Rainbow-electronics DS2417 Manual do Utilizador

1 of 15 111901FEATURES§ Real-time clock (RTC) with fully compatible1-Wire® MicroLAN interface§ Uses the same binary time/date representationas the D

DS241710 of 151–WIRE SIGNALINGThe DS2417 requires strict protocols to ensure data integrity. The protocol consists of four types of sig-naling on one

DS241711 of 15READ/WRITE TIMING DIAGRAM Figure 9Write-one Time Slot15µs(OD: 2µs)60µs(OD: 6µs)DS2417Sampling WindowVPULLUPVPULLUP MINVIH MINVIL MAX0VtS

DS241712 of 15READ/WRITE TIMING DIAGRAM (continued) Figure 9Read-data Time SlotRESISTORMASTERDS2417MasterSampling Window60 µs £ tSLOT < 120 µs1 µs

DS241713 of 15INTERRUPT TIMING Figure 11Time= 122 µstINTERVALtPULSEtLATENCYVINTCase A: Latency < 0.5tINTERVALCase B: 0 < Latency < tINTERVALT

DS241714 of 15ABSOLUTE MAXIMUM RATINGS*Voltage on 1-Wire to Ground -0.5V to +7.0VOperating Temperature Range -40°C to +85°CStorage Temperature Range -

DS241715 of 15NOTES:1. All voltages are referenced to ground.2. Measured with outputs open.3. VPUP = external pullup voltage.4. Input load is to g

DS24172 of 15is successfully executed, the real-time clock functions become accessible and the master may thenprovide one of the real-time clock funct

DS24173 of 1564-bit ROM and ROM Function Control section allow the DS2417 to operate as a 1-Wire device andfollow the 1-Wire protocol detailed in the

DS24174 of 15TIMEKEEPINGA 32.768kHz crystal oscillator is used as the time base for the real-time clock counter. The oscillator canbe turned on or of

DS24175 of 15REAL-TIME CLOCKThe real-time clock is a 32-bit binary counter. It is incremented once per second. The real-time clockcan accumulate 136

DS24176 of 15CLOCK FUNCTION COMMAND FLOW CHART Figure 5Master TX ControlFunction Command66HRead Clock?YNBus MasterTX Reset?NYNBus MasterTX Reset?DS241

DS24177 of 15HARDWARE CONFIGURATION Figure 6RXTXOpen Drain Port Pin5 µATyp.DS2417 1-WIRE PORTRX = RECEIVETX = TRANSMITBUS MASTERVPUPDATARXTXMOSFET100

DS24178 of 15INITIALIZATIONAll transactions on the 1-Wire bus begin with an initialization sequence. The initialization sequence con-sists of a reset

DS24179 of 15ROM FUNCTIONS FLOW CHART Figure 7F0HSearch ROMCommand?DS2417 TX Bit 0DS2417 TX Bit 0Master TX Bit 0Bit 0Match ?DS2417 TX Bit 1DS2417 TX