ST AN3955 APPLICATION NOTE

AN3955

Application note

CR95HF library for ISO/IEC 14443-3 and SRIX contactless tag ICs

1 Introduction

This document describes the ISO/IEC 14443-3 libraries used by a microcontroller to drive
the CR95HF 13.56 MHz multiprotocol contactless transceiver using an SPI or UART
interface in order to perform wireless communications with ISO/IEC 14443 Type A or B
contactless tag.

The library was developed to speed up the development of applications using the CR95HF.
The CR95HF library is composed of three layers:

■ CR95HF low level layer

■ Standard ISO/IEC 14443-3 protocol layer (type A and type B)

■ SRIX4K product specific layer

The library code has been developed in ANSI C language, and validated on an STM32
evaluation board.

1.1 Reference documents

■ CR95HF datasheet

■ ISO/IEC 14443-3 specification

■ SRIX4K datasheet

September 2011 Doc ID 022017 Rev 1 1/68

www.st.com

Contents AN3955

Contents

1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

1.1 Reference documents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

2 Acronyms and notational conventions . . . . . . . . . . . . . . . . . . . . . . . . . . 9

2.1 List of terms and acronyms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

2.2 Notational conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

2.2.1 Binary number representation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

2.2.2 Hexadecimal number representation . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

2.2.3 Decimal number representation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

3 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

3.1 CR95HF overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

3.2 ISO/IEC 14443-3 overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

3.3 SRIX4K product overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

3.4 Library overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

4 CR95HF low level layer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

4.1 Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

4.2 Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

4.3 CR95HF layer functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

4.4 IDN function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

4.5 ECHO function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

4.6 ProtocolSelect function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

4.7 SendRecv function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

4.8 Idle function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

4.9 RdReg function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

4.10 BaudRate function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

4.11 SendEOF function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

4.12 FieldOff function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

4.13 HexCommandToStringCommand function . . . . . . . . . . . . . . . . . . . . . . . . 22

4.14 IsReaderResultCodeOk function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

4.15 IsReaderErrorCode function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

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4.16 IsCommandExists function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

4.17 GetReaderErrorCode function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

4.18 Application example: protocol selection and communication . . . . . . . . . . 25

5 ISO/IEC 14443-3 layers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

5.1 ISO/IEC 14443-3 Type A layer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

5.1.1 ISO/IEC 14443-3 Type A command format . . . . . . . . . . . . . . . . . . . . . . 26

5.1.2 EOF and SOF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

5.1.3 Parity bit management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

5.1.4 ISO/IEC 14443-3 Type A CRC16 management . . . . . . . . . . . . . . . . . . . 27

5.1.5 Functions of ISO/IEC 14443_A layer . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

5.1.6 CR95HF configuration function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

5.1.7 ISO/IEC 14443-3 Type A command function . . . . . . . . . . . . . . . . . . . . . 30

5.1.8 ISO/IEC 14443-3 Type A Split function . . . . . . . . . . . . . . . . . . . . . . . . . 33

5.1.9 ISO/IEC 14443-3 Type A Is function . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

5.1.10 ISO/IEC 14443-3 Type A GET functions . . . . . . . . . . . . . . . . . . . . . . . . 36

5.1.11 ISO/IEC 14443-3 Type A Advanced functions . . . . . . . . . . . . . . . . . . . . 37

5.2 ISO/IEC 14443-3 Type B layer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

5.2.1 ISO/IEC 14443-3 Type B command format . . . . . . . . . . . . . . . . . . . . . . 40

5.2.2 EOF and SOF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

5.2.3 Data management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

5.2.4 ISO/IEC 14443-3 Type B CRC16 management . . . . . . . . . . . . . . . . . . . 40

5.2.5 Functions of ISO/IEC 14443-3 Type B layer . . . . . . . . . . . . . . . . . . . . . 40

5.2.6 CR95HF configuration function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

5.2.7 ISO/IEC 14443-3 Type B Set function . . . . . . . . . . . . . . . . . . . . . . . . . . 42

5.2.8 ISO/IEC 14443-3 Type B command function . . . . . . . . . . . . . . . . . . . . . 43

5.2.9 ISO/IEC 14443-3 Type B Split function . . . . . . . . . . . . . . . . . . . . . . . . . 45

5.2.10 ISO/IEC 14443-3 Type B Is function . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

6 SRIX4K library . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

6.1 SRIX4K command format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

6.1.1 SRIX4K CR16 management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

6.1.2 Functions of SRIX4K layer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

6.1.3 CR95HF configuration function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

6.1.4 SRIX4K command function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

6.1.5 SRIX4K Split functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

6.1.6 SRIX4K Is function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

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Contents AN3955

6.1.7 SRIX4K Advanced function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

7 Project example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

7.1 Hardware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

7.2 Keil µvision

7.3 Project structure on Keil µvision

7.3.1 Standard peripheral drivers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

7.3.2 Drivers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

7.3.3 Libraries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

® . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

® . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

7.4 Application functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

7.4.1 Application example flowchart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

7.4.2 Detect an ISO/IEC 14443-3 Type A tag function . . . . . . . . . . . . . . . . . . 64

7.4.3 Detect an ISO/IEC 14443-3 Type B tag function . . . . . . . . . . . . . . . . . . 65

7.4.4 Detect an SRIX tag function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

8 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

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AN3955 List of figures

List of figures

Figure 1. Typical application block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Figure 2. Interaction between typical user application and CR95HF library layers . . . . . . . . . . . . . . 12

Figure 3. Example of function flowchart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Figure 4. Select sequence algorithm flowchart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Figure 5. Example of project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

Figure 6. Flowchart of application example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

Figure 7. Flowchart of User detects an ISO/IEC 14443-3 Type A tag . . . . . . . . . . . . . . . . . . . . . . . . 64

Figure 8. Flowchart of User detects an ISO/IEC 14443-3 Type B tag . . . . . . . . . . . . . . . . . . . . . . . . 65

Figure 9. SRIX tag detection flowchart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66

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List of tables AN3955

List of tables

Table 1. Terms and acronyms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Table 2. CR95HF layer functions based on CR95HF commands . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Table 3. CR95HF layer additional functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Table 4. CR95HF_IDN function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Table 5. CR95HF_Echo function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Table 6. CR95HF_ProtocolSelect function description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Table 7. CR95HF_ProtocolSelect ISO/IEC 14443-3 Type A protocol parameter. . . . . . . . . . . . . . . 17

Table 8. CR95HF_ProtocolSelect ISO14443-3 Type B protocol parameter. . . . . . . . . . . . . . . . . . . 17

Table 9. CR95HF_SendRecv function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Table 10. SendRecv command in ISO/IEC 14443-3 Type A case . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Table 11. SendRecv command in ISO/IEC 14443-3 Type B case . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Table 12. CR95HF success response value for ISO/IEC 14443-3 Type A. . . . . . . . . . . . . . . . . . . . . 19

Table 13. Specific success code for ACK or NAK contactless response . . . . . . . . . . . . . . . . . . . . . . 20

Table 14. CR95HF success response value for ISO/IEC 14443-3 Type B. . . . . . . . . . . . . . . . . . . . . 20

Table 15. CR95HF error response value for ISO/IEC 14443-3 Type A and B . . . . . . . . . . . . . . . . . . 20

Table 16. CR95HF_Idle function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Table 17. CR95HF_RdReg function description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Table 18. CR95HF_BaudRate function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Table 19. CR95HF_SendEOF function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Table 20. CR95HF_FieldOff function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Table 21. CR95HF_HexCommandToStringCommand function description. . . . . . . . . . . . . . . . . . . . 22

Table 22. CR95HF_IsReaderResultCodeOk function description . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Table 23. CR95HF_IsReaderErrorCode function description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Table 24. CR95HF_IsCommandExists function description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Table 25. CR95HF_GetReaderErrorCode function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Table 26. ISO/IEC 14443-3 Type A commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Table 27. Configuration of the CR95HF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Table 28. ISO/IEC 14443-3 Type A layer function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Table 29. ISO14443A_ProtocolSelect function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Table 30. ISO/IEC 14443-3 Type A Is function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Table 31. ISO/IEC 14443-3 Type A GET function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Table 32. ISO/IEC 14443-3 Type A Advanced function description . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Table 33. ISO14443A_ProtocolSelect function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Table 34. ISO14443A_REQA function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Table 35. ISO14443A_WUPA function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Table 36. ISO14443A_HLTA function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Table 37. ISO14443A_AnticollisionLevel1 function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Table 38. ISO14443A_AnticollisionLevel2 function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Table 39. ISO14443A_AnticollisionLevel3 function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Table 40. ISO14443A_SelectLevel1 function description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Table 41. ISO14443A_SelectLevel2 functiond description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Table 42. ISO14443A_SelectLevel3 function description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Table 43. ISO14443A_Split ATQA function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Table 44. ISO14443A_IsCollisionDetected function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Table 45. ISO14443A_IsCRCError function description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Table 46. ISO14443A_IsParityError function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Table 47. ISO14443A_Is14443_4Compatible function description . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Table 48. ISO14443A_IsUIDComplete function description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

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Table 49. ISO14443A_IsPresent function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Table 50. ISO14443A_IsCorrectBCC function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Table 51. ISO14443A_GetSignificantBit function description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Table 52. ISO14443A_GetFirstCollisionByte function description . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Table 53. ISO14443A_GetFirstCollisionBit function description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Table 54. ISO14443A_SelectSequence function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Table 55. ISO14443A_GetUIDsize function description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Table 56. ISO14443A_GetUID function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Table 57. ISO/IEC14443-3 Type B configuration function description . . . . . . . . . . . . . . . . . . . . . . . . 40

Table 58. ISO14443B_SetParamByte function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Table 59. ISO/IEC 14443-3 Type B command functions description . . . . . . . . . . . . . . . . . . . . . . . . . 41

Table 60. ISO/IEC 14443-3 Type B Split functions description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Table 61. ISO/IEC 14443-3 Type B Is function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Table 62. ISO14443B_ProtocolSelect function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

Table 63. ISO14443B_SetParamByte function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

Table 64. ISO14443B_REQB function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Table 65. ISO14443B_WUPB function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Table 66. ISO14443B_SlotMarker function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Table 67. ISO14443B_Attrib function description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

Table 68. ISO14443B_HLTB function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

Table 69. ISO14443B_SplitATQB function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

Table 70. ISO14443B_SplitApplicationDataField function description . . . . . . . . . . . . . . . . . . . . . . . . 45

Table 71. ISO14443B_SplitProtocolInfoField function description . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

Table 72. ISO14443B_IsPresent function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

Table 73. SRIX4K_ProtocolSelect function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

Table 74. Commands included in the lib_SRIX4k.c file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

Table 75. SRIX4K Split functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

Table 76. SRIX4K_Is functions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

Table 77. SRIX4K_Advanced functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

Table 78. SRIX4K_ProtocolSelect function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

Table 79. SRIX4K_Initiate function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

Table 80. SRIX4K_Pcall16 function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

Table 81. SRIX4K_SlotMarker function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

Table 82. SRIX4K_SelectChipID command description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

Table 83. SRIX4K_Completion function description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

Table 84. SRIX4K_ResetToInventory command description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

Table 85. SRIX4K_ReadSingleBlock function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

Table 86. SRIX4K_WriteSingleBlock function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

Table 87. SRIX4K_GetUID function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

Table 88. SRIX4K_SplitInitiateResponse function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

Table 89. SRIX4K_SplitPCall16Response function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

Table 90. SRIX4K_SplitSlotMarkerResponse function description. . . . . . . . . . . . . . . . . . . . . . . . . . . 55

Table 91. SRIX4K_SplitSelectChipIDResponse function description. . . . . . . . . . . . . . . . . . . . . . . . . 55

Table 92. SRIX4K_SplitCompletionResponse function description . . . . . . . . . . . . . . . . . . . . . . . . . . 56

Table 93. SRIX4K_SplitReadSingleBlockResponse function description. . . . . . . . . . . . . . . . . . . . . . 56

Table 94. SRIX4K_SplitWritedBlockResponse function description. . . . . . . . . . . . . . . . . . . . . . . . . . 57

Table 95. SRIX4K_SplitGetUIDResponse function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

Table 96. SRIX4K_IsPresent function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

Table 97. SRIX4K_IsSRIX4KPresent function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

Table 98. SRIX4K_GetUIDadvanced function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

Table 99. SRIX4K_GetChipIDAndSelectIt function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

Table 100. SRIX4K_Anticollision function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

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List of tables AN3955

Table 101. Detection of an ISO/IEC 14443-3 Type A contactless tag . . . . . . . . . . . . . . . . . . . . . . . . . 64

Table 102. Detection of an SRIX tag function. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

Table 103. Document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

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AN3955 Acronyms and notational conventions

2 Acronyms and notational conventions

2.1 List of terms and acronyms

Table 1. Terms and acronyms

Terms Definition

AFI Application Family Identifier

ATQA Answer to Request Type A

ATQB Answer to Request Type B

ATS Answ e r To Select

CRC Cyclic Redundancy Check

EOF End Of Frame

FWT Frame Waiting Time

HLTA Halt command Type A

HLTB Halt command Type B

IC Integrated Circuit

IEC International Electrotechnical Commission

ISO International Organization for Standardization

MCU Microcontroller Unit

NACK Negative Acknowledge

NFC Near Field Communication

RATS Request for Answer To Select

REQA Request command Type A

REQB Request command Type B

RF Radio Frequency

RFID Radio Frequency Identification

RFU Reserved for Future Use

SAK Select AcKnowledge

SOF Start Of Frame

SRI Short Range Interface

SRIX Short Range Interface with anti clone function

UID Unique Identifier

WUPA Wake-Up A command Type A

WUPB Wake-Up A command Type B

XOR eXclusif OR

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Acronyms and notational conventions AN3955

2.2 Notational conventions

The following conventions and notations apply in this document unless otherwise stated.

2.2.1 Binary number representation

Binary numbers are represented by strings of digits 0 and 1 shown with the Most Significant
Bit (MSB) on the left, the Least Signifcant Bit (LSB) on the right, and “0b” added at the
beginning.

For example: 0b11110101

2.2.2 Hexadecimal number representation

Hexadecimal numbers are represented by using the numbers 0 to 9, the characters A - F,
and a “0x” added at the beginning. The Most Significant Byte (MSB) is shown on the left and
the Least Significant Byte (LSB) on the right.

For example: 0xF5

2.2.3 Decimal number representation

Decimal numbers are represented as is, without any trailing character.
For example: 245

10/68 Doc ID 022017 Rev 1

AN3955 Overview

AI18873a

ISO15693 RF

MCU

CR95HF

Contactless tag

CR95HF

library

14443 type A

Or

14443 type B

13,56 MHz RF commands

3 Overview

3.1 CR95HF overview

The CR95HF is a Radio Frenquency (RF) transceiver Integrated Circuit (IC) for 13.56 MHz
contactless tags, which includes ISO/IEC 14443, ISO/IEC 15693 and ISO/IEC 18092
protocols. It manages the RF communication with Radio Frequency Identification (RFID) or
Near Field Communication (NFC) tags. It includes trame coding, RF modulation and
contactless tag response decoding.

The CR95HF is a slave device and must be controlled by a host (Microcontroller Unit). This
library is an interface between user application function and standard peripheral driver.

The library was written in compliance with ANSI C standards.

Figure 1 describes a typical application block diagram.

Figure 1. Typical application block diagram

For more details concerning the CR95HF, please refer to CR95HF datasheet.

3.2 ISO/IEC 14443-3 overview

The ISO/IEC 14443-3 is a standard, which specifies two different RF protocols (Type A and
Type B). It describes low-level functions allowing to handle one ore more contactless tags.
As an example, the ISO/IEC 14443-3 commands can be used to read the Unique Identifier
(UID) or to perform anti-collision.

The higher level commands to read or write the user memory of contactless tags are not
described in ISO/IEC 14443-3 specifications. These commands are defined in the
contactless datasheet. For instance, the SRIX4K datasheet defines Read, Write and other
specific commands.

For more information about Read, Write or other commands, refer to the SRIX4K datasheet.
Since the frames coding specified by ISO/IEC 14443 Type A differ from Type B, the CR95HF

cannot communicate with an ISO/IEC 14443 Type A and an ISO/IEC 14443 Type B
contactless tag at the same time.

Doc ID 022017 Rev 1 11/68

Overview AN3955

MS19951V1

User functions

(user application specific)

Standard peripheral driver

(MCU specific layer)

CR95HF library

CR95HF library layer

(integrates the commands defined in CR95HF datasheet)

Protocol layer (embeds commands defined in the ISO/IEC 14443-3 specification)

ISO14443_3 type A library layer ISO14443_3 type B library layer

Product layer (embeds commands defined in the product datasheet)

SRiX4K layer

3.3 SRIX4K product overview

The SRIX4K is an STMicroelectronics contactless tag powered by an RF field. It contains
a 4-kbit EEPROM memory that can be accessed by using RF commands.

For more information about low-level commands to handle a tag and an upper level to read,
write or lock memory, refer to the SRIX4K datasheeet.

SRIX4K is compliant with ISO/IEC 14443-3 Type B frame format specification.

3.4 Library overview

The library described in this application note is composed of three layers:

● A low-level layer supporting the commands described in the CR95HF datasheet. This

level is fully supported by the CR95HF library.

● An intermediate layer based on the ISO/IEC 14443-3 protocol. This layer is divided in

two files, one for Type A and another for Type B.

● An upper layer supporting the commands described in the SRIX4K datasheet.

The library can be downloaded from STMicroelectronics internet site at http://www.st.com.

Figure 2 shows an example of application architecture and describes the interaction

between a typical user application and the CR95HF library layers.

Figure 2. Interaction between typical user application and CR95HF library layers

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AN3955 CR95HF low level layer

4 CR95HF low level layer

For a brief description of CR95HF, refer to Section 3.1: CR95HF overview.
This layer is composed of:

● the lib_CR95HF.c source file

● the lib_CR95HF.h include file

4.1 Types

The CR95HF library functions use the following ANSI C compliant types:

typedef unsigned char uint8_t;

typedef signed char int8_t;

typedef const uint8_t uc8;

typedef signed short int int16_t;

4.2 Definition

The layer supports all the commands defined in the CR95HF datasheet. Each CR95HF
command corresponds to a specific function. As an example, the function calling the ECHO
command is int8_t CR95HF_Echo (uint8_t *pResponse).

Additional functions are described in Table 3: CR95HF layer additional functions.
Application developers can use the functions described in Table 2: CR95HF layer functions

based on CR95HF commands to create their own higher level functions.

For more details about commands, refer to the CR95HF datasheet.

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CR95HF low level layer AN3955

4.3 CR95HF layer functions

The tables below introduce the functions available in the CR95HF layer.

.

Table 2. CR95HF layer functions based on CR95HF commands

Function name Brief description

Sends an IDN command to CR95HF device. It returns its version

CR95HF_IDN

CR95HF_Echo

CR95HF_ProtocolSelect

CR95HF_SendRecv

CR95HF_Idle

CR95HF_RdReg

CR95HF_BaudRate

number. For more details about CR95HF_IDN function, refer to

Section 4.4: IDN function.

Sends an Echo command to CR95HF device which returns an Echo
response. The Echo function checks if communications can be
started between the MCU and the CR95HF. For more details about
CR95HF_Echo function, refer to Section 4.5: ECHO function.

Sends a ProtocolSelect command to CR95HF device. It selects the
RF communication protocol, configures RF parameters and switches
the RF field on. For more details about CR95HF_ProtocolSelect
function, refer to Section 4.6: ProtocolSelect function.

Sends a SendRecv command. The parameter sent to the command
is the frame which is coded according to the protocol previously
selected by issuing a ProtocolSelect command. For more details
about CR95HF_SendRecv function, refer to Section 4.7: SendRecv

function.

Sends an Idle command to the CR95HF device to switch it into low
consumption mode. For more details about CR95HF_Idle function,
refer to Section 4.8: Idle function.

Sends a ReadRegister command to the CR95HF device to read the
CR95HF internal register. For more details about CR95HF_RdReg
function, refer to Section 4.9: RdReg function.

Sends a Baudrate command to the CR95HF device. It changes the
CR95HF UART baudrate. For more details about
CR95HF_BaudRatefunction, refer to Section 4.10: BaudRate

function.

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AN3955 CR95HF low level layer

.

Table 3. CR95HF layer additional functions

Function name Brief description

Sends an RF pulse (EOF). For more details about

CR95HF_SendEOF

CR95HF_FieldOff

CR95HF_HexCommandToStringCommand

CR95HF_GetReaderErrorCode

CR95HF_IsReaderResultCodeOk

CR95HF_IsReaderErrorCode

CR95HF_IsCommandExists

CR95HF_SendEOF function, refer to Section 4.11:

SendEOF function.

Switches off the RF field. For more details about
CR95HF_FieldOff function, refer to Section 4.12:

FieldOff function.

Translates hexadecimal command code to command
name. It returns the ASCII code of the command. For
more details about
CR95HF_HexCommandToStringCommand function,
refer to Section 4.13: HexCommandToStringCommand

function.

Translates hexadecimal error code to error code
description. It returns a description of the error
contained in the ReaderReply parameter. For more
details about CR95HF_GetReaderErrorCode, refer
to Section 4.17: GetReaderErrorCode function.

Checks if returned code is a successful code. It returns
CR95HF_SUCCESS_CODE if the CR95HF command is
successful. For more details about
CR95HF_IsReaderResultCodeOk function, refer to

Section 4.14: IsReaderResultCodeOk function.

Checks if returned code is an error code. It returns
CR95HF_SUCCESS_CODE value if the CR95HF
command has returned an error code. For more details
about CR95HF_IsReaderErrorCode function, refer
to Section 4.15: IsReaderErrorCode function.

Checks if command is available. It returns
CR95HF_SUCCESS_CODE if the CmdCode value
exists. For more details about
CR95HF_IsCommandExists function, refer to

Section 4.16: IsCommandExists function.

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CR95HF low level layer AN3955

4.4 IDN function

The CR95HF_IDN function sends an IDN command to the CR95HF device.

Table 4. CR95HF_IDN function description

Prototype

Input parameter None
Output parameter pResponse: Pointer to CR95HF response
Return parameter CR95HF_SUCCESS_CODE: Function is successful.

result = int8_t CR95HF_IDN (uint8_t *pResponse)

4.5 ECHO function

The CR95HF_Echo function sends an ECHO command to the CR95HF device.

Table 5. CR95HF_Echo function description

Prototype

Input parameter None
Output parameter pResponse: Pointer to CR95HF response

result = int8_t CR95HF_Echo (uint8_t *pResponse)

Return parameter CR95HF_SUCCESS_CODE: Function is successful.

4.6 ProtocolSelect function

The CR95HF_ProtocolSelect function sends a ProtocolSelect command to the CR95HF
device.

To set up communications with a contactless tag, the ProtocolSelect command must be sent
to the CR95HF before the SendRecv commands.

Table 6. CR95HF_ProtocolSelect function description

Prototype

Input parameter

Output parameter pResponse: Pointer to CR95HF response

Return parameter

1. ISO/IEC 15693, ISO/IEC 18092, ISO/IEC 14443-3 Type A or Type B RF protocols.

result = int8_t CR95HF_ProtocolSelect(uc8
Length,uc8 Protocol,uc8 *Data,uint8_t *pResponse)

Length: Number of data bytes
Protocol: Type of protocol
Data input: Pointer to data

CR95HF_ERRORCODE_PARAMETER: Function failed
CR95HF_SUCCESS_CODE: Function is successful.
CR95HF_ERRORCODE_PARAMETERLENGTH: Parameter length is

incorrect.

(1)

The Data input parameter depends on the selected protocol. This application note applies to
ISO/IEC 14443-3 Type A and ISO/IEC 14443-3 Type B products.

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AN3955 CR95HF low level layer

Ta bl e 7 describes the ProtocolSelect command in ISO/IEC 14443-3 Type A case.

Table 7. CR95HF_ProtocolSelect ISO/IEC 14443-3 Type A protocol parameter

Parameter name Byte Bit Value Example

Command Code

Length

Protocol

Parameter

1. Optional. If not specify default FWT~86 µs

2. PP <= 0x0E and 0x01 <= MM <= 0xFE

0 7:0 0x02 0x02020200

1 7:0 0x02

2 7:0

3 7:6

5:4

3:0

5:4 7:0

0x02

protocol

Transmission data rate

Reception data rate

RFU

FWT= (256*16/fc)*(2*PP)*(MM+1)
where “PP” represents byte 4 and “MM”
byte 5.

: ISO/IEC 14443-3 Type A

ISO/IEC 14443-3 Type
A with reception and
transmission data
rates at 106 kbps

(1) (2)

Ta bl e 8 describes the ProtocolSelect command in ISO/IEC 14443-3 Type B case.

Table 8. CR95HF_ProtocolSelect ISO14443-3 Type B protocol parameter

Parameter name Byte Bit Value Example

Command Code

Length

Protocol

0 7:0 0x02 0x02020301

1 7:0 0x02

2 7:0

3 7:6

0x03

Transmission data rate

: ISO/IEC 14443-3 Type B protocol

ISO/IEC 14443-3 Type
B with reception and
transmission data
rates at 106 kbps

Reception data rate

5:4

RFU

3:0

Append CRC

Parameter

5:4 7:0

1. Optional. If not specify default FWT~300µs.

2. PP <= 0x0E and 0x01 <= MM <= 0xFE

0

1: CR95HF appends CRC
0: CR95HF does not append CRC

FWT= (256*16/fc)*(2*PP)*(MM+1)
where “PP” represents byte 4 and “MM”
byte 5.

Doc ID 022017 Rev 1 17/68

(1) (2)

The CR95HF
manages the CRC.

CR95HF low level layer AN3955

4.7 SendRecv function

The CR95HF_SendRecv function sends a SendRecv command. The CR95HF encodes the
frame, transmits it at 13.56 MHz, and decodes the contactless tag response.

The contactless tag response is then sent back in the pResponse parameter.

Table 9. CR95HF_SendRecv function description

Prototype

result = int8_t CR95HF_SendRecv (uc8
Length,uc8 *Parameters,uint8_t *pResponse)

Input parameter

Output parameter pResponse : Pointer to CR95HF response

Return parameter

Length: Number of bytes in Parameters input
Parameters input: Pointer to data

CR95HF_ERRORCODE_PARAMETER: Function failed
CR95HF_SUCCESS_CODE: Function is successful.
CR95HF_ERRORCODE_PARAMETERLENGTH: Parameter

length is incorrect.

The Parameters input depends on the selected protocol. This application note applies to
ISO/IEC 14443-3 Type A and ISO/IEC 14443-3 Type B products.

Ta bl e 1 0 describes the SendRecv command in ISO/IEC 14443-3 Type A case.

Table 10. SendRecv command in ISO/IEC 14443-3 Type A case

Parameter name Byte Bit Value Comments Example

Command Code

Length

Data

0 7:0 0x04

1 7:0 0xXX

2:X 7:0 0xXX

X+1 7

-RFU

6 0b0

Number of Data
bytes and
transmission flag

Data

Split frame

-

REQA command:

0x04022607
26:

Data (REQA

command code)

07:

number
of significant bits
(REQA is coded on 7
bits)

with

1: CR95HF

5

appends CRC

Transmission flag

0: CR95HF
does not
append CRC

4 0b0

3:0

18/68 Doc ID 022017 Rev 1

0xX

Append CRC

RFU

Number of
significant bits

AN3955 CR95HF low level layer

Ta bl e 1 1 describes the SendRecv command in ISO/IEC 14443-3 Type B case.

Table 11. SendRecv command in ISO/IEC 14443-3 Type B case

Parameter name Byte Bit Value Comments Example

Command Code

Length

Data

0 7:0 0x04

1 7:0 0xXX

2:X 7:0 0xXX

Length of entire
data

Data

-

REQB command:

0x040305000

For more information, refer to CR95HF datasheet.Ta ble 12 describes the CR95HF success
response value for ISO/IEC 14443-3 Type A.

Table 12. CR95HF success response value for ISO/IEC 14443-3 Type A

Parameter

name

Result
Code

Length

Data

Byte Bit Value Comments Example

0 7:0 0x04

1 7:0 0xXX

2:X 7:0 0xXX

X+1 7

1: CR95HF has
detected a collision

0: No collision detected

60

Success code

Number of bytes of Data
+ control bytes

Contactless tag response

Collision between two
contactless tag
responses

RFU

0X80054400280000

where:

80: success
05: Number of bytes
4400: ATQA
28: CRC error

Number of significant
bits: 8

00 00: No collision

detected

(1)

&

1: CRC error

5

0: No CRC error

1: Parity error

4

Control
bytes

0: No Parity error

3:0

X+2 7:0 0xXX

X+3 7:4 0b000

3:0 0bXXXX

1. CRC error bit is set but there is no CRC on ATQA response. So this bit is not significant.

2. Since the ISO/IEC 14443-3 Type A is a bit-oriented protocol, CR95HF can receive a non integer amount of
bytes.

3. To calculate the point of collision between two contactless tag responses, the user application must refer to
the control bytes. The byte where the collision is detected is indicated by Control Byte X+2 (Index of first
byte), and the specific bit in the byte where the collision is detected is indicated by Control Byte X+3 (Index
of first bit). Both indices start from 0 and the bit index can be 8, meaning that the collision affected parity.
This information is only valid if the Collision Dectected bit (Bit 7 of control Byte X+1) is set.

CRC error on contactless
response

Parity error on
contactless response

Number of significant bits
in the first byte

Index of the first byte
where the collision is
detected

RFU

Index of the first bit where
the collision is detected

(2)

(3)

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CR95HF low level layer AN3955

CR95HF returns a specific correct code for ACK or NAK contactless response, coded on 4
bits, as described in Tabl e 1 3.

Table 13. Specific success code for ACK or NAK contactless response

Parameter name Byte Bit Value Comments

Result Code

Length

0 7:0 0x90

1 7:0 0x04

Success code

Number of valid bits: 4

2:X 7:0 0x01: NAK

Data

0x05: NAK

Contactless tag response

0x0A: ACK

Ta bl e 1 4 describes the CR95HF success response value for ISO/IEC 14443-3 Type B.

Table 14. CR95HF success response value for ISO/IEC 14443-3 Type B

Parameter

name

Result Code

Length

Data

Byte Bit Value Comments Example

0 7:0 0x80

1 7:0 0xXX

2:X 7:0 0xXX

X+1 7:2 0b0000

Success code

Number of bytes of
Data + control bytes

Contactless tag
response

RFU

0x800F50AA0B000500
000000B371716A2100

where:

80: Success
0F: Number of byte
50AA0B000500000000
B371716A21:

ATQB

00: CRC Ok

Control
bytes

1 1: CRC error

0: no CRC error

CRC error or
contactless
response

0

-RFU

For more information, refer to CR95HF datasheet.

If CR95HF_SendRecv function fails, the CR95HF returns an error code in the pResponse
parameter (see Ta bl e 1 5 ). As an example, if no contactless tag is present in the RF field, the
CR95HF response is 0x8700.

Table 15. CR95HF error response value for ISO/IEC 14443-3 Type A and B

Parameter name Byte Bit Value Example

Result code

Length

0 7:0 0x08

1 7:0 0x00

For more information about CR95HF error code, refer to CR95HF datasheet.

20/68 Doc ID 022017 Rev 1

0x8700

tag in the field

: no contactless

AN3955 CR95HF low level layer

4.8 Idle function

This function sends an Idle command to the CR95HF to switch the CR95HF device into low
consumption mode. Ta b le 1 6 describes the CR95HF_Idle function.

Table 16.

Prototype

Input parameter

Output parameter pResponse : Pointer to the CR95HF response

Return parameter

CR95HF_Idle function description

result = int8_t CR95HF_Idle(uc8
Length,uc8 *Data,uint8_t *pResponse);

Length: Number of data bytes
Data: Pointer to data

CR95HF_ERRORCODE_PARAMETER: Function failed
CR95HF_SUCCESS_CODE: Function is successful.
CR95HF_ERRORCODE_PARAMETERLENGTH:

Parameter length is incorrect.

4.9 RdReg function

This function sends an RdReg command to the CR95HF in order to read the CR95HF
internal register. Ta ble 17 describes the CR95HF_RdReg function.

Table 17. CR95HF_RdReg function description

result = int8_t CR95HF_RdReg(uc8

Prototype

Input parameter

Output parameter pResponse : Pointer to CR95HF response
Return parameter CR95HF_SUCCESS_CODE: Function is successful.

Length,uc8 Address,uc8 RegCount,uc8
Flags,uint8_t *pResponse);

Length : Number of bytes (Address+RegCount+Flags)
Address: Register address
RegCount: Number of bytes to read
Flags: ST reserved (must be 0x00)

4.10 BaudRate function

This function sends a BaudRate command to the CR95HF. It allows configuring the UART
baudrate. Ta bl e 1 8 describes the CR95HF_BaudRate function.

Table 18. CR95HF_BaudRate function description

Prototype

Input parameter BaudRate: New baud rate = 13.56/(2*BaudRate+2) Mbps
Output parameter pResponse : Pointer to the CR95HF response
Return parameter CR95HF_SUCCESS_CODE: Function is successful.

For more information about this command, please refer to CR95HF datasheet.

result = int8_t CR95HF_BaudRate (uc8
BaudRate,uint8_t *pResponse);

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