SRI512-W41GE

SRI512 13.56 MHz short-range contactless memory chip with 512-bit EEPROM and anticollision functions Features ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ISO 14443-2 Type B air interface compliant ISO 14443-3 Type B frame format compliant 13.56 MHz carrier frequency 847 kHz subcarrier frequency 106 Kbit/second data transfer 8 bit Chip_ID based anticollision system 2 Count-down binary counters with automated antitearing protection 64-bit Unique Identifier 512-bit EEPROM with write protect feature Read_block and Write_block (32 bits) Internal tuning capacitor 1million erase/write cycles 40-year data retention Self-timed programming cycle 5 ms typical programming time – Unsawn wafer – Bumped and sawn wafer August 2008 Rev 4 1/47 www.st.com 1 Contents SRI512 Contents 1 2 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Signal description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.1 AC1, AC0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 3 Data transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 3.1 Input data transfer from the reader to the SRI512 (request frame) . . . . . . 9 3.1.1 3.1.2 3.1.3 Character transmission format for request frame . . . . . . . . . . . . . . . . . . 9 Request start of frame . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Request end of frame . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 3.2 Output data transfer from the SRI512 to the reader (answer frame) . . . . 11 3.2.1 3.2.2 3.2.3 Character transmission format for answer frame . . . . . . . . . . . . . . . . . . 11 Answer start of frame . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Answer end of frame . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 3.3 3.4 Transmission frame . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 CRC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 4 Memory mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 4.1 4.2 4.3 4.4 Resettable OTP area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 32-bit binary counters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 EEPROM area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 System area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 4.4.1 4.4.2 OTP_Lock_Reg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Fixed Chip_ID (option) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 5 6 SRI512 operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 SRI512 states . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 6.1 6.2 6.3 6.4 6.5 Power-off state . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Ready state . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Inventory state . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Selected state . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Deselected state . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 2/47 SRI512 Contents 6.6 Deactivated state . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 7 Anticollision . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 7.1 Description of an anticollision sequence . . . . . . . . . . . . . . . . . . . . . . . . . 26 8 SRI512 commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 8.1 8.2 8.3 8.4 8.5 8.6 8.7 8.8 8.9 8.10 Initiate() command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Pcall16() command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Slot_marker(SN) command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Select(Chip_ID) command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Completion() command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Reset_to_inventory() command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Read_block(Addr) command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 Write_block (Addr, Data) command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 Get_UID() command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 Power-on state . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 9 10 11 Maximum rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 DC and AC parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Part numbering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Appendix A ISO 14443 Type B CRC calculation . . . . . . . . . . . . . . . . . . . . . . . . . 43 Appendix B SRI512 command brief . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 3/47 List of tables SRI512 List of tables Table 1. Table 2. Table 3. Table 4. Table 5. Table 6. Table 7. Table 8. Table 9. Table 10. Table 11. Signal names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Bit description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 SRI512 memory mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Standard anticollision sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Command code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Operating conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 DC characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 AC characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Ordering information scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 4/47 SRI512 List of figures List of figures Figure 1. Figure 2. Figure 3. Figure 4. Figure 5. Figure 6. Figure 7. Figure 8. Figure 9. Figure 10. Figure 11. Figure 12. Figure 13. Figure 14. Figure 15. Figure 16. Figure 17. Figure 18. Figure 19. Figure 20. Figure 21. Figure 22. Figure 23. Figure 24. Figure 25. Figure 26. Figure 27. Figure 28. Figure 29. Figure 30. Figure 31. Figure 32. Figure 33. Figure 34. Figure 35. Figure 36. Figure 37. Figure 38. Figure 39. Figure 40. Figure 41. Figure 42. Figure 43. Figure 44. Figure 45. Figure 46. Figure 47. Figure 48. Logic diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Die floor plan. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 10% ASK modulation of the received wave . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 SRI512 request frame character format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Request start of frame . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Request end of frame . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Wave transmitted using BPSK subcarrier modulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Answer start of frame . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Answer end of frame. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Example of a complete transmission frame . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 CRC transmission rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Resettable OTP area (addresses 0 to 4) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Write_block update in standard mode (binary format) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Write_block update in reload mode (binary format) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Binary counter (addresses 5 to 6). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Count down example (binary format) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 EEPROM (addresses 7 to 15) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 System area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 State transition diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 SRI512 Chip_ID description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Description of a possible anticollision sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Example of an anticollision sequence. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Initiate request format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Initiate response format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Initiate frame exchange between reader and SRI512 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Pcall16 request format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Pcall16 response format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Pcall16 frame exchange between reader and SRI512 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Slot_marker request format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Slot_marker response format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Slot_marker frame exchange between reader and SRI512 . . . . . . . . . . . . . . . . . . . . . . . . 31 Select request format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Select response format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Select frame exchange between reader and SRI512 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Completion request format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Completion response format. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Completion frame exchange between reader and SRI512 . . . . . . . . . . . . . . . . . . . . . . . . . 33 Reset_to_inventory request format. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Reset_to_inventory response format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Reset_to_inventory frame exchange between reader and SRI512 . . . . . . . . . . . . . . . . . . 34 Read_block request format. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 Read_block response format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 Read_block frame exchange between reader and SRI512 . . . . . . . . . . . . . . . . . . . . . . . . 35 Write_block request format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 Write_block response format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 Write_block frame exchange between reader and SRI512 . . . . . . . . . . . . . . . . . . . . . . . . 37 Get_UID request format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 Get_UID response format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 5/47 List of figures Figure 49. Figure 50. Figure 51. Figure 52. Figure 53. Figure 54. Figure 55. Figure 56. Figure 57. Figure 58. Figure 59. Figure 60. SRI512 64-bit unique identifier of the SRI512 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 Get_UID frame exchange between reader and SRI512 . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 SRI512 synchronous timing, transmit and receive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 Initiate frame exchange between reader and SRI512 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 Pcall16 frame exchange between reader and SRI512 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 Slot_marker frame exchange between reader and SRI512 . . . . . . . . . . . . . . . . . . . . . . . . 44 Select frame exchange between reader and SRI512 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 Completion frame exchange between reader and SRI512 . . . . . . . . . . . . . . . . . . . . . . . . . 44 Reset_to_inventory frame exchange between reader and SRI512 . . . . . . . . . . . . . . . . . . 45 Read_block frame exchange between reader and SRI512 . . . . . . . . . . . . . . . . . . . . . . . . 45 Write_block frame exchange between reader and SRI512 . . . . . . . . . . . . . . . . . . . . . . . . 45 Get_UID frame exchange between reader and SRI512 . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 6/47 SRI512 Description 1 Description The SRI512 is a contactless memory, powered by an externally transmitted radio wave. It contains a 512-bit user EEPROM fabricated with STMicroelectronics CMOS technology. The memory is organized as 16 blocks of 32 bits. The SRI512 is accessed via the 13.56 MHz carrier. Incoming data are demodulated and decoded from the received amplitude shift keying (ASK) modulation signal and outgoing data are generated by load variation using bit phase shift keying (BPSK) coding of a 847 kHz subcarrier. The received ASK wave is 10% modulated. The data transfer rate between the SRI512 and the reader is 106 Kbit/s in both reception and emission modes. The SRI512 follows the ISO 14443-2 Type B recommendation for the radio-frequency power and signal interface. Figure 1. Logic diagram SRI512 Power Supply Regulator 512-bit User EEPROM ASK Demodulator BPSK Load Modulator AC1 AC0 AI10795 The SRI512 is specifically designed for short range applications that need re-usable products. The SRI512 includes an anticollision mechanism that allows it to detect and select tags present at the same time within range of the reader. Using the STMicroelectronics single chip coupler, CRX14, it is easy to design a reader and build a contactless system. Table 1. Signal names Signal name AC1 AC0 Antenna coil Antenna coil Description 7/47 Signal description SRI512 The SRI512 contactless EEPROM can be randomly read and written in block mode (each block containing 32 bits). The instruction set includes the following nine commands: ● ● ● ● ● ● ● ● ● Read_block Write_block Initiate Pcall16 Slot_marker Select Completion Reset_to_inventory Get_UID The SRI512 memory is organized in three areas, as described in Table 3. The first area is a resettable OTP (one-time programmable) area in which bits can only be switched from 1 to 0. Using a special command, it is possible to erase all bits of this area to 1. The second area provides two 32-bit binary counters that can only be decremented from FFFF FFFFh to 0000 0000h, and gives a capacity of 4,294,967,296 units per counter. The last area is the EEPROM memory. It is accessible by block of 32 bits and includes an auto-erase cycle during each Write_block command. Figure 2. Die floor plan AC0 AC1 AI09055 2 2.1 Signal description AC1, AC0 The pads for the Antenna Coil. AC1 and AC0 must be directly bonded to the antenna. 8/47 SRI512 Data transfer 3 3.1 Data transfer Input data transfer from the reader to the SRI512 (request frame) The reader must generate a 13.56 MHz sinusoidal carrier frequency at its antenna, with enough energy to “remote-power” the memory. The energy received at the SRI512’s antenna is transformed into a supply voltage by a regulator, and into data bits by the ASK demodulator. For the SRI512 to decode correctly the information it receives, the reader must 10% amplitude-modulate the 13.56 MHz wave before sending it to the SRI512. This is represented in Figure 3. The data transfer rate is 106 Kbits/s. Figure 3. 10% ASK modulation of the received wave DAT BIT TO TRANSMIT A TO THE SRI512 10% ASK MODULATION OF THE 13.56MHz WAVE, GENERATED BY THE READER Transfer time for one data bit is 1/106 kHz Ai10796 3.1.1 Character transmission format for request frame The SRI512 transmits and receives data bytes as 10-bit characters, with the least significant bit (b0) transmitted first, as shown in Figure 4. Each bit duration, an ETU (elementary time unit), is equal to 9.44 µs (1/106 kHz). These characters, framed by a start of frame (SOF) and an end of frame (EOF), are put together to form a command frame as shown in Figure 10. A frame includes an SOF, commands, addresses, data, a CRC and an EOF as defined in the ISO 14443-3 Type B Standard. If an error is detected during data transfer, the SRI512 does not execute the command, but it does not generate an error frame. Figure 4. SRI512 request frame character format b0 1 ETU Start "0" b1 LSb b2 b3 b4 b5 b6 b7 b8 MSb b9 Stop "1" Information Byte ai07664 9/47 Data transfer Table 2. Bit b0 b1 to b8 b9 SRI512 Bit description Description Start bit used to synchronize the transmission Information byte (command, address or data) Stop bit used to indicate the end of a character Value b0 = 0 The information byte is sent with the least significant bit first b9 = 1 3.1.2 Request start of frame The SOF described in Figure 5 is composed of: ● ● ● ● one falling edge, followed by 10 ETUs at logic-0, followed by a single rising edge, followed by at least 2 ETUs (and at most 3) at logic-1. Request start of frame b0 ETU 0 b1 0 b2 0 b3 0 b4 0 b5 0 b6 0 b7 0 b8 0 b9 0 b10 1 b11 1 Figure 5. ai07665 3.1.3 Request end of frame The EOF shown in Figure 6 is composed of: ● ● ● one falling edge, followed by 10 ETUs at logic-0, followed by a single rising edge. Request end of frame b0 ETU 0 b1 0 b2 0 b3 0 b4 0 b5 0 b6 0 b7 0 b8 0 b9 0 Figure 6. ai07666 10/47 SRI512 Data transfer 3.2 Output data transfer from the SRI512 to the reader (answer frame) The data bits issued by the SRI512 use back-scattering. Back-scattering is obtained by modifying the SRI512 current consumption at the antenna (load modulation). The load modulation causes a variation at the reader antenna by inductive coupling. With appropriate detector circuitry, the reader is able to pick up information from the SRI512. To improve loadmodulation detection, data is transmitted using a BPSK encoded, 847 kHz subcarrier frequency ƒs as shown in Figure 7, and as specified in the ISO 14443-2 Type B Standard. Figure 7. Wave transmitted using BPSK subcarrier modulation Data Bit to be Transmitted to the Reader Or 847kHz BPSK Modulation Generated by the SRI512 BPSK Modulation at 847kHz During a One-bit Data Transfer Time (1/106kHz) AI10797 3.2.1 Character transmission format for answer frame The character format is the same as for input data transfer (Figure 4). The transmitted frames are made up of an SOF, data, a CRC and an EOF (Figure 10). As with an input data transfer, if an error occurs, the reader does not issue an error code to the SRI512, but it should be able to detect it and manage the situation. The data transfer rate is 106 Kbits/second. 3.2.2 Answer start of frame The SOF described in Figure 8 is composed of: ● ● followed by 10 ETUs at logic-0 followed by 2 ETUs at logic-1 Answer start of frame b0 ETU 0 b1 0 b2 0 b3 0 b4 0 b5 0 b6 0 b7 0 b8 0 b9 0 b10 1 b11 1 Figure 8. ai07665 11/47 Data transfer SRI512 3.2.3 Answer end of frame The EOF shown in Figure 9 is composed of: ● ● followed by 10 ETUs at logic-0, followed by 2 ETUs at logic-1. Answer end of frame b0 ETU 0 b1 0 b2 0 b3 0 b4 0 b5 0 b6 0 b7 0 b8 0 b9 0 b10 1 b11 1 Figure 9. ai07665 3.3 Transmission frame Between the request data transfer and the answer data transfer, all ASK and BPSK modulations are suspended for a minimum time of t0 = 128/ƒS. This delay allows the reader to switch from Transmission to Reception mode. It is repeated after each frame. After t0, the 13.56 MHz carrier frequency is modulated by the SRI512 at 847 kHz for a period of t1 = 128/ƒS to allow the reader to synchronize. After t1, the first phase transition generated by the SRI512 forms the start bit (‘0’) of the answer SOF. After the falling edge of the answer EOF, the reader waits a minimum time, t2, before sending a new request frame to the SRI512. Figure 10. Example of a complete transmission frame Sent by the Reader SOF 12 bits Cmd 10 bits Data 10 bits CRC 10 bits CRC 10 bits EOF 10 bits SOF at 106kb/s Sent by the SRI512 t DR fs=847.5kHz Sync SOF 12 bits Data CRC CRC EOF 10 bits 10 bits 10 bits 12 bits t0 128/fs t1 128/fs t2 Input data transfer using ASK Output data transfer using BPSK Ai10798 12/47 SRI512 Data transfer 3.4 CRC The 16-bit CRC used by the SRI512 is generated in compliance with the ISO14443 Type B recommendation. For further information, please see Appendix A. The initial register contents are all 1’s: FFFFh. The two-byte CRC is present in every request and in every answer frame, before the EOF. The CRC is calculated on all the bytes between SOF (not included) and the CRC field. Upon reception of a request from a reader, the SRI512 verifies that the CRC value is valid. If it is invalid, the SRI512 discards the frame and does not answer the reader. Upon reception of an answer from the SRI512, the reader should verify the validity of the CRC. In case of error, the actions to be taken are the reader designer’s responsibility. The CRC is transmitted with the least significant byte first and each byte is transmitted with the least significant bit first. Figure 11. CRC transmission rules LSByte LSbit MSbit LSbit MSByte MSbit CRC 16 (8 bits) CRC 16 (8 bits) ai07667 13/47 Memory mapping SRI512 4 Memory mapping The SRI512 is organized as 16 blocks of 32 bits as shown in Table 3. All blocks are accessible by the Read_block command. Depending on the write access, they can be updated by the Write_block command. A Write_block updates all the 32 bits of the block. Table 3. SRI512 memory mapping Block Msb Addr b31 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 32-bit block b16 b15 b14 b8 b7 Lsb b0 Description 32 bits Boolean area 32 bits Boolean area 32 bits Boolean area 32 bits Boolean area 32 bits Boolean area 32 bits binary counter 32 bits binary counter User area User area User area User area User area User area User area User area User area Lockable EEPROM Count down Counter Resettable OTP bits 255 OTP_Lock_Reg 0 ST Reserved Fixed Chip_ID (Option) System OTP bits UID0 64 bits UID area UID1 ROM 14/47 SRI512 Memory mapping 4.1 Resettable OTP area This area contains five individual 32-bit Boolean words (see Figure 12 for a map of the area). A Write_block command will not erase the previous contents of the block as the write cycle is not preceded by an auto-erase cycle. This feature can be used to reset selected bits from 1 to 0. All bits previously at 0 remain unchanged. When the 32 bits of a block are all at 0, the block is empty, and cannot be updated any more. See Figure 13 and Figure 14 for examples of the result of the Write_block command in the resettable OTP area. Figure 12. Resettable OTP area (addresses 0 to 4) Block Address 0 1 2 3 4 MSb b31 32-bit Block b16 b15 b14 32-bit Boolean Area 32-bit Boolean Area 32-bit Boolean Area 32-bit Boolean Area 32-bit Boolean Area ai12381 b8 b7 LSb b0 Description Resettable OTP Bit Figure 13. Write_block update in standard mode (binary format) b31 Previous data stored in block 1 ... 1 1 0 1 0 1 1 1 1 1 0 1 b0 1 Data to be written 1 ... 1 0 0 1 0 1 1 0 0 1 1 1 1 New data stored in block 1 ... 1 0 0 1 0 1 1 0 0 1 0 1 1 ai07658 The five 32-bit blocks making up the Resettable OTP area can be erased in one go by adding an auto-erase cycle to the Write_block command. An auto-erase cycle is added each time the SRI512 detects a Reload command. The Reload command is implemented through a specific update of the 32-bit binary counter located at block address 6 (see Section 4.2: 32-bit binary counters for details). 15/47 Memory mapping Figure 14. Write_block update in reload mode (binary format) b31 Previous data stored in block 1 ... 1 1 0 1 0 1 1 1 1 1 0 SRI512 b0 1 1 Data to be written 1 ... 1 1 1 1 0 1 1 0 0 1 1 1 1 New data stored in block 1 ... 1 1 1 1 0 1 1 0 0 1 1 1 1 ai07659 4.2 32-bit binary counters The two 32-bit binary counters located at block addresses 5 and 6, respectively, are used to count down from 232 (4096 million) to 0. The SRI512 uses dedicated logic that only allows the update of a counter if the new value is lower than the previous one. This feature allows the application to count down by steps of 1 or more. The initial value in the counter is FFFF FFFFh. When the value displayed is 0000 0000h, the counter is empty and cannot be reloaded. The counter is updated by issuing the Write_block command to block address 5 or 6, depending on which counter is to be updated. The Write_block command writes the new 32-bit value to the counter block address. Figure 16 shows examples of how the counters operate. The counter programming cycles are protected by automated antitearing logic. This function allows the counter value to be protected in case of power down within the programming cycle. In case of power down, the counter value is not updated and the previous value continues to be stored. Blocks 5 and 6 can be write-protected using the OTP_Lock_Reg bits (block 255). Once a block has been protected, its contents cannot be modified. A protected counter block behaves like a ROM block. Figure 15. Binary counter (addresses 5 to 6) Block Address 5 6 MSb b31 32-bit Block b16 b15 b14 32-bit Binary Counter 32-bit Binary Counter b8 b7 LSb b0 Count down Counter ai12384 Description 16/47 SRI512 Figure 16. Count down example (binary format) b31 Initial data 1 ... 1 1 1 1 1 1 1 1 1 Memory mapping b0 1 1 1 1 1-unit decrement 1 ... 1 1 1 1 1 1 1 1 1 1 1 1 0 1-unit decrement 1 ... 1 1 1 1 1 1 1 1 1 1 1 0 1 1-unit decrement 1 ... 1 1 1 1 1 1 1 1 1 1 1 0 0 8-unit decrement 1 ... 1 1 1 1 1 1 1 1 1 0 1 0 0 Increment not allowed 1 ... 1 1 1 1 1 1 1 1 1 1 0 0 0 ai07661 The counter with block address 6 controls the Reload command used to reset the resettable OTP area (addresses 0 to 4). Bits b31 to b21 act as an 11-bit Reload counter; whenever one of these 11 bits is updated, the SRI512 detects the change and adds an Erase cycle to the Write_block command for locations 0 to 4 (see Section 4.1: Resettable OTP area). The Erase cycle remains active until a Power-off or a Select command is issued. The SRI512’s resettable OTP area can be reloaded up to 2,047 times (211-1). 17/47 Memory mapping SRI512 4.3 EEPROM area The 9 blocks between addresses 7 and 15 are EEPROM blocks of 32 bits each (36 bytes in total). (See Figure 17 for a map of the area.) These blocks can be accessed using the Read_block and Write_block commands. The Write_block command for the EEPROM area always includes an auto-erase cycle prior to the write cycle. Blocks 7 to 15 can be write-protected. Write access is controlled by the 9 bits of the OTP_Lock_Reg located at block address 255 (see Section 4.4.1: OTP_Lock_Reg for details). Once protected, these blocks (7 to 15) cannot be unprotected Figure 17. EEPROM (addresses 7 to 15) Block address 7 8 9 10 11 12 13 14 15 MSb b31 32-bit block b16 b15 b14 User area User area User area User area User area User area User area User area User area Lockable EEPROM b8 b7 LSb b0 Description Ai12383b 18/47 SRI512 Memory mapping 4.4 System area This area is used to modify the settings of the SRI512. It contains 3 registers: OTP_Lock_Reg, Fixed Chip_ID and ST Reserved. See Figure 18 for a map of this area. A Write_block command in this area will not erase the previous contents. Selected bits can thus be set from 1 to 0. All bits previously at 0 remain unchanged. Once all the 32 bits of a block are at 0, the block is empty and cannot be updated any more. Figure 18. System area Block Address MSb b31 OTP_Lock_Reg 32-bit Block b16 b15 b14 0 b8 b7 LSb b0 OTP ai12374b Description 255 ST Reserved Fixed Chip_ID (Option) 4.4.1 OTP_Lock_Reg The 16 bits, b31 to b16, of the System area (block address 255) are used as OTP_Lock_Reg bits in the SRI512. They control the write access to the 16 blocks 0 to 15 as follows: ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● When b16 is at 0, block 0 is write-protected When b17 is at 0, block 1 is write-protected When b18 is at 0, block 2 is write-protected When b19 is at 0, block 3 is write-protected When b20 is at 0, block 4 is write-protected When b21 is at 0, block 5 is write-protected When b22 is at 0, block 6 is write-protected When b23 is at 0, block 7 is write-protected When b24 is at 0, block 8 is write-protected When b25 is at 0, block 9 is write-protected When b26 is at 0, block 10 is write-protected When b27 is at 0, block 11 is write-protected When b28 is at 0, block 12 is write-protected When b29 is at 0, block 13 is write-protected When b30 is at 0, block 14 is write-protected When b31 is at 0, block 15 is write-protected. The OTP_Lock_Reg bits cannot be erased. Once write-protected, the blocks behave like ROM blocks and cannot be unprotected. After any modification of the OTP_Lock_Reg bits, it is necessary to send a Select command with a valid Chip_ID to the SRI512 in order to load the block write protection into the logic. 19/47 Memory mapping SRI512 4.4.2 Fixed Chip_ID (option) The SRI512 is provided with an anticollision feature based on a random 8-bit Chip_ID. Prior to selecting an SRI512, an anticollision sequence has to be run to search for the Chip_ID of the SRI512. This is a very flexible feature, however the searching loop requires time to run. For some applications, much time could be saved by knowing the value of the SRI512 Chip_ID beforehand, so that the SRI512 can be identified and selected directly without having to run an anticollision sequence. This is why the SRI512 was designed with an optional mask setting used to program a fixed 8-bit Chip_ID to bits b7 to b0 of the system area. When the fixed Chip_ID option is used, the random Chip_ID function is disabled. 20/47 SRI512 SRI512 operation 5 SRI512 operation All commands, data and CRC are transmitted to the SRI512 as 10-bit characters using ASK modulation. The start bit of the 10 bits, b0, is sent first. The command frame received by the SRI512 at the antenna is demodulated by the 10% ASK demodulator, and decoded by the internal logic. Prior to any operation, the SRI512 must have been selected by a Select command. Each frame transmitted to the SRI512 must start with a start of frame, followed by one or more data characters, two CRC bytes and the final end of frame. When an invalid frame is decoded by the SRI512 (wrong command or CRC error), the memory does not return any error code. When a valid frame is received, the SRI512 may have to return data to the reader. In this case, data is returned using BPSK encoding, in the form of 10-bit characters framed by an SOF and an EOF. The transfer is ended by the SRI512 sending the 2 CRC bytes and the EOF. 21/47 SRI512 states SRI512 6 SRI512 states The SRI512 can be switched into different states. Depending on the current state of the SRI512, its logic will only answer to specific commands. These states are mainly used during the anticollision sequence, to identify and to access the SRI512 in a very short time. The SRI512 provides 6 different states, as described in the following paragraphs and in Figure 19. 6.1 Power-off state The SRI512 is in Power-off state when the electromagnetic field around the tag is not strong enough. In this state, the SRI512 does not respond to any command. 6.2 Ready state When the electromagnetic field is strong enough, the SRI512 enters the Ready state. After Power-up, the Chip_ID is initialized with a random value. The whole logic is reset and remains in this state until an Initiate() command is issued. Any other command will be ignored by the SRI512. 6.3 Inventory state The SRI512 switches from the Ready to the Inventory state after an Initiate() command has been issued. In Inventory state, the SRI512 will respond to any anticollision commands: Initiate(), Pcall16() and Slot_marker(), and then remain in the Inventory state. It will switch to the Selected state after a Select(Chip_ID) command is issued, if the Chip_ID in the command matches its own. If not, it will remain in Inventory state. 6.4 Selected state In Selected state, the SRI512 is active and responds to all Read_block(), Write_block(), and Get_UID() commands. When an SRI512 has entered the Selected state, it no longer responds to anticollision commands. So that the reader can access another tag, the SRI512 can be switched to the Deselected state by sending a Select(Chip_ID2) with a Chip_ID that does not match its own, or it can be placed in Deactivated state by issuing a Completion() command. Only one SRI512 can be in Selected state at a time. 6.5 Deselected state Once the SRI512 is in Deselected state, only a Select(Chip_ID) command with a Chip_ID matching its own can switch it back to Selected state. All other commands are ignored. 6.6 Deactivated state When in this state, the SRI512 can only be turned off. All commands are ignored. 22/47 SRI512 Figure 19. State transition diagram SRI512 states Power-off Out of field On field Ready Chip_ID8bits = RND Initiate() Out of field Out of field Inventory Select(Chip_ID) Reset_to_inventory() Out of field Select(Chip_ID) Deselected Select( Selected Completion() Out of field Deactivated Initiate() or Pcall16() or Slot_marker(SN) or Select(wrong Chip_ID) ≠ Chip_ID) Select(Chip_ID) Read_block() Write_block() Get_UID() AI10794b 23/47 Anticollision SRI512 7 Anticollision The SRI512 provides an anticollision mechanism that searches for the Chip_ID of each device that is present in the reader field range. When known, the Chip_ID is used to select an SRI512 individually, and access its memory. The anticollision sequence is managed by the reader through a set of commands described in Section 5: SRI512 operation: ● ● ● Initiate() Pcall16() Slot_marker(). The reader is the master of the communication with one or more SRI512 device(s). It initiates the tag communication activity by issuing an Initiate(), Pcall16() or Slot_marker() command to prompt the SRI512 to answer. During the anticollision sequence, it might happen that two or more SRI512 devices respond simultaneously, so causing a collision. The command set allows the reader to handle the sequence, to separate SRI512 transmissions into different time slots. Once the anticollision sequence has completed, SRI512 communication is fully under the control of the reader, allowing only one SRI512 to transmit at a time. The Anticollision scheme is based on the definition of time slots during which the SRI512 devices are invited to answer with minimum identification data: the Chip_ID. The number of slots is fixed at 16 for the Pcall16() command. For the Initiate() command, there is no slot and the SRI512 answers after the command is issued. SRI512 devices are allowed to answer only once during the anticollision sequence. Consequently, even if there are several SRI512 devices present in the reader field, there will probably be a slot in which only one SRI512 answers, allowing the reader to capture its Chip_ID. Using the Chip_ID, the reader can then establish a communication channel with the identified SRI512. The purpose of the anticollision sequence is to allow the reader to select one SRI512 at a time. The SRI512 is given an 8-bit Chip_ID value used by the reader to select only one among up to 256 tags present within its field range. The Chip_ID is initialized with a random value during the Ready state, or after an Initiate() command in the Inventory state. The four least significant bits (b0 to b3) of the Chip_ID are also known as the Chip_slot_number. This 4-bit value is used by the Pcall16() and Slot_marker() commands during the anticollision sequence in the Inventory state. Figure 20. SRI512 Chip_ID description b7 b6 b5 b4 b3 8-bit Chip_ID b0 to b3: CHIP_SLOT_NUMBER ai07668 b2 b1 b0 Each time the SRI512 receives a Pcall16() command, the Chip_slot_number is given a new 4-bit random value. If the new value is 0000b, the SRI512 returns its whole 8-bit Chip_ID in its answer to the Pcall16() command. The Pcall16() command is also used to define the slot number 0 of the anticollision sequence. When the SRI512 receives the Slot_marker(SN) command, it compares its Chip_slot_number with the Slot_number parameter (SN). If they match, the SRI512 returns its Chip_ID as a response to the command. If they do not, the SRI512 does not answer. The Slot_marker(SN) command is used to define all the anticollision slot numbers from 1 to 15. 24/47 SRI512 Slot 0 Slot 1 Slot 2 Slot N Slot 15 < > E S Slot O Marker O F F (2) S O F ... S Answer E O Chip_ID O X1h F F S Slot O Marker F (15) > < > < < > Reader S E PCALL 16 O O Request F F S Slot E O Marker O F F (1) E O F SRI devices S Answer E O Chip_ID O X0h F F S Answer E O Chip_ID O F F X1h ... E O F S O F Answer Chip_ID XFh E O F t2 t0 + t1 t2 < t3 > t2 t0 + t1 t2 Figure 21. Description of a possible anticollision sequence Timing t0 + t1 1. The value X in the answer Chip_ID means a random hexadecimal character from 0 to F. No collision Collision No Answer No collision Comment Time > Ai10799 Anticollision 25/47 Anticollision SRI512 7.1 Description of an anticollision sequence The anticollision sequence is initiated by the Initiate() command which triggers all the SRI512 devices that are present in the reader field range, and that are in Inventory state. Only SRI512 devices in Inventory state will respond to the Pcall16() and Slot_marker(SN) anticollision commands. A new SRI512 introduced in the field range during the anticollision sequence will not be taken into account as it will not respond to the Pcall16() or Slot_marker(SN) command (Ready state). To be considered during the anticollision sequence, it must have received the Initiate() command and entered the Inventory state. Table 4 shows the elements of a standard anticollision sequence. (See Figure 22 for an example.) Table 4. Standard anticollision sequence Send Initiate(). Step 1 Init: – If no answer is detected, go to step1. – If only 1 answer is detected, select and access the SRI512. After accessing the SRI512, deselect the tag and go to step1. – If a collision (many answers) is detected, go to step2. Send Pcall16(). Step 2 Slot 0 – If no answer or collision is detected, go to step3. – If 1 answer is detected, store the Chip_ID, Send Select() and go to step3. Send Slot_marker(1). Step 3 Slot 1 – If no answer or collision is detected, go to step4. – If 1 answer is detected, store the Chip_ID, Send Select() and go to step4. Send Slot_marker(2). Step 4 Slot 2 – If no answer or collision is detected, go to step5. – If 1 answer is detected, store the Chip_ID, Send Select() and go to step5. Send Slot_marker(3 up to 14) ... Step N Slop N – If no answer or collision is detected, go to stepN+1. – If 1 answer is detected, store the Chip_ID, Send Select() and go to stepN+1. Send Slot_marker(15). Step 17 Slot 15 – If no answer or collision is detected, go to step18. – If 1 answer is detected, store the Chip_ID, Send Select() and go to step18. Step 18 All the slots have been generated and the Chip_ID values should be stored into the reader memory. Issue the Select(Chip_ID) command and access each identified SRI512 one by one. After accessing each SRI512, switch them into Deselected or Deactivated state, depending on the application needs. – If collisions were detected between Step2 and Step17, go to Step2. – If no collision was detected between Step2 and Step17, go to Step1. After each Slot_marker() command, there may be several, one or no answers from the SRI512 devices. The reader must handle all the cases and store all the Chip_IDs, correctly decoded. At the end of the anticollision sequence, after Slot_marker(15), the reader can start working with one SRI512 by issuing a Select() command containing the desired Chip_ID. If a collision is detected during the anticollision sequence, the reader has to generate a new sequence in order to identify all unidentified SRI512 devices in the field. The anticollision sequence can stop when all SRI512 devices have been identified. 26/47 SRI512 Figure 22. Example of an anticollision sequence Command READY State INITIATE () PCALL16() SELECT(30h) SLOT_MARKER(1) SLOT_MARKER(2) SELECT(12h) SLOT_MARKER(3) SLOT_MARKER(4) SLOT_MARKER(5) SLOT_MARKER(6) SLOT_MARKER(N) SLOT_MARKER(F) PCALL16() SLOT_MARKER(1) SELECT(41h) SLOT_MARKER(2) SELECT(42h) SLOT_MARKER(3) SELECT(53h) SLOT_MARKER(4) SELECT(74h) SLOT_MARKER(N) PCALL16() SELECT(50h) SLOT_MARKER(1) SLOT_MARKER(N) PCALL16() SLOT_MARKER(3) SELECT(43h) 43h 41h 41h 50h 50h 50h 53h 53h 74h 74h 40h 40h 41h 41h 42h 42h 41h 53h 42h 50h 50h 74h 45h 55h 12h 12h 43h 43h 53h 73h Tag 1 Tag 2 Tag 3 Tag 4 Tag 5 Tag 6 Tag 7 Tag 8 Comments Chip_ID Chip_ID Chip_ID Chip_ID Chip_ID Chip_ID Chip_ID Chip_ID 28h 40h 45h 75h 13h 12h 40h 3Fh 30h 30h 30h 01h 4Ah 43h 02h 50h 55h FEh 48h 43h A9h 52h 53h 7Ch 7Ch 73h Anticollision Each tag gets a random Chip_ID Each tag get a new random Chip_ID All tags answer: collisions All CHIP_SLOT_NUMBERs get a new random value Slot0: only one answer Tag3 is identified Slot1: no answer Slot2: only one answer Tag2 is identified Slot3: collisions Slot4: no answer Slot5: collisions Slot6: no answer SlotN: no answer SlotF: no answer All CHIP_SLOT_NUMBERs get a new random value Slot0: collisions Slot1: only one answer Tag4 is identified Slot2: only one answer Tag6 is identified Slot3: only one answer Tag5 is identified Slot4: only one answer Tag8 is identified SlotN: no answer All CHIP_SLOT_NUMBERs get a new random value Slot0: only one answer Tag7 is identified Slot1: only one answer but already found for tag4 SlotN: no answer All CHIP_SLOT_NUMBERs get a new random value Slot0: only one answer Slot3: only one answer Tag1 is identified All tags are identified 43h 43h ai07669 27/47 SRI512 commands SRI512 8 SRI512 commands See the paragraphs below for a detailed description of the Commands available on the SRI512. The commands and their hexadecimal codes are summarized in Table 5. A brief is given in Appendix B. Table 5. Command code Hexadecimal Code 06h-00h 06h-04h x6h 08h 09h 0Bh 0Ch 0Eh 0Fh Initiate() Pcall16() Slot_marker (SN) Read_block(Addr) Write_block(Addr, Data) Get_UID() Reset_to_inventory Select(Chip_ID) Completion() Command 28/47 SRI512 SRI512 commands 8.1 Initiate() command Command code = 06h - 00h Initiate() is used to initiate the anticollision sequence of the SRI512. On receiving the Initiate() command, all SRI512 devices in Ready state switch to Inventory state, set a new 8bit Chip_ID random value, and return their Chip_ID value. This command is useful when only one SRI512 in Ready state is present in the reader field range. It speeds up the Chip_ID search process. The Chip_slot_number is not used during Initiate() command access. Figure 23. Initiate request format SOF 06h Initiate 00h CRCL 8 bits CRCH 8 bits EOF AI07670b Request parameter: ● No parameter Figure 24. Initiate response format SOF Chip_ID 8 bits CRCL 8 bits CRCH 8 bits EOF AI07671 Response parameter: ● Chip_ID of the SRI512 Figure 25. Initiate frame exchange between reader and SRI512 Reader SRI512 SOF 06h 00h CRCL CRCH EOF SOF Chip_ID CRCL CRCH EOF AI10942 29/47 SRI512 commands SRI512 8.2 Pcall16() command Command code = 06h - 04h The SRI512 must be in Inventory state to interpret the Pcall16() command. On receiving the Pcall16() command, the SRI512 first generates a new random Chip_slot_number value (in the 4 least significant bits of the Chip_ID). Chip_slot_number can take on a value between 0 an 15 (1111b). The value is retained until a new Pcall16() or Initiate() command is issued, or until the SRI512 is powered off. The new Chip_slot_number value is then compared with the value 0000b. If they match, the SRI512 returns its Chip_ID value. If not, the SRI512 does not send any response. The Pcall16() command, used together with the Slot_marker() command, allows the reader to search for all the Chip_IDs when there are more than one SRI512 device in Inventory state present in the reader field range. Figure 26. Pcall16 request format SOF 06h Pcall16 04h CRCL 8 bits CRCH 8 bits EOF AI07673b Request parameter: ● No parameter Figure 27. Pcall16 response format SOF Chip_ID 8 bits CRCL 8 bits CRCH 8 bits EOF AI07671 Response parameter: ● Chip_ID of the SRI512 Figure 28. Pcall16 frame exchange between reader and SRI512 Reader SOF SRI512 06h 04h CRCL CRCH EOF SOF Chip_ID CRCL CRCH EOF AI10943 30/47 SRI512 SRI512 commands 8.3 Slot_marker(SN) command Command code = x6h The SRI512 must be in Inventory state to interpret the Slot_marker(SN) command. The Slot_marker byte code is divided into two parts: ● ● b3 to b0: 4-bit command code with fixed value 6. b7 to b4: 4 bits known as the Slot_number (SN). They assume a value between 1 and 15. The value 0 is reserved by the Pcall16() command. On receiving the Slot_marker() command, the SRI512 compares its Chip_slot_number value with the Slot_number value given in the command code. If they match, the SRI512 returns its Chip_ID value. If not, the SRI512 does not send any response. The Slot_marker() command, used together with the Pcall16() command, allows the reader to search for all the Chip_IDs when there are more than one SRI512 device in Inventory state present in the reader field range. Figure 29. Slot_marker request format SOF Slot_marker X6h CRCL 8 bits CRCH 8 bits EOF AI07675b Request parameter: ● x: Slot number Figure 30. Slot_marker response format SOF Chip_ID 8 bits CRCL 8 bits CRCH 8 bits EOF AI07671 Response parameters: ● Chip_ID of the SRI512 Figure 31. Slot_marker frame exchange between reader and SRI512 Reader SRI512 SOF X6h CRCL CRCH EOF SOF Chip_ID CRCL CRCH EOF AI10944 31/47 SRI512 commands SRI512 8.4 Select(Chip_ID) command Command code = 0Eh The Select() command allows the SRI512 to enter the Selected state. Until this command is issued, the SRI512 will not accept any other command, except for Initiate(), Pcall16() and Slot_marker(). The Select() command returns the 8 bits of the Chip_ID value. An SRI512 in Selected state, that receives a Select() command with a Chip_ID that does not match its own is automatically switched to Deselected state. Figure 32. Select request format SOF Select 0Eh Chip_ID 8 bits CRCL 8 bits CRCH 8 bits EOF AI07677b Request parameter: ● 8-bit Chip_ID stored during the anticollision sequence Figure 33. Select response format SOF Chip_ID 8 bits CRCL 8 bits CRCH 8 bits EOF AI07671 Response parameters: ● Chip_ID of the selected tag. Must be equal to the transmitted Chip_ID Figure 34. Select frame exchange between reader and SRI512 Reader SRI512 SOF 0Eh Chip_ID CRCL CRCH EOF SOF Chip_ID CRCL CRCH EOF AI10945 32/47 SRI512 SRI512 commands 8.5 Completion() command Command code = 0Fh On receiving the Completion() command, an SRI512 in Selected state switches to Deactivated state and stops decoding any new commands. The SRI512 is then locked in this state until a complete reset (tag out of the field range). A new SRI512 can thus be accessed through a Select() command without having to remove the previous one from the field. The Completion() command does not generate a response. All SRI512 devices not in Selected state ignore the Completion() command. Figure 35. Completion request format SOF Completion 0Fh CRCL 8 bits CRCH 8 bits EOF AI07679b Request parameters: ● No parameter Figure 36. Completion response format No Response AI07680 Figure 37. Completion frame exchange between reader and SRI512 Reader SRI512 SOF 0Fh CRCL CRCH EOF No Response AI10646 33/47 SRI512 commands SRI512 8.6 Reset_to_inventory() command Command code = 0Ch On receiving the Reset_to_inventory() command, all SRI512 devices in Selected state revert to Inventory state. The concerned SRI512 devices are thus resubmitted to the anticollision sequence. This command is useful when two SRI512 devices with the same 8bit Chip_ID happen to be in Selected state at the same time. Forcing them to go through the anticollision sequence again allows the reader to generates new Pcall16() commands and so, to set new random Chip_IDs. The Reset_to_inventory() command does not generate a response. All SRI512 devices that are not in Selected state ignore the Reset_to_inventory() command. Figure 38. Reset_to_inventory request format SOF Reset_to_inventory 0Ch CRCL 8 bits CRCH 8 bits EOF AI07682b Request parameter: ● No parameter Figure 39. Reset_to_inventory response format No Response AI07680 Figure 40. Reset_to_inventory frame exchange between reader and SRI512 Reader SRI512 SOF 0Ch CRCL CRCH EOF No Response AI10947 34/47 SRI512 SRI512 commands 8.7 Read_block(Addr) command Command code = 08h On receiving the Read_block command, the SRI512 reads the desired block and returns the 4 data bytes contained in the block. Data bytes are transmitted with the Least Significant byte first and each byte is transmitted with the least significant bit first. The address byte gives access to the 16 blocks of the SRI512 (addresses 0 to 15). Read_block commands issued with a block address above 15 will not be interpreted and the SRI512 will not return any response, except for the System area located at address 255. The SRI512 must have received a Select() command and be switched to Selected state before any Read_block() command can be accepted. All Read_block() commands sent to the SRI512 before a Select() command is issued are ignored. Figure 41. Read_block request format SOF Read_block 08h Address 8 bIts CRCL 8 bits CRCH 8 bits EOF AI07684b Request parameter: ● Address: block addresses from 0 to 15, or 255 Figure 42. Read_block response format SOF Data 1 8 bIts Data 2 8 bIts Data 3 8 bIts Data 4 8 bIts CRCL 8 bits CRCH 8 bIts EOF AI07685b Response parameters: ● ● ● ● Data 1: Less significant data byte Data 2: Data byte Data 3: Data byte Data 4: Most significant data byte Figure 43. Read_block frame exchange between reader and SRI512 Reader SOF SRI512 08h ADDR CRCL CRCH EOF SOF Data 1 Data 2 Data 3 Data 4 CRCL CRCH EOF AI10948b 35/47 SRI512 commands SRI512 8.8 Write_block (Addr, Data) command Command code = 09h On receiving the Write_block command, the SRI512 writes the 4 bytes contained in the command to the addressed block, provided that the block is available and not writeprotected. Data bytes are transmitted with the least significant byte first, and each byte is transmitted with the least significant bit first. The address byte gives access to the 16 blocks of the SRI512 (addresses 0 to 15). Write_block commands issued with a block address above 15 will not be interpreted and the SRI512 will not return any response, except for the System area located at address 255. The result of the Write_block command is submitted to the addressed block. See the following paragraphs for a complete description of the Write_block command: ● ● ● Figure 12: Resettable OTP area (addresses 0 to 4). Figure 15: Binary counter (addresses 5 to 6). Figure 17: EEPROM (addresses 7 to 15). The Write_block command does not give rise to a response from the SRI512. The reader must check after the programming time, tW, that the data was correctly programmed. The SRI512 must have received a Select() command and be switched to Selected state before any Write_block command can be accepted. All Write_block commands sent to the SRI512 before a Select() command is issued, are ignored. Figure 44. Write_block request format SOF Write_block Address 8 bIts Data 1 8 bIts Data 2 8 bIts Data 3 8 bIts Data 4 8 bIts CRCL 8 bits CRCH 8 bIts EOF 09h AI07687b Request parameters: ● ● ● ● ● Address: block addresses from 0 to 15, or 255 Data 1: Less significant data byte Data 2: Data byte Data 3: Data byte Data 4: Most significant data byte. Figure 45. Write_block response format No Response AI07680 36/47 SRI512 SRI512 commands Figure 46. Write_block frame exchange between reader and SRI512 Reader SRI512 SOF 09h Address Data 1 Data 2 Data 3 Data 4 CRCL CRCH EOF No response AI10949b 8.9 Get_UID() command Command code = 0Bh On receiving the Get_UID command, the SRI512 returns its 8 UID bytes. UID bytes are transmitted with the least significant byte first, and each byte is transmitted with the least significant bit first. The SRI512 must have received a Select() command and be switched to Selected state before any Get_UID() command can be accepted. All Get_UID() commands sent to the SRI512 before a Select() command is issued, are ignored. Figure 47. Get_UID request format SOF Get_UID 0Bh CRCL 8 bits CRCH 8 bits EOF AI07693b Request parameter: ● No parameter Figure 48. Get_UID response format UID 0 8 bits UID 1 8 bIts UID 2 8 bIts UID 3 8 bIts UID 4 8 bIts UID 5 8 bIts UID 6 8 bIts UID 7 8 bIts CRCL 8 bits CRCH 8 bIts AI07694 SOF EOF Response parameters: ● ● ● UID 0: Less significant UID byte UID 1 to UID 6: UID bytes UID 7: Most significant UID byte. 37/47 SRI512 commands SRI512 Unique Identifier (UID) Members of the SRI512 family are uniquely identified by a 64-bit Unique Identifier (UID). This is used for addressing each SRI512 device uniquely after the anticollision loop. The UID complies with ISO/IEC 15963 and ISO/IEC 7816-6. It is a read-only code, and comprises (as summarized in Figure 49): ● ● ● ● an 8-bit prefix, with the most significant bits set to D0h an 8-bit IC manufacturer code (ISO/IEC 7816-6/AM1) set to 02h (for STMicroelectronics) a 6-bit IC code set to 00 0110b = 6d for SRI512 a 42-bit unique serial number Figure 49. 64-bit unique identifier of the SRI512 Most significant bits 63 55 47 41 D0h 02h 6d Least significant bits 0 Unique Serial Number AI12375 Figure 50. Get_UID frame exchange between reader and SRI512 S E Reader O 0Bh CRCL CRCH O F F SRI512 S E O UID UID UID UID UID UID UID UID CRCL CRCH O 0 1 2 3 4 5 6 7 F F AI10950 8.10 Power-on state After power-on, the SRI512 is in the following state: ● ● ● ● It is in the low-power state. It is in Ready state. It shows highest impedance with respect to the reader antenna field. It will not respond to any command except Initiate(). 38/47 SRI512 Maximum rating 9 Maximum rating Stressing the device above the rating listed in the absolute maximum ratings table may cause permanent damage to the device. These are stress ratings only and operation of the device at these or any other conditions above those indicated in the operating sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Refer also to the STMicroelectronics SURE Program and other relevant quality documents. Table 6. Symbol TSTG tSTG ICC VMAX VESD Storage conditions Supply current on AC0 / AC1 Input voltage on AC0 / AC1 Electrostatic discharge voltage Machine model (1) Absolute maximum ratings Parameter Wafer (kept in its antistatic bag) Min. 15 Max. 25 23 –20 –7 –100 –1000 20 7 100 1000 Unit °C months mA V V V Human body model(1) 1. Mil. Std. 883 - Method 3015 39/47 DC and AC parameters SRI512 10 DC and AC parameters Table 7. Symbol TA Operating conditions Parameter Ambient operating temperature Min. –20 Max. 85 Unit °C Table 8. Symbol VCC ICC ICC VRET CTUN DC characteristics Parameter Regulated voltage Supply current (active in read) Supply current (active in write) Backscattering-induced voltage Internal tuning capacitor VCC = 3.0 V VCC = 3.0 V ISO 10373-6 13.56 MHz 20 64 Condition Min 2.5 Typ Max 3.5 100 250 Unit V µA µA mV pF Table 9. Symbol fCC AC characteristics(1) Parameter External RF signal frequency MI=(A-B)/(A+B) Condition Min Max Unit MHz % µs µs +2 µs ms 847.5 151 151 132 0 0 3 5 7 57 kHz µs µs µs µs µs ms ms ms 13.553 13.567 8 0.8 ETU = 128/fCC Coupler to SRI512 –2 5 fCC/16 128/fS 128/fS 14 ETU Coupler to SRI512 SRI512 to coupler With no auto-erase cycle (OTP) 9.44 14 2.5 MICARRIER Carrier modulation Index tRFR, tRFF tRFSBL tJIT tMIN CD fS t0 t1 t2 tDR tDA 10% rise and fall times Minimum pulse width for start bit ASK modulation data jitter Minimum time from carrier generation to first data Subcarrier frequency Antenna reversal delay Synchronization delay Answer to new request delay Time between request characters Time between answer characters tW Programming time for write With auto-erase cycle (EEPROM) Binary counter decrement 1. All timing measurements were performed on a reference antenna with the following characteristics: External size: 75 mm x 48 mm Number of turns: 3 Width of conductor: 1 mm Space between 2 conductors: 0.4 mm Value of the coil: 1.4 µH Tuning Frequency: 14.4 MHz. 40/47 SRI512 Figure 51. SRI512 synchronous timing, transmit and receive ASK Modulated signal from the Reader to the Contactless device DC and AC parameters A B tRFF tRFR ƒcc tRFSBL tMIN CD FRAME Transmission between the reader and the contactless device tDR tDR 1 0 DATA 1 EOF FRAME Transmitted by the reader in ASK FRAME Transmitted by the SRI512 in BPSK t0 847KHz SOF 11 0 DATA 10 DATA 10 t1 tDA tDA Data jitter on FRAME Transmitted by the reader in ASK tJIT tJIT tJIT tJIT tJIT 0 START tRFSBL tRFSBL tRFSBL tRFSBL tRFSBL Ai10951 41/47 Part numbering SRI512 11 Part numbering Table 10. Example: Ordering information scheme SRI512 – W4 / 1GE Device type SRI512 Package W4 = 180 µm ± 15 µm unsawn wafer SBN18 = 180 µm ± 15 µm bumped and sawn wafer on 8-inch frame Customer code 1GE = generic product xxx = customer code after personalization Note: Devices are shipped from the factory with the memory content bits erased to 1. For a list of available options (speed, package, etc.) or for further information on any aspect of this device, please contact your nearest ST sales office. 42/47 SRI512 ISO 14443 Type B CRC calculation Appendix A ISO 14443 Type B CRC calculation #include #include #include #include #define BYTE unsigned char #define USHORT unsigned short unsigned short UpdateCrc(BYTE ch, USHORT *lpwCrc) { ch = (ch^(BYTE)((*lpwCrc) & 0x00FF)); ch = (ch^(ch 8)^((USHORT)ch > 8) & 0xFF); return; } int main(void) { BYTE BuffCRC_B[10] = {0x0A, 0x12, 0x34, 0x56}, First, Second, i; printf("Crc-16 G(x) = x^16 + x^12 + x^5 + 1”); printf("CRC_B of [ "); for(i=0; i