用单片机实现对SST39VF040的操作(2)

2．读取ID流程图：

3．复位命令流程图：

4．芯片擦除命令流程图：

5．扇区擦除命令流程图：

下面以SST39VF040为列，给出AT89C51对其做编程动作的source code：

SST39VF040地址线为A0…A18，数据线为DQ0…DQ7，片选线CE，数据写使能线WE，数据读使能线OE。

#define uchar unsigned char #define uint unsigned int #define ulong unsigned long

sfr DataOut=0x80; //定义P0口接SST39VF040的数据线 sfr Address7_0=0x90; //定义P1口接SST39VF040的地址线 A0…A7 sfr Address15_8=0xa0; //定义P2口接SST39VF040的地址线A8…A15 sbit Address16=P3^2; //定义P3.2接SST39VF040的地址线A16 sbit Address17=P3^3; //定义P3.3接SST39VF040的地址线A17 sbit Address18=P3^4; //定义P3.4接SST39VF040的地址线A18

sbit Sst39vf040_Ce=P3^5; //定义P3.5接SST39VF040的片选线线CE sbit Sst39vf040_We=P3^6; //定义P3.6接SST39VF040的写使能线WE sbit Sst39vf040_Oe=P3^7; //定义P3.7接SST39VF040的读使能线OE struct Flash {

uchar manufacturer_id; uchar device_id; ulong address; } Sst39vf040;

//读FLASH ID的函数，入口参数：FLASH的manfacturer_ID，device_ID，出口参数返回1，0 uchar Read_Id(uchar manfa_id,uchar devi_id) {

Sst39vf040_Ce=1; Sst39vf040_We=1; Address7_0=0x55;

Address15_8=0x55; Sst39vf040_Oe=1; Sst39vf040_Ce=0; Sst39vf040_We=0; DataOut=0xaa; Sst39vf040_We=1; Address7_0=0xaa; Address15_8=0x2a;

Delay10us();

Sst39vf040_We=0; DataOut=0x55;

Delay10us(); Sst39vf040_We=1; Address7_0=0x55; Address15_8=0x55; Delay10us(); Sst39vf040_We=0; DataOut=0x90; Sst39vf040_We=1; Sst39vf040_Ce=1; Delay10us(); Address7_0=0x00; Address15_8=0x00; Sst39vf040_Ce=0; Sst39vf040_Oe=0; DataOut=0xff;

Sst39vf040.manufacturer_id=DataOut; Address7_0=0x01; Delay10us();

Sst39vf040.device_id=DataOut; Sst39vf040_Ce=1;

if((Sst39vf040.manufacturer_id==manuf_ID)&&(Sst39vf040.device_id==devi_ID)) }

//退出读ID的状态以及命令FLASH复位的函数 void Read_Id_Exit(void) {

Sst39vf040_Ce=1; Sst39vf040_Oe=0; Sst39vf040_We=1; Address7_0=0x55; Address15_8=0x55; Sst39vf040_Ce=0; Sst39vf040_Oe=1; Sst39vf040_We=0; Delay10us(); DataOut=0xaa;

else

return 0; return 1;

Sst39vf040_We=1; Delay10us(); Address7_0=0xaa; Address15_8=0x2a; Delay10us(); Sst39vf040_We=0; Delay10us(); DataOut=0x55; Sst39vf040_We=1; Delay10us(); Address7_0=0x55; Address15_8=0x55; Delay10us(); Sst39vf040_We=0; Delay10us(); DataOut=0xf0; Sst39vf040_We=1; Sst39vf040_Ce=1; Delay10us(); Sst39vf040_Ce=0; }

//芯片擦除函数 void Chip_Erase(void) {

Sst39vf040_Ce=1; Sst39vf040_Oe=0; Sst39vf040_We=1; Address18=0; Address17=0; Address16=0; Address7_0=0x55; Address15_8=0x55; Sst39vf040_Ce=0; Sst39vf040_Oe=1; Sst39vf040_We=0; DataOut=0xaa; Delay10us(); Sst39vf040_We=1;