User's Manual

Table Of Contents

TRF7970A

SLOS743K –AUGUST 2011–REVISED APRIL 2014

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6.14.3.3.8 NFCID1 Number Register (0x17)

This register is used to hold the ID of the TRF7970A for use during card emulation and NFC peer-to-peer

target operations.

The procedure for writing the ID into register 0x17 is the following:

1. Write bits 5, 6, and 7 in register 0x18 to enable SDD anticollision (bit 5), and set bit 6 and 7 to select

the ID length of 4, 7, or 10 bytes.

2. Write the ID into register 0x17. This should be done using write continuous mode with 4, 7, or 10 bytes

(according to what was set in register 0x18 bits 6 and 7).

6.14.3.3.9 NFC Target Detection Level Register (0x18)

Table 6-52. NFC Target Detection Level Register (0x18)

Function: Defines level for RF wake up, enables automatic SDD and gives NFCID size. This register is supplied by Vin to ensure data

retention during complete power down.

Default: 0x00 at POR on Vin (not POR based on V

DD_X

) and not reset at EN = 0

Bit Name Function Description

NFCID1 Size

Id_s1 Id_s0

(bytes)

B7 Id_s1

0 0 4

NFCID1 size used in 106-

kbps passive target SDD 0 1 7

1 0 10

B6 Id_s0

1 1 Not allowed

Automatic SDD using internal state machine and ID stored in the NFCID1

B5 Sdd_en

Number register (0x17)

B4 N/A

Extended range for RF

B3 Hi_rf

measurements

B2 Rfdet_h2 RF field level required for Comparator output is displayed in B7 of the NFC Target Protocol register

system wakeup. If all bits (0x19)

B1 Rfdet_h1

are 0, then the RF level

B0 Rfdet_h0

detection is off.

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