Rainbow-electronics DS1680 Manual do Utilizador

1 of 23 110901 FEATURES § Real-time clock (RTC) − Counts seconds, minutes, hours, date, month, day of the week, and year with leap-year

DS1680 10 of 23 MICROPROCESSOR MONITOR The DS1680 monitors three vital conditions for a microprocessor: power supply, software execution, and exte

DS1680 11 of 23 RESISTIVE TOUCH SCREEN (4-WIRE) Resistive touch screens consist of two resistive plates that are separated by a small gap. Each pl

DS1680 12 of 23 PROGRAMMABLE DUTY CYCLE The current required to take an X or Y measurement is VAVD / RD. In the case of RD = 250O and VAVD = 5V,

DS1680 13 of 23 CONVERSION TIMING Figure 7a PEN_OFFPD A0 A1X YNEW_DATAPD PDPDPDPD X XXX Y Y YY A0A0 A1A1X - YMeasureA0 - A1MeasureA1A0PDPD PDPDAV

DS1680 14 of 23 CONVERT AND ANSELIN TIMING Figure 8 CONVERTmust be at least2 state cyclesANSELINCONVERTAIN0 conversion requestedANSELIN = 0must b

DS1680 15 of 23 PARALLEL INTERFACE The ADC output is available on the data bus at pins D0–D7. A logic 0 on COEN will enable data onto the data bu

DS1680 16 of 23 ABSOLUTE MAXIMUM RATINGS* Voltage Range on Any Pin Relative to Ground -0.3V to +7.0V Operating Temperature Range 0°C t

DS1680 17 of 23 DC ELECTRICAL CHARACTERISTICS (0°C to +70°C; VCC = 3.3V ± 10%) PARAMETER SYMBOL MIN TYP MAX UNITS NOTES Input Leakage

DS1680 18 of 23 3-WIRE INTERFACE CHARACTERISTICS (0°C to +70°C; VCC = 3.3V ± 10%) PARAMETER SYMBOL MIN TYP MAX UNITS NOTES Data to Cloc

DS1680 19 of 23 ADC CHARACTERISTICS (0°C to +70°C; VCC, VAVD = 3.3V ± 10%) PARAMETER SYMBOL MIN TYP MAX UNITS NOTES Resistance of Digitizer

DS1680 2 of 23 Automatic backup and write protection of an external SRAM is provided through the VCCO and CEO pins. The backup energy source used

DS1680 20 of 23 POWER-FAIL AND RESET CHARACTERISTICS (0ºC to +70ºC; VCC = 3.3V ± 10%) PARAMETER SYMBOL MIN TYP MAX UNITS N

DS1680 21 of 23 3-WIRE TIMING DIAGRAM: READ DATA Figure 10 3-WIRE TIMING DIAGRAM: WRITE DATA Figure 11 PUSHBUTTON RESET Figure 12

DS1680 22 of 23 VCC POWER-UP Figure 13 VCC POWER-DOWN Figure 14 POWER-FAIL WARNING Figure 15

DS1680 23 of 23 NOTES: 1. Logic 1 voltages are specified at VCC = 3.3V or 5.0V, VOH = VCC for capacitive loads. Exclude RST pin. 2. Logic 0 vo

DS1680 3 of 23 SIGNAL DESCRIPTIONS VCC, GND (Digital Supply and Digital Ground) – DC power to the RTC, watchdog, X and Y drivers, and power-switc

DS1680 4 of 23 AVD, AVS (ADC Supply and Ground) – Power supply and ground for the ADC. AIN0, AIN1 (Analog Inputs) – These pins are the analog inp

DS1680 5 of 23 3-WIRE SERIAL INTERFACE Communication with the RTC and watchdog is accomplished through a simple 3-wire interface consisting of the

DS1680 6 of 23 ADDRESS/COMMAND BYTE Figure 4 shows the command byte for the DS1680. Each data transfer is initiated by a command byte. Bits 0–6 sp

DS1680 7 of 23 CLOCK, CALENDAR, AND ALARM The time and calendar information is accessed by reading/writing the appropriate register bytes. Note th

DS1680 8 of 23 AIE (Alarm Interrupt Enable) – When set to a logic 1, this bit permits the interrupt request flag (IRQF) bit in the status register

DS1680 9 of 23 POWER-FAIL COMPARATOR Figure 6 DS1680 V CC GND PFO PFI +5V C1 R1 VIN R2 R3 to µP V TRIP = 1.25 V H = 1.25 / R2||R3 R1 + R2||R3