RX95HF Datasheet, PDF (17/44 Pages) STMicroelectronics – Near field communication transceiver for tag emulation

RX95HF
Commands
5.5
Pollfield command (0x03) description
This command returns the current value of the FieldDet flag.
Table 10. POLLFIELD command description
Direction
Data
Comments
Example
Host to
RX95HF
RX95HF to
Host
03
<Len>
<Flags>
<Presc>
<Timer>
00
01
<FieldDet>
Command code
Length of data
RF field presence
(Optional):
01: Wait for RF field
appearance
00: Wait for RF field
disappearance
Timer prescaler (Optional)
Timer time-out (Optional)
Result code
Length of data
01, if FieldDet is set.
Otherwise, 00.
>>>0x0300 Check if RF Field
is ON or OFF
>>> 0x0303010FFF - Wait for RF
Field appearance for (16*256)/13.56 μs
Flags, Presc and Timer parameters
are optional. They must be specidfied if
the application has to wait for RF field
appearance or disappearance.
The time to wait is
(Presc+1)*(Timer+1)/13.56 μs.
<<<0x0000 or 0x000100 (No RF
field detected) or 0x000101 (RF field
detected)
Function
Table 11. Response for <POLLFIELD> command
Explanation
Response example
Comments
Pollfield
Response
00 01 01 or 00
Result code
Length of data field
Bits [7:1]: RFU
Bit 0: Field detected (if set)
This command returns the
current state of the RF
field.
<<<0x0000 or
0x000100 (No RF field
detected) or 0x000101
(RF field detected)
5.6
Listen command (0x05) description
In Tag Emulation mode, this command waits for a command from an external reader.
Before sending this command, the application must select a protocol.
Direction
Host to
RX95HF
RX95HF to
Host
Table 12. LISTEN command description
Data
Comments
Example
05
Command code
0x0500: Enters a Listening mode
where the RX95HF waits for a
00
Length of data
command from an external reader.
00
Result code
0x0000: No error. Confirmation that
00
Length of data
RX95HF now is in Listening mode.
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