AS3955 datasheet(85/111 Pages) AMSCO

85 / 111 page

ams Datasheet

Page 85

[v1-01] 2015-Apr-29

Document Feedback

AS3955 − Application Information

Following is an example of an NDEF message with one Well

Known URL record, which carries the http://www.ams.com URL:

• In the NDEF message format, the URL above will be

represented by the bytes:

[D1 01 08 55 01 61 6D 73 2E 63 6F 6D]h

• The NDEF Message TLV will have the content: [03 0C D1 01

08 55 01 61 6D 73 2E 63 6F 6D]h; first byte is 03h – T field

value, indicating this is an NDEF Message TLV, second byte

is 0Ch saying the V field is 12 bytes long, the following 12

bytes are the V field holding the NDEF message.

The NDEF message TLV given above will fully occupy the first 3

blocks of the data area and the first two bytes of the 4th block

of the data area (each memory block is 4 bytes long).

Reading/Writing Through NFC Device

NFC devices use the T2T WRITE command to write data into a

T2T platform. The T2T WRITE command consists of 6 bytes, 1st

byte is the command code – A2h, 2nd byte is the block number

where data is to be written and the remaining 4 bytes are the

data content. When the execution of the command is

successful, the tag will return an ACK response – A0h. In case of

failure, a NACK code will be returned (see Error Handling section

of this datasheet for NACK codes).

The T2T READ command consists of 2 bytes, first byte is the

command code and is equal to 30h, second byte is the first block

number from which data will be returned. The response, when

successful, will return 4 blocks of data, each block is 4 bytes

long, so 16 bytes of data. In case of error, one byte NACK

response will be returned (see error handling section of AS3955

datasheet for NACK codes).

AS3955 has to be configured in Extended or Normal mode in

order for an NFC device to write/read NDEF data from the

EEPROM of the tag.

An NFC device has to send 4 write commands to the tag to write

the NDEF Message TLV bytes [03 0C D1 01 08 55 01 61 6D 73 2E

63 6F 6D]hex defined in the section above into blocks 04h-07h:

[A2 04 03 0C D1 01]hex

[A2 05 08 55 01 61]hex

[A2 06 6D 73 2E 63]hex

[A2 07 6F 6D 00 00]hex

The same NDEF Message TLV bytes can be obtained with a

single READ command, as the TLV occupies only 4 blocks and

the READ command returns 16 bytes. In case of longer NDEF

messages of course several READs are necessary until the

complete message has been read out.

AS3955 датащи(PDF) 85 Page - ams AG

AS3955 датащи(HTML) 85 Page - ams AG

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

датащи скачать

ссылки URL