write time ?

[eyals111]

Posted on February 17, 2014 at 09:54

hi , 

1.what is the page size in M24SR-16  ?  in the datasheet its declared  that    write time for page in I2C = 5ms , write time for up to 264 bytes =150ms 2.Is it normal after writing 5 bytes to the  M24SR , i am getting Frame extension of               2*9.6ms ?3.when authenticating using password in order to gain Read / Write Access , does it much    time as writing 16 bytes ? #fwi #m24sr #i2c #m24sr #ndef

[Anais GALLIGANI]

Posted on February 19, 2014 at 18:41 Hello,

°) 16 byte ,  but the M24SR is organized in file ,

So the write time is function of several parameters :

-

If we change or not the message Length (offset 00 but physically outside the user area)  (1  programming time)

-

the number N of physical  page supporting the message  ( N * programming time)

-

and FWI = 9.6 ms authorizing only 1 Prog

Thus

1)

Change P1P2 :  1 prog , No extension

02-19-2014 16:33:16         NFC SEND I-Block

                                                >>> CR95HFDLL_SENDRECV,

0300D6000002000BB889

08

                                                <<< 8008 

036A824F75

  080000

2)

Change P1P2 :  1 prog + 1 byte ,    2  Prog    ,  Extension request ->  Accept extension  , Pog OK

02-19-2014 16:37:40         NFC SEND I-Block

                                                >>> CR95HFDLL_SENDRECV,

0300D6000003000BD1F5E2

08

                                                <<< 8007

F2020A72

080000

02-19-2014 16:37:40         NFC SEND SWTX_Block

                                                >>> CR95HFDLL_SENDRECV,

F2020A72

08

                                                <<< 8008

0390002D53

080000

3)

Change  14 byte , first row (except P1P2)     1  Prog      , Pog OK

02-19-2014 16:31:51         NFC SEND I-Block

                                                >>> CR95HFDLL_SENDRECV,

0200D600020ED1011F55017777772E73742E636FCE80

08

                                                <<< 8008

026A82932F

  080000

4)

Change  2 byte , first & second row      2  Prog    ,  Extension request ->  Accept extension  , Pog OK

02-19-2014 16:40:53         NFC SEND I-Block

                                                >>> CR95HFDLL_SENDRECV,

0200D6000F02636FE1D0

08

                                                <<< 8007

F2020A72

  080000

02-19-2014 16:40:53         NFC SEND SWTX_Block

                                                >>> CR95HFDLL_SENDRECV,

F2020A72

08

                                                <<< 8008

029000F109

080000

2°)  For me the first extension occurs when programming on two page  ,

Don’t forget to respond to a Service command  “Waiting time Extensionâ€� request ie:

F2020A72

 by the same Service command ie:

F2020A72

3°) Yes this is normal , purpose to prevent from hacking by increasing the command  time ( there is none physical writing)

I hope this is clear enough, Best regards, ST NFC/RFID Dynamic support

[eyals111]

Posted on February 23, 2014 at 11:55

Thanks for the quick reply ,

1. In Scenario  1,3  the R-APDU  you got is 

036A824F75

     =>  SW1=6A  SW2=82   ,

which means   ''File or Application Not Found''  (Table 24 Datasheet) , So the Write Process Didn't Start .

2.

In Scenario 2,4 

the S-Block  you got is 

F2020A72   ,

Which is Frame Extension request from the IC.

from what understand page size is 16 Bytes , but there are few exception :1.If i change the NDEF message length bytes , it will take 1 Prog time .2.The Number of Page I am crossing during Write , Number of Page * 

Prog time

If you can clarify your reply I really appreciate.

[Anais GALLIGANI · Accepted solution]

Posted on March 05, 2014 at 11:42

Hello,

Please find here below answer to each point 1. In Scenario  1,3  the R-APDU  you got is 036A824F75     =>  SW1=6A  SW2=82   ,which means   ''File or Application Not Found''  (Table 24 Datasheet) , So the Write Process Didn't Start .

• This mean the sequence applied was not correct .

• Before to access or update a NDEF  it is need to

  • s

    elect correctly the application

  • Select correctly the file

• Then you can access the file for reading or writing

2.In Scenario 2,4 the S-Block  you got is F2020A72   , Which is Frame Extension request from the IC.

• F2 service Instruction  (waiting time extension , no DID)

• 02 WTX parameter

• 0A72   CRC

• The M24SR calculate by itself the requested time extension parameter WTX  in function of the Update request .

• In your case WTX parameter is equal to “02â€�

• The reader Must Acknowledge by sending the same service instruction thus in your case  F202  0A72

• After what the update will start .

Have a nice day, Best Regards, ST NFC/RFID Dynamic tag e2e support