TI NFC Write Single Block with Android NfcV (ISO 15693)

Question

I am writing and Android app to communicate with RF430FRL152H devices via ISO15693. This app attempts to duplicate an existing Qt C++ executable that uses a TRF7970A to communicate with the devices.

I am consistently unable to write a single block if the option flag is set, resulting in an android.nfc.TagLostException.

The TRF7970A executable follows the TRF7960 Evaluation Mode document, which states that Write Single Block (0x21) must have the Option flag set (0x40).

I have observed this behavior in my own app as well as example Android apps from the TI forums: https://e2e.ti.com/support/wireless_connectivity/nfc_rfid/f/667/p/469938/1688321#1688321

A 2011 post in the Android Issue Tracker mentions some problems with Android's nfcV and write blocks on common chips, including TI: https://code.google.com/p/android/issues/detail?id=15608

In my app this does prevent the android.nfc.TagLostException and no error flag is returned. However I am not observing the expected behavior later when enabling and setting the interrupt field in the Firmware General Control Register, so I am not sure this is a complete solution.

To complicate matters further, removing the option flag from the write commands in the TRF7970A executable continues to work correctly.

Is this the correct way to write a single block? Are there known problems between Android and TI devices, specifically the RF430FRL152H?

public class MainActivity extends AppCompatActivity {
    static final String LOG_TAG = MainActivity.class.getSimpleName();

    NfcAdapter mNfcAdapter;
    NfcV mNfcV;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mNfcAdapter = NfcAdapter.getDefaultAdapter(this);
    }

    private void enableForegroundDispatch() {
        PendingIntent pendingIntent = PendingIntent.getActivity(this, 0, new Intent(this, getClass()).addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP), 0);

        final IntentFilter intentFilter = new IntentFilter(NfcAdapter.ACTION_TECH_DISCOVERED);

        IntentFilter[] intentFilters = new IntentFilter[] { intentFilter };

        String[][] techListArray = new String[][] { new String[] { NfcV.class.getName() }};

        mNfcAdapter.enableForegroundDispatch(this, pendingIntent, intentFilters, techListArray);
    }

    @Override
    public void onPause() {
        super.onPause();
        mNfcAdapter.disableForegroundDispatch(this);
    }

    @Override
    public void onResume() {
        super.onResume();
        enableForegroundDispatch();
    }

    @Override
    protected void onNewIntent(Intent intent) {
        switch(intent.getAction())
        {
            case NfcAdapter.ACTION_TECH_DISCOVERED:
                onNfcTagDiscoveredAction(intent);
                break;

            default:
                break;
        }
    }

    private void onNfcTagDiscoveredAction(Intent intent) {
        if(mNfcV != null) {
            return;
        }

        Tag tag = intent.getParcelableExtra(NfcAdapter.EXTRA_TAG);

        mNfcV = NfcV.get(tag);

        AsyncTask<Void, Void, Void> asyncTask = new AsyncTask<Void, Void, Void>() {
            @Override
            protected Void doInBackground(Void... params) {
                try {
                    mNfcV.connect();

                    // TRF7970A "010C00030410002101000000" Register Write Request
                    // TRF7970A "0109000304F0000000" AGC Toggle
                    // TRF7970A "0109000304F1FF0000" AM PM Toggle
                    // TRF7970A "010B000304142401000000" ISO 15693 Inventory request
                    final byte[] INVENTORY = new byte[] { (byte) 0x24, (byte) 0x01, (byte) 0x00 };
                    byte[] inventoryResult = mNfcV.transceive(INVENTORY);

                    Log.d(LOG_TAG, "Inventory complete");

                    // TRF7970A "010C00030418002312010000"
                    final byte[] READ_MULTIPLE_BLOCK = new byte[] { (byte)0x00, (byte)0x23, (byte)0x12, (byte)0x01 };
                    byte[] readResult = mNfcV.transceive(READ_MULTIPLE_BLOCK);

                    Log.d(LOG_TAG, "Read multiple block complete, result length: " + readResult.length);

                    // TRF7970A "010F000304180221ff95fe00000000" Request mode
                    final byte[] WRITE_SINGLE_BLOCK_NO_OPTION = new byte[] { (byte)0x02, (byte)0x21, (byte)0xff, (byte)0x95, (byte)0xfe, (byte)0x00, (byte)0x00 };
                    byte[] noOptionResult = mNfcV.transceive(WRITE_SINGLE_BLOCK_NO_OPTION);

                    Log.d(LOG_TAG, "Wrote no option, result length: " + noOptionResult.length);

                    // TRF7970 "010F00030418402101010100000000" Request Mode
                    final byte[] WRITE_SINGLE_BLOCK_OPTION = new byte[] { (byte)0x40, (byte)0x21, (byte)0x01, (byte)0x01, (byte)0x01, (byte)0x00, (byte)0x00 };
                    byte[] optionResult = mNfcV.transceive(WRITE_SINGLE_BLOCK_OPTION);

                    Log.d(LOG_TAG, "Wrote with option, result length: " + optionResult.length);
                }
                catch(Exception e) {
                    Log.d(LOG_TAG, "Exception: " + e.toString());
                }
                return null;
            }

            @Override
            protected void onPostExecute(Void result)
            {
                mNfcV = null;
            }
        };
        asyncTask.execute();
    }
}