AnsweredAssumed Answered

M24SR64 Page Size and Write Issues

Question asked by roberson.derek on Feb 18, 2014
I am having a problem similar to Eyal in his thread post "Write time?" with a M24SR64 using I2C. The UpdateBinary command doesn't specify the need for a page size and states that you can write 246 bytes. When writing more than seven bytes consecutively within a single command, I continuously receive the Frame Waiting eXtension response (0xF2) with a wait time of  2 * 9.6 ms. Even after waiting 30 ms, I still receive the same Frame Waiting eXtension response with the same wait time. I even tried writing 7, 6, and 4 bytes at a time yet I am still receiving the WTX response after 8 - 20 bytes have been successfully written (varies). Is there a specific page size for this device that we must adhere to?


Update: I can successfully write any amount of data to the tag 1 byte at a time, but this is resource intensive.

Update 2: After reading the response from ST in the thread "write time?" it looks like I have to accept the frame waiting extension by sending the same command back to the tag (F2020A72 ). I will confirm this when I get a chance to test it out.

Update 3: (Solution) In reference to "Update 2" above, it is correct that you must send the same frame waiting extension command back to the NFC tag to acknowledge it and then check the response, which should be 0x90 0x00. I finally found this documented in the datasheet on page 35 in the Note under Table 21. This is indeed the solution as I have verified it myself.