M41ST84WMH1 STMICROELECTRONICS [STMicroelectronics], M41ST84WMH1 Datasheet
M41ST84WMH1
Related parts for M41ST84WMH1
M41ST84WMH1 Summary of contents
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FEATURES SUMMARY 5.0 OR 3.0V OPERATING VOLTAGE SERIAL INTERFACE SUPPORTS I (400 KHz) OPTIMIZED FOR MINIMAL INTERCONNECT TO MCU 2.5 TO 5.5V OSCILLATOR OPERATING VOLTAGE AUTOMATIC SWITCH-OVER and DESELECT CIRCUITRY CHOICE OF POWER-FAIL DESELECT VOLTAGES: – M41ST84Y 4.5 ...
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M41ST84Y, M41ST84W TABLE OF CONTENTS SUMMARY DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...
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Setting Alarm Clock Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...
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M41ST84Y, M41ST84W SUMMARY DESCRIPTION The M41ST84Y/W Serial supervisory TIMEKEEP- ® ER SRAM is a low power 512-bit static CMOS SRAM organized as 64 words by 8 bits. A built-in 32.768 kHz oscillator (external crystal controlled) and 8 bytes of the ...
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Figure 4. 16-pin SOIC Connections RST 3 WDI 4 M41ST84Y M41ST84W RSTIN 5 PFO 6 V BAT AI03678 Figure 6. Block Diagram SDA INTERFACE SCL 32KHz Crystal OSCILLATOR WDI ...
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M41ST84Y, M41ST84W Figure 7. Hardware Hookup Regulator Unregulated V IN Voltage R1 R2 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 ...
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DC AND AC PARAMETERS This section summarizes the operating and mea- surement conditions, as well as the DC and AC characteristics of the device. The parameters in the following DC and AC Characteristic tables are derived from tests performed under ...
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M41ST84Y, M41ST84W Table 5. DC Characteristics Sym Parameter Battery Current OSC ON I BAT Battery Current OSC OFF I Supply Current CC1 Supply Current I CC2 (Standby) Input Leakage Current ( Input Leakage Current (PFI) Output Leakage (3) ...
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OPERATING MODES The M41ST84Y/W clock operates as a slave de- vice on the serial bus. Access is obtained by im- plementing a start condition followed by the correct slave address (D0h). The 64 bytes con- tained in the device can ...
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M41ST84Y, M41ST84W Figure 9. Serial Bus Data Transfer Sequence CLOCK DATA START CONDITION Figure 10. Acknowledgement Sequence START SCLK FROM MASTER DATA OUTPUT BY TRANSMITTER DATA OUTPUT BY RECEIVER Figure 11. Bus Timing Requirements Sequence SDA tBUF SCL P S ...
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Table 7. AC Characteristics Symbol f SCL Clock Frequency SCL t Time the bus must be free before a new transmission can start BUF t SDA and SCL Fall Time F (2) Data Hold Time t HD:DAT START Condition Hold ...
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M41ST84Y, M41ST84W READ Mode In this mode the master reads the M41ST84Y/W slave after setting the slave address (see Figure 12, page 12). Following the WRITE Mode Control Bit (R/W=0) and the Acknowledge Bit, the word address ‘An’ is written ...
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Figure 14. Alternate READ Mode Sequence BUS ACTIVITY: MASTER SDA LINE S BUS ACTIVITY: SLAVE ADDRESS WRITE Mode In this mode the master transmitter transmits to the M41ST84Y/W slave receiver. Bus protocol is shown in Figure 15, page 13. Following ...
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M41ST84Y, M41ST84W Data Retention Mode With valid V applied, the M41ST84Y/W can be CC accessed as described above with READ or WRITE cycles. Should the supply voltage decay, the M41ST84Y/W will automatically deselect, write protecting itself when V V (max) ...
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CLOCK OPERATION The eight byte clock register (see Table 9, page 16) is used to both set the clock and to read the date and time from the clock binary coded decimal format. Tenths/Hundredths of Seconds, Seconds, Minutes, ...
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M41ST84Y, M41ST84W ® Table 9. TIMEKEEPER Register Map Address D7 D6 00h 0.1 Seconds 01h ST 10 Seconds 02h 0 10 Minutes 03h CEB CB 04h TR 0 05h 0 0 06h 0 0 07h 10 Years 08h OUT FT ...
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Calibrating the Clock The M41ST84Y/W is driven by a quartz controlled oscillator with a nominal frequency of 32,768 Hz. The devices are tested not exceed +/–35 PPM (parts per million) oscillator frequency error which equates to ...
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M41ST84Y, M41ST84W Setting Alarm Clock Registers Address locations 0Ah-0Eh contain the alarm set- tings. The alarm can be configured to go off at a prescribed time on a specific month, date, hour, minute, or second, or repeat every year, month, ...
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Figure 18. Back-Up Mode Alarm Waveform PFD V SO ABE, AFE Bits in Interrupt Register AF bit in Flags Register IRQ/FT/OUT Watchdog Timer The watchdog timer can be used to detect an out- of-control microprocessor. The user ...
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M41ST84Y, M41ST84W Square Wave Output The M41ST84Y/W offers the user a programma- ble square wave function which is output on the SQW pin. The RS3-RS0 Bits located in 13h estab- lish the square wave output frequency. These fre- quencies are ...
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Power-on Reset The M41ST84Y/W continuously monitors V When V falls to the power fail detect trip point, CC the RST pulls low (open drain) and remains low on power-up for t after V REC CC The RST pin is an ...
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M41ST84Y, M41ST84W Power-fail INPUT/OUTPUT The Power-Fail Input (PFI) is compared to an in- ternal reference voltage (1.25V). If PFI is less than the power-fail threshold (V PFI Output (PFO) will go low. This function is intended for use as an ...
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Table 13. t Definitions REC t Bit (TR) REC Note: 1. Default Setting Table 14. Default Values Condition Initial Power-up (2) (Battery Attach for SNAPHAT) Subsequent Power-up (with (3) battery back-up) Note: 1. WDS, BMB0-BMB4, RB0, RB1. ...
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M41ST84Y, M41ST84W Figure 20. Crystal Accuracy Across Temperature Frequency (ppm –20 –40 –60 –80 –100 –120 –140 –160 –40 –30 –20 Figure 21. Clock Calibration NORMAL POSITIVE CALIBRATION NEGATIVE CALIBRATION 24/ -0.038 ppm ...
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PACKAGE MECHANICAL INFORMATION Figure 22. SO16 – 16-lead Plastic Small Outline, Package Outline SO-b Note: Drawing is not to scale. Table 15. SO16 – 16-lead Plastic Small Outline, Package Mechanical Data Symbol Typ ...
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M41ST84Y, M41ST84W Figure 23. SOH28 – 28-lead Plastic Small Outline, Battery SNAPHAT, Package Outline SOH-A Note: Drawing is not to scale. Table 16. SOH28 – 28-lead Plastic Small Outline, battery SNAPHAT, Package Mechanical Data Symbol ...
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Figure 24. SH – 4-pin SNAPHAT Housing for 48mAh Battery & Crystal, Package Outline Note: Drawing is not to scale. Table 17. SH – 4-pin SNAPHAT Housing for 48mAh Battery & Crystal, Package Mechanical Data Symbol Typ ...
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M41ST84Y, M41ST84W Figure 25. SH – 4-pin SNAPHAT Housing for 120mAh Battery & Crystal, Package Outline Note: Drawing is not to scale. Table 18. SH – 4-pin SNAPHAT Housing for 120mAh Battery & Crystal, Package Mechanical Data Symbol Typ A ...
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PART NUMBERING Table 19. Ordering Information Scheme Example: Device Type M41ST Supply Voltage and Write Protect Voltage 84Y = V = 4.5 to 5.5V; 4.20V CC 84W = V = 2.7 to 3.6V; 2.55V CC Package MQ = SO16 (1,2) ...
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M41ST84Y, M41ST84W REVISION HISTORY Table 21. Document Revision History Date Rev. # August 2000 1.0 First Issue 24-Aug-00 1.2 Block Diagram added (Figure 6) 08-Sep-00 1.3 SO16 package measures change 18-Dec-00 2.0 Reformatted, TOC added, and PFI Input Leakage Current ...
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M41ST84, M41ST84Y, M41ST84W, 41ST84, ST84, SUPERVISOR, SUPERVISOR, SUPERVISOR, SUPERVISOR, SUPERVISOR, SU- PERVISOR, SUPERVISOR, SUPERVISOR, SUPERVISOR, SUPERVISOR, SUPERVISOR, SUPERVISOR, SUPERVISOR, SUPERVI- SOR, SUPERVISOR, SUPERVISOR, SUPERVISOR, SUPERVISOR, SUPERVISOR, Serial, Serial, Serial, Serial, Serial, Serial, Serial, Serial, Serial, Serial, Serial, Serial, Serial, Serial, ...