记录AT24C128 eeprom的多字节读写

1. #define _EEPROM_DEBUG_LEVEL 0  

2.           

3. #if _EEPROM_DEBUG_LEVEL == 1  

4.          #defineEEPROM_DEBUG(fmt,args...) do{ \  

5.                    printf(fmt,##args);\  

6.          }while(0)  

7. #elif _EEPROM_DEBUG_LEVEL == 2  

8.          #defineEEPROM_DEBUG(fmt,args...) do{ \  

9.                    printf("%s:line:%d->",__FUNCTION__,__LINE__); \  

10.                    printf(fmt,##args);\  

11.          }while(0)  

12. #elif _EEPROM_DEBUG_LEVEL == 0  

13.          #defineEEPROM_DEBUG(fmt,args...)  

14. #else  

15.          #defineEEPROM_DEBUG(fmt,args...)  

16. #endif  

[cpp] view plain copy

1. #define AT24C128_PAGE_SIZE 64  

2. #define AT24C128_PAGE_COUNT 256  

3. #define AT24C128_BYTE_SIZE 16*1024  

4. #define AT24C128_WADDR 0xA0  

5. #define AT24C128_RADDR 0xA1  

写时序：

1. ///  

2. //// wrtie eeprom by page  

3. ////  

4. int writeE2promByPage(u32 startaddr,void* data,u32 len){  

5.       

6.     int retry=0,pageCnt =0,i=0,j=0,k =0;  

7.     u32 temp1=0,temp2=0,temp3=0,start=0,startPage;  

8.     u8 * pBuf;  

9.     pBuf = (u8*)data;  

10.     temp1 = startaddr % AT24C128_PAGE_SIZE;  

11.     temp2 = len % AT24C128_PAGE_SIZE;  

12.     temp3 = len / AT24C128_PAGE_SIZE;  

13.     startPage = startaddr / AT24C128_PAGE_SIZE;  

14.     if(temp1 ==0){  

15.         if(temp2 !=0) pageCnt = temp3 + 2;  

16.         else pageCnt = temp3 + 1;  

17.     }  

18.     else  

19.     {  

20.         if(temp2 !=0) pageCnt = temp3 + 3;  

21.         else pageCnt = temp3 + 2;  

22.     }  

23.       

24.     if(pageCnt > AT24C128_PAGE_COUNT) return -1;  

25.     EEPROM_DEBUG("pageCnt %d \r\n",pageCnt);  

26.     for(i=0;i

27.         //start signal !!!  

28.         while(SCCB_Start() ==0){  

29.             if(retry > 100) {  

30.                 EEPROM_DEBUG("start fail \r\n");  

31.                 return -1;  

32.             }  

33.             retry++;  

34.         }  

35.         if(i == 0){  

36.             start = startaddr;  

37.             temp1 = AT24C128_PAGE_SIZE - startaddr;  

38.         }  

39.         else{  

40.             start = (startPage + i) * AT24C128_PAGE_SIZE;  

41.             temp1 = AT24C128_PAGE_SIZE;  

42.         }  

43.         EEPROM_DEBUG("start:%d \r\n",start);  

44.         EEPROM_DEBUG("temp1:%d \r\n",temp1);  

45.         //write slave addr  

46.         SCCB_writeByte(AT24C128_WADDR);  

47.         if(SCCB_Wait_Ack() == 0){  

48.               EEPROM_DEBUG("write addr fail \r\n");  

49.                 SCCB_Stop();  

50.                 goto _end;  

51.         }  

52.         //write page high addr  

53.         SCCB_writeByte(start / 256 );  

54.         if(SCCB_Wait_Ack() == 0){  

55.               EEPROM_DEBUG("write high page addr fail \r\n");  

56.                 SCCB_Stop();  

57.                 goto _end;  

58.         }  

59.         //write page low addr  

60.         SCCB_writeByte(start % 256 );  

61.         if(SCCB_Wait_Ack() == 0){  

62.                 EEPROM_DEBUG("write low page addr fail \r\n");  

63.                 SCCB_Stop();  

64.                 goto _end;  

65.         }  

66.         //write date  

67.         for(j = 0; j 

68.             SCCB_writeByte(pBuf[k]);  

69.             //write operation need slave response ack  

70.             if(SCCB_Wait_Ack() == 0){  

71.                 EEPROM_DEBUG("write data fail \r\n");  

72.                 SCCB_Stop();  

73.                 goto _end;  

74.             }  

75.             else{  

76.                 k++;  

77.             }  

78.             if( k == len){  

79.                 SCCB_Stop();  

80.                 goto _end;  

81.             }  

82.         }  

83.         EEPROM_DEBUG("page %d write success \r\n",i);  

84.         //stop  

85.         SCCB_Stop();  

86.         SCCB_Delay(SCL_TIME_US);  

87.     }  

88. _end:  

89.     return k;  

90. }  

读取时序参考：

注意：Sequential read的时序图并不是完整的，根据文档描述Sequential read时序需要加上random的头！

即start -> slave waddr ->high addr -> low addr ->startagain ->slave raddr -> read n byte -> stop

注意写时候是wait ack ，需要eeprom回复！而读取的时候master只需要发送ack即可，读取的最后一个字节要发送的是noack。

1. /* 

2. *SEQUENTIAL READ,can read multi byte!!! 

3. * 

4. */  

5. int readE2promBySeq(u32 startaddr,void* data,u32 len){  

6.         int retry=0,j=0;  

7.         u8 * pBuf;  

8.         pBuf = (u8*)data;  

9.      //startc signal  

10.       SCCB_Delay(SCL_TIME_US);  

11.         while(SCCB_Start() ==0){  

12.                 if(retry > 100){   

13.                     EEPROM_DEBUG("start fail \r\n");  

14.                     return -1;  

15.                 }  

16.                 retry++;  

17.         }  

18.             //write slave w addr  

19.         SCCB_writeByte(AT24C128_WADDR);  

20.         if(SCCB_Wait_Ack() == 0){  

21.                 EEPROM_DEBUG("write slave w addr fail \r\n");  

22.                 SCCB_Stop();  

23.                 goto _end;  

24.         }  

25.         //write high addr   

26.         SCCB_writeByte(startaddr / 256 );  

27.         if(SCCB_Wait_Ack() == 0){  

28.             EEPROM_DEBUG("write h addr fail \r\n");  

29.             SCCB_Stop();  

30.             goto _end;  

31.         }  

32.         //write low addr  

33.         SCCB_writeByte(startaddr % 256 );  

34.         if(SCCB_Wait_Ack() == 0){  

35.             EEPROM_DEBUG("write l addr fail \r\n");  

36.             SCCB_Stop();  

37.             goto _end;  

38.         }  

39.         //start again  

40.         retry = 0;  

41.         while(SCCB_Start() ==0){  

42.                 if(retry > 100){   

43.                     EEPROM_DEBUG("start fail \r\n");  

44.                     return -1;  

45.                 }  

46.                 retry++;  

47.         }  

48.         //write slave read addr  

49.         SCCB_writeByte(AT24C128_RADDR);  

50.         if(SCCB_Wait_Ack() == 0){  

51.                     EEPROM_DEBUG("write r addr fail \r\n");  

52.                     SCCB_Stop();  

53.                     goto _end;  

54.         }  

55.       

56.         //read data  

57.         for(j = 0; j 

58.             pBuf[j] = SCCB_readByte();  

59.             if(j 

60.                 //read operation ,master just send ack ,no response  

61.                 SCCB_Ack();  

62.             }  

63.         }  

64.         SCCB_noAck();  

65.         SCCB_Stop();  

66. _end:  

67.     return j;  

68. }