PN7120 StartDiscovery returns DISCOVERY_ALREADY_STARTED

[timv81]

Hi all,

Right after I start a discovery, I get a weird notification.

My log:

NfcReader::Send: cmd:  \x20\x00\x01\x01
NfcReader::Receive: header  \x40\x00\x03
NfcReader::Receive: payload:  \x00\x10\x01
NfcReader::Send: cmd:  \x20\x01\x00
NfcReader::Receive: header  \x40\x01\x17
NfcReader::Receive: payload:  \x00\x03\x0e\x03\x00\x06\x00\x01\x02\x03\x81\x82\x02\xc8\x00\xff\x02\x00\x04\x05\x08\x02\x02
NfcReader::Send: cmd:  \x2f\x02\x00
NfcReader::Receive: header  \x4f\x02\x05
NfcReader::Receive: payload:  \x00\x00\x00\x7a\x5d
NfcReader::Send: cmd:  \x21\x00\x10\x05\x01\x01\x01\x02\x01\x01\x03\x01\x01\x04\x01\x02\x80\x01\x80
NfcReader::Receive: header  \x41\x00\x01
NfcReader::Receive: payload:  \x00
NfcReader::Send: cmd:  \x21\x03\x11\x08\x00\x01\x01\x01\x02\x01\x05\x01\x80\x01\x82\x01\x83\x01\x85\x01
NfcReader::Receive: header  \x60\x00\x06
NfcReader::Receive: payload:  \xa0\x00\xd7\xd4\x00\x00

The structure of the last notification is unexpected. GID and OID are 0000b which indicate CORE_RESET_NTF, but it's payload clearly belongs to the just delivered RF_DISCOVER_CMD. So I would expect RF_DISCOVER_NTF (0x61 0x30). Could somebody please explain if my iterpretation is correct?

Kind regards!

[timv81]

Hi Jimmychan,

Thank you for the clarification! Please let me follow up on my issue.

I actually ended up interpreting the bytes when I finally found the right NCI documentation (NFC Controller Interface (NCI) Technical Specification) and am glad to verify I did it right according to your message. It did not led me to a cause, but ruled out errors in my PN7120 implementation.

The cause of my unexpected core reset turned out to be an initialization thing in our python approach which led to 2 instances of the nfcreader being created simultaniously which causes the 2nd instance to CORE_RESET when starting the discovery.

Thanks again!

[jimmychan · Accepted solution]

For your information, this is the decode of your log.

could you tell me more information? so I may reproduce your issue on my board.

[NCI][COMMAND][20 00 01 01]
   CORE_RESET_CMD
      * Reset Type = Reset Configuration [0x01]

[NCI][RESPONSE][40 00 03 00 10 01]
   CORE_RESET_RSP
      * Status               = {Std} STATUS_OK [0x00]
      * NCI Version          = 1.0 [0x10]
      * Configuration Status = NCI RF Configuration has been reset [0x01]

[NCI][COMMAND][20 01 00]
   CORE_INIT_CMD

[NCI][RESPONSE][40 01 17 00 03 0e 03 00 06 00 01 02 03 81 82 02 c8 00 ff 02 00 04 05 08 02 02]
   CORE_INIT_RSP
      * Status = {Std} STATUS_OK [0x00]
      * NFCC Features = [0x03 0x0E 0x03 0x00]
         --> Discovery Configuration Mode      = NFCC can receive configurations from the DH and other NFCEEs [1]
         --> Discovery Frequency Configuration = Discovery Frequency configuration in RF_DISCOVER_CMD is supported [1]
         --> AID based Routing                 = Supported (NFCC supports 7816-4 Command parsing of SELECT command) [1]
         --> Protocol based Routing            = Supported [1]
         --> Technology based Routing          = Supported [1]
         --> Switched Off state                = Supported [1]
         --> Battery Off state                 = Supported [1]

      * Number of Supported RF Interface fields to follow = [0x06]
         --> {Std} NFCEE Direct RF Interface [0x00]
         --> {Std} Frame RF Interface [0x01]
         --> {Std} ISO-DEP RF Interface [0x02]
         --> {Std} NFC-DEP RF Interface [0x03]
         --> Proprietary [0x81]
         --> Proprietary [0x82]

      * Max Logical Connections           = 2 (Maximum number of Dynamic Logical Connections supported by the NFCC) [0x02]
      * Max Routing Table Size            = 200 (Indicates the maximum amount of data in Octets that are possible in a routing configuration) [0xC8 0x00]
      * Max Control Packet Payload Size   = 255 (Indicate the maximum payload length of a NCI Control Packet that the NFCC is able to receive) [0xFF]
      * Max Size for Large Parameters     = 2 (The maximum size in octets for the sum of the sizes of PB_H_INFO and LB_H_INFO_RESP parameter values) [0x02 0x00]
      * Manufacturer ID                   = NXP [0x04]
      * Manufacturer Specific Information = [0x05 0x08 0x02 0x02]
         --> Hardware version number = {NXP PN547-PN548}[0x05]
         --> ROM code version number = {NXP PN547-PN548}[0x08]
         --> Flash major version     = {NXP PN547-PN548}[0x02]
         --> Flash minor version     = {NXP PN547-PN548}[0x02]

[NCI][COMMAND][2f 02 00]
   SYSTEM_PROPRIETARY_ACT_CMD

[NCI][RESPONSE][4f 02 05 00 00 00 7a 5d]
   SYSTEM_PROPRIETARY_ACT_RSP
      * Status = {Std} STATUS_OK [0x00]
      * FW_Build_Number = [0x00 0x00 0x7A 0x5D]
[NCI][COMMAND][21 00 10 05 01 01 01 02 01 01 03 01 01 04 01 02 80 01 80]
   RF_DISCOVER_MAP_CMD
      * Number of Mapping Configurations = 5 [0x05]
         --> Mapping Configuration N° 1
            - RF Protocol  = {Std} PROTOCOL_T1T [0x01]
            - Mode         = the RF Interface is mapped to the RF Protocol in Poll Mode [0x01]
            - RF Interface = {Std} Frame RF Interface [0x01]

         --> Mapping Configuration N° 2
            - RF Protocol  = {Std} PROTOCOL_T2T [0x02]
            - Mode         = the RF Interface is mapped to the RF Protocol in Poll Mode [0x01]
            - RF Interface = {Std} Frame RF Interface [0x01]

         --> Mapping Configuration N° 3
            - RF Protocol  = {Std} PROTOCOL_T3T [0x03]
            - Mode         = the RF Interface is mapped to the RF Protocol in Poll Mode [0x01]
            - RF Interface = {Std} Frame RF Interface [0x01]

         --> Mapping Configuration N° 4
            - RF Protocol  = {Std} PROTOCOL_ISO_DEP [0x04]
            - Mode         = the RF Interface is mapped to the RF Protocol in Poll Mode [0x01]
            - RF Interface = {Std} ISO-DEP RF Interface [0x02]

         --> Mapping Configuration N° 5
            - RF Protocol  = {NXP PN547-PN548} MIFARE Classic [0x80]
            - Mode         = the RF Interface is mapped to the RF Protocol in Poll Mode [0x01]
            - RF Interface = {NXP PN547-PN548} TAG-CMD [0x80]

[NCI][RESPONSE][41 00 01 00]
   RF_DISCOVER_MAP_RSP
      * Status = {Std} STATUS_OK [0x00]

[NCI][COMMAND][21 03 11 08 00 01 01 01 02 01 05 01 80 01 82 01 83 01 85 01]
   RF_DISCOVER_CMD
      * Number of Configurations = 8 [0x08]
         --> Configuration N° 1
            - RF Technology and Mode = {Std} NFC_A_PASSIVE_POLL_MODE [0x00]
            - Discovery Frequency    = RF Technology and Mode will be executed in every discovery period [0x01]

         --> Configuration N° 2
            - RF Technology and Mode = {Std} NFC_B_PASSIVE_POLL_MODE [0x01]
            - Discovery Frequency    = RF Technology and Mode will be executed in every discovery period [0x01]

         --> Configuration N° 3
            - RF Technology and Mode = {Std} NFC_F_PASSIVE_POLL_MODE [0x02]
            - Discovery Frequency    = RF Technology and Mode will be executed in every discovery period [0x01]

         --> Configuration N° 4
            - RF Technology and Mode = {Std} NFC_F_ACTIVE_POLL_MODE (RFU) [0x05]
            - Discovery Frequency    = RF Technology and Mode will be executed in every discovery period [0x01]

         --> Configuration N° 5
            - RF Technology and Mode = {Std} NFC_A_PASSIVE_LISTEN_MODE [0x80]
            - Discovery Frequency    = RF Technology and Mode will be executed in every discovery period [0x01]

         --> Configuration N° 6
            - RF Technology and Mode = {Std} NFC_F_PASSIVE_LISTEN_MODE [0x82]
            - Discovery Frequency    = RF Technology and Mode will be executed in every discovery period [0x01]

         --> Configuration N° 7
            - RF Technology and Mode = {Std} NFC_A_ACTIVE_LISTEN_MODE (RFU) [0x83]
            - Discovery Frequency    = RF Technology and Mode will be executed in every discovery period [0x01]

         --> Configuration N° 8
            - RF Technology and Mode = {Std} NFC_F_ACTIVE_LISTEN_MODE (RFU) [0x85]
            - Discovery Frequency    = RF Technology and Mode will be executed in every discovery period [0x01]

[NCI][NOTIFICATION][60 00 06 a0 00 d7 d4 00 00]
   CORE_RESET_NTF
      * Reason Code                   = {NXP PN547-PN548} An assert has triggered PN547-PN548 reset/reboot [0xA0]
      * Configuration Status          = {Std} NCI RF Configuration has been kept [0x00]
      * Program counter for assertion = {NXP PN547-PN548} 0x0000D4D7 [0xD7 0xD4 0x00 0x00]