1、用单片机实现对SST39VF040的操作AT89C51对SST 之FLASH的编程操作详述Flash又名闪存,属于EEPROM,即电可擦除可编程的存储器。由于具有电可擦除的特性,并且其数据可保留上百年,所以它的应用范围非常广泛。非常适用于作为MicroChip以及DSP的外部程序存储器,或者作为需要存储大量数据的外部EEPROM。SST公司设计之39系列Multi-Purpose Flash,按照其存储的空间主要分以下几种:64K x8/128K x8/256K x8/512K x8 Byte,各自代表的芯片型号有: 39系列Flash之特性: SST39LF512/010/020/040工作
2、电压为3.0-3.6V; SST39VF512/010/020/040工作电压为2.7V3.6V;数据保留时间100年;工作电流典型值为10mA,待机电流为1uA;快速擦除芯片时间为70ms,字节编程时间为14us。对芯片有如下操作:chip Erase operation ;sector Erase operation ;byte program operation ;byte read operation ;write operation status detection 。通过软件对芯片的操作可以访问到SST 制造商的ID;以及芯片的ID,各芯片ID如下表: TABLE 1: PRODU
3、CT IDENTIFICATIONAddressDataManufacturers ID0000HBFHDevice IDSST39LF/VF512SST39LF/VF010SST39LF/VF020SST39LF/VF0400001H0001H0001H0001HD4HD5HD6HD7H注意:当通过软件访问了Product Identification后,必须采用软件命令退出该模式才能对芯片进行擦除、读写的操作.下面给出各软件操作指令的时序图:1. WE控制的字节编程时序:2.CE控制的字节编程时序图:3. 编程操作的状态检测时序图:4.WE控制的扇区擦除时序图:5. WE控制的芯片擦除时序
4、图:6. 软件访问ID的时序图:7. 退出软件访问ID&复位命令的时序图:根据上面的时序图,下面给出各种软件指令操作的流程图:1字节编程流程图: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A0A18,数据线为DQ0DQ7,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 longsfr Data
5、Out=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 A0A7sfr Address15_8=0xa0; /定义P2口接SST39VF040的地址线A8A15sbit Address16=P32; /定义P3.2接SST39VF040的地址线A16sbit Address17=P33; /定义P3.3接SST39VF040的地址线A17sbit Address18=P34; /定义P3.4接SST39VF040的地址线A18sbit Sst39vf040_Ce=P35; /定义P3.5接SST39VF
6、040的片选线线CEsbit Sst39vf040_We=P36; /定义P3.6接SST39VF040的写使能线WE sbit Sst39vf040_Oe=P37; /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1,0uchar Read_Id(uchar manfa_id,uchar devi_id) Sst39vf0
7、40_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();
8、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
9、_id=manuf_ID)&(Sst39vf040.device_id=devi_ID) return 1; else return 0;/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; Sst39vf040_We=1; Del
10、ay10us(); 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 C
11、hip_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; Address7_0=0xaa; Address15_8=0x2a; Delay10us(); Sst39vf040_We=0;
12、 DataOut=0x55; Delay10us(); Sst39vf040_We=1; Address7_0=0x55; Address15_8=0x55; Delay10us(); Sst39vf040_We=0; DataOut=0x80; Delay10us(); Sst39vf040_We=1; Delay10us(); Sst39vf040_We=0; DataOut=0xaa; Delay10us(); Sst39vf040_We=1; Address7_0=0xaa; Address15_8=0x2a; Delay10us(); Sst39vf040_We=0; DataOut
13、=0x55; Delay10us(); Sst39vf040_We=1; Address7_0=0x55; Address15_8=0x55; Delay10us(); Sst39vf040_We=0; DataOut=0x10; Delay10us(); Sst39vf040_We=1; while(!Wait_Data_Pulling();/检测FLASH编程,擦除操作过程中是否完成的函数,完成后返回值1 uchar Wait_Data_Pulling(void) uchar outdata; Sst39vf040_Ce=1; Sst39vf040_We=1; Sst39vf040_Oe=
14、1; Delay10us(); Sst39vf040_Ce=0; Sst39vf040_Oe=0; Delay10us(); DataOut=0xff; outdata=DataOut; Sst39vf040_Ce=1; Sst39vf040_Oe=1; if(outdata&0x80)=0x80) return 1; else return 0; /字节编程函数,入口参数:( byte_address:AmsA0 = A18A0 ,待写的数据:byte_data ), void We_Byte_Program(ulong byte_address,uchar byte_data) ulong
15、 temp_address; Sst39vf040_Ce=1; Sst39vf040_Oe=0; Sst39vf040_We=1; Address7_0=0x55; Address15_8=0x55; Address16=0; Address17=0; Address18=0; Sst39vf040_Ce=0; Sst39vf040_Oe=1; Sst39vf040_We=0; DataOut=0xaa; Delay10us(); Sst39vf040_We=1; Address7_0=0xaa; Address15_8=0x2a; Delay10us(); Sst39vf040_We=0;
16、DataOut=0x55; Delay10us(); Sst39vf040_We=1; Address7_0=0x55; Address15_8=0x55; Delay10us(); Sst39vf040_We=0; DataOut=0xa0; Delay10us(); Sst39vf040_We=1; temp_address=byte_address; Address7_0=temp_address&0x0000ff; temp_address=byte_address; Address15_8=(temp_address&0x00ff00)8; temp_address=byte_add
17、ress; if(temp_address&0x010000)!=0) Address16=1; else Address16=0; temp_address=byte_address; if(temp_address&0x020000)!=0) Address17=1; else Address17=0; temp_address=byte_address; if(temp_address&0x040000)!=0) Address18=1; else Address18=0; Delay10us(); Sst39vf040_We=0; DataOut=byte_data; Delay10u
18、s(); Sst39vf040_We=1; while(!Wait_Data_Pulling();/字节读函数 入口参数:待读的字节地址byte_address,返回参数值:读出的数据uchar Byte_Read(ulong byte_address) ulong temp_address; uchar temp_data; temp_address=byte_address; Sst39vf040_Ce=1; Sst39vf040_Oe=1; Sst39vf040_We=1; Address7_0=temp_address&0x000000ff; temp_address=byte_add
19、ress; Address15_8=(temp_address&0x0000ff00)8; temp_address=byte_address; if(temp_address&0x00010000)!=0) Address16=1; else Address16=0; temp_address=byte_address; if(temp_address&0x00020000)!=0) Address17=1; else Address17=0; temp_address=byte_address; if(temp_address&0x00040000)!=0) Address18=1; else Address18=0; Delay10us(); Sst39vf040_Ce=0; Sst39vf040_Oe=0; Delay10us(); DataOut=0xff; temp_data=DataOut; Sst39vf040_Ce=1; Sst39vf040_Oe=1; return temp_data;以上给出了读写SST39VF040的C51源程式,其他几个型号的FLASH读写都可以调用这些函数,只要改变入口参数即可,读者可以灵活应用。 (注:文档可能无法思考全面,请浏览后下载,供参考。可复制、编制,期待你的好评与关注!)
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