AM_DATA_UNLOCK1;
	*((volatile UINT16 *)AM_START_ADDR + AM_ADDR_UNLOCK2) = AM_DATA_UNLOCK2;
	*((volatile UINT16 *)AM_START_ADDR + AM_ADDR_UNLOCK1) = AM_CHIP_ERASE;			//寫入擦除命令.

	flashPtr = (volatile UINT16 *)AM_START_ADDR;			  

	if(amOpOverDetect((UINT16 *)flashPtr, 0xffff, 0x800000) != OK)
	{
		//printf("warning: Chip Erase time out!\n");	
	}	
	
	flashPtr = (volatile UINT16 *)AM_START_ADDR;			  
	for(i=0; i<AM_CHIP_HWORD_SIZE; i++,flashPtr++)  					//校驗是否全為0xffff.
	{
	   if(*flashPtr != 0xffff)
	   {
	    	//printf("Debug: Erase failed at 0x%x in SST39VF160 on verification.\n", (int)flashPtr);
		    return ERROR;
       }
	}
	return OK;
}    

/********************************************************
函數名稱:       amSectorErase()
函數功能:       擦除指定的flash扇區.
入口參數:       扇區地址.
				
返 回 值:      	OK		 擦除完全正確.
				ERROR    有單元不能正確擦除.
備    注:       
*********************************************************/    
STATUS amSectorErase(UINT16 *pSector)
{
    //int i;
    volatile UINT16 *flashPtr = pSector;
    
	*((volatile UINT16 *)AM_START_ADDR + AM_ADDR_UNLOCK1) = AM_DATA_UNLOCK1;			//連續解鎖.
	*((volatile UINT16 *)AM_START_ADDR + AM_ADDR_UNLOCK2) = AM_DATA_UNLOCK2;
	*((volatile UINT16 *)AM_START_ADDR + AM_ADDR_UNLOCK1) = AM_SETUP_ERASE;
	*((volatile UINT16 *)AM_START_ADDR + AM_ADDR_UNLOCK1) = AM_DATA_UNLOCK1;
	*((volatile UINT16 *)AM_START_ADDR + AM_ADDR_UNLOCK2) = AM_DATA_UNLOCK2;
	*flashPtr = AM_SECTOR_ERASE;			//寫入擦除命令.

	if(amOpOverDetect((UINT16 *)flashPtr, 0xffff, 0x20000) != OK)
	{
	    return ERROR;
		//printf("warning: Chip Erase time out!\n");	
	}	
	
	return OK;
}