ST25DV04K datasheet(75/200 Pages) STMICROELECTRONICS

75 / 200 page

7.4

RF protocol description

7.4.1

Protocol description

The transmission protocol (or simply “the protocol”) defines the mechanism used to exchange instructions and

data between the VCD (Vicinity Coupling Device) and the ST25DVxxx in both directions. It is based on the

concept of “VCD talks first”.

This means that a ST25DVxxx does not start transmitting unless it has received and properly decoded an

instruction sent by the VCD. The protocol is based on an exchange of:

•

a request from the VCD to the ST25DVxxx,

•

a response from the ST25DVxxx to the VCD.

Each request and each response are contained in a frame. The frame are delimited by a Start of Frame (SOF)

and End of Frame (EOF).

The protocol is bit-oriented. The number of bits transmitted in a frame is a multiple of eight (8), that is an integer

number of bytes.

A single-byte field is transmitted least significant bit (LSBit) first. A multiple-byte field is transmitted least

significant byte (LSByte) first and each byte is transmitted least significant bit (LSBit) first.

Figure 32. ST25DVxxx protocol timing

Request

frame

Request

frame

Response

frame

Response

frame

VCD

ST25DVxxx

Timing

7.4.2

ST25DVxxx states referring to RF protocol

The ST25DVxxx can be in one of four states:

•

Power-off

•

Ready

•

Quiet

•

Selected

Transitions between these states are specified in Figure 33. ST25DVxxx state transition diagram and

Table 92. ST25DVxxx response depending on Request_flags.

Power-off state

The ST25DVxxx is in the Power-off state when it does not receive enough energy from the VCD.

Ready state

The ST25DVxxx is in the Ready state when it receives enough energy from the VCD. When in the Ready state,

the ST25DVxxx answers any request where the Select_flag is not set.

ST25DV04K ST25DV16K ST25DV64K

RF protocol description

DS10925 - Rev 9

page 75/200

ST25DV04K bảng dữ liệu(PDF) 75 Page - STMicroelectronics

ST25DV04K bảng dữ liệu(HTML) 75 Page - STMicroelectronics

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

bảng dữ liệu tải về

Link URL