NFC Digital Protocol - CWI

NFC-B TechnologyDataPoll and Listen ModePayload (Command or Response)EoDByte 1 Byte 2 … Byte n CRC_B1 CRC_B2Figure 17: Data and Payload Format – NFC-BRequirements 45: Data and Payload Format – NFC-B5.4.1.1 Data MUST be transmitted in frames as defined in Section 5.3.5.4.1.2 The payload MUST be followed by an EoD at the position, as indicated in Figure 17.The EoD MUST contain a CRC_B.5.4.1.3 The CRC_B MUST be calculated as defined in [ISO/IEC_13239]. The initial registercontent MUST be all ones (FFFFh). CRC_B1 is the LSB and CRC_B2 is the MSB.5.4.1.4 The NFC Forum Device MUST compare the received CRC_B with the CRC_Bcalculated according to Requirement 5.4.1.3. If different, then the NFC Forum DeviceMUST resort to exception processing with a Transmission Error.5.5 Command SetPayload exchanged between NFC Forum Devices consists of Commands and Responses.Table 21 lists the Commands that are supported by the NFC Forum Device configured for NFC-BTechnology. For each Command, the corresponding Response is indicated.Table 21: NFC-B – Command SetCommandALLB_REQ, SENSB_REQSLOT_MARKER(optional for Poll Mode)SLPB_REQResponseSENSB_RESSENSB_RESSLPB_RESNOTEThe Commands and Responses listed in Table 21 have different names in[ISO/IEC_14443]:ALLB_REQ refers to WUPB, SENSB_REQ refers to REQB, SENSB_RES refers toATQB, SLPB_REQ and SLPB_RES refer to HLTB and its Response.5.6 ALLB_REQ and SENSB_REQThe ALLB_REQ and SENSB_REQ Commands are used by an NFC Forum Device in Poll Modeto probe the Operating Field for NFC Forum Devices in Listen Mode.5.6.1 ALLB_REQ and SENSB_REQ CommandTable 22 defines the format of the ALLB_REQ and SENSB_REQ Commands.NFC Digital Protocol Page 52