Rainbow-electronics DS2705 Manual do Utilizador

1 of 18 050506 GENERAL DESCRIPTION The DS2705 provides the master side of a Secure Hash Algorithm (SHA) based token authentication scheme. Ha

DS2705: SHA-1 Authentication Master 10 of 18 MASTER PORT (MDQ) FUNCTION COMMANDS MASTER MODE WRITE CHALLENGE COMMAND Write Challenge [0Ch, XXXXXXXX

DS2705: SHA-1 Authentication Master 11 of 18 MAC Comparison After the SHA-1 computation is completed by the remote token, the DS2705 and remote SHA

DS2705: SHA-1 Authentication Master 12 of 18 Table 5. Configuration Register FIELD NAME DESCRIPTION DEFAULT CR[1:0] RTA1:0 Re-Tries Per Authenti

DS2705: SHA-1 Authentication Master 13 of 18 MEMORY The DS2705 has a 256 byte linear memory space for the EEPROM memory block that stores the chall

DS2705: SHA-1 Authentication Master 14 of 18 Figure 6. 1-Wire Bus Interface Circuitry, DS2705 as Slave Vpullup(2.5 to 5.5V)RxTxRxRx = ReceiveTx = T

DS2705: SHA-1 Authentication Master 15 of 18 Write Data [6Ch, XX]. This command writes data starting at memory address XX. The LSb of the data to b

DS2705: SHA-1 Authentication Master 16 of 18 Table 7. Slave Function Commands COMMAND DESCRIPTION COMMAND PROTOCOL BUS STATE AFTER COMMAND PROT

DS2705: SHA-1 Authentication Master 17 of 18 I/O SIGNALING The 1-Wire bus requires strict signaling protocols to ensure data integrity. The four pr

DS2705: SHA-1 Authentication Master 18 of 18 Figure 9. 1-Wire Write and Read-Time Slots WRITE 0 SLOT WRITE 1 SLOT tSLOT tLOW0 tSLOTtRECtLOW1VPULL

DS2705: SHA-1 Authentication Master 2 of 18 ABSOLUTE MAXIMUM RATINGS Voltage Range on All Pins (except VPP), Relative to VSS -0.3V to +5.5VVoltage

DS2705: SHA-1 Authentication Master 3 of 18 AC ELECTRICAL CHARACTERISTICS: MASTER 1-Wire INTERFACE (2.5V £ VDD £ 5.5V, TA = -20°C to +85°C.) PARAM

DS2705: SHA-1 Authentication Master 4 of 18 AC ELECTRICAL CHARACTERISTICS: SLAVE 1-Wire INTERFACE (2.5V £ VDD £ 5.5V, TA = -20°C to +85°C.) PARAME

DS2705: SHA-1 Authentication Master 5 of 18 AC ELECTRICAL CHARACTERISTICS (2.5V £ VDD £ 5.5V, TA = -20°C to +85°C.) PARAMETER SYMBOL CONDITIONS MI

DS2705: SHA-1 Authentication Master 6 of 18 Figure 1. Block Diagram EEPROM1-Wire Master/Slave160-bit MACControl FSM64-bit ChallengeCHALPASSPullup C

DS2705: SHA-1 Authentication Master 7 of 18 Figure 2. Typical Application Circuit DS2705CHALPASSFAILCharge CircuitCharge SupplyVSSMDQVDDSDQVPPChar

DS2705: SHA-1 Authentication Master 8 of 18 Table 1. Presence Detection/Authentication on Power-up Using CHAL Pin TIME FROM POWER UP CHAL PIN CHP

DS2705: SHA-1 Authentication Master 9 of 18 AUTHENTICATION SEQUENCE Following the detection of the battery, the DS2705 initiates the authentication