ACR1255U-J1 – Reference Manual info@acs.com.hkVersion V1.07 www.acs.com.hkPage 4 of 77Table of Contents1.0. Introduction ............................................................................................................... 71.1. Symbols and Abbreviations ...................................................................................................72.0. Features ..................................................................................................................... 83.0. System Block Diagram ............................................................................................. 94.0. Hardware Design ..................................................................................................... 124.1. Battery..................................................................................................................................124.1.1. Battery Charging .........................................................................................................124.1.2. Battery Life ..................................................................................................................124.2. Bluetooth Interface...............................................................................................................124.3. USB Interface ......................................................................................................................124.3.1. Communication Parameters .......................................................................................124.3.2. Endpoints ....................................................................................................................134.4. NFC Interface ......................................................................................................................144.4.1. Carrier Frequency .......................................................................................................144.4.2. Card Polling.................................................................................................................144.5. User Interface ......................................................................................................................144.5.1. Keys ............................................................................................................................144.5.2. Mode Selection Switch ................................................................................................154.5.3. Status LED ..................................................................................................................154.5.4. Buzzer .........................................................................................................................165.0. Software Design ...................................................................................................... 175.1. Bluetooth Connection Flow ..................................................................................................175.2. Profile Selection ...................................................................................................................185.3. Authentication ......................................................................................................................195.4. Communication Profile.........................................................................................................205.5. Frame Format ......................................................................................................................205.5.1. Data Frame Format .....................................................................................................205.6. Bluetooth Communication Protocol .....................................................................................215.6.1. Card Power On ...........................................................................................................215.6.2. Card Power Off ...........................................................................................................225.6.3. Get Slot Status ............................................................................................................235.6.4. APDU Command.........................................................................................................245.6.5. Notify Card Status Command .....................................................................................265.6.6. Hardware Error Response ..........................................................................................265.6.7. Escape Command.......................................................................................................275.7. Mutual Authentication and Encryption Protocol ...................................................................285.7.1. Bluetooth Authentication Program Flow .....................................................................285.7.2. SPH_to_RDR_ReqAuth ..............................................................................................295.7.3. RDR_to_SPH_AuthRsp1 ............................................................................................305.7.4. SPH_to_RDR_AuthRsp ..............................................................................................315.7.5. RDR_to_SPH_AuthRsp2 ............................................................................................325.7.6. RDR_to_SPH_ACK (Error handling) ..........................................................................326.0. Host Programming (PC-linked) API ....................................................................... 346.1. PC/SC API ...........................................................................................................................346.1.1. SCardEstablishContext ...............................................................................................346.1.2. SCardListReaders .......................................................................................................346.1.3. SCardConnect.............................................................................................................346.1.4. SCardControl ..............................................................................................................346.1.5. SCardTransmit ............................................................................................................346.1.6. ScardDisconnect .........................................................................................................346.1.7. APDU Flow..................................................................................................................356.1.8. Escape Command Flow ..............................................................................................36