m41st84w STMicroelectronics, m41st84w Datasheet
m41st84w
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m41st84w Summary of contents
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... Non-volatizes External LPSRAM – – – Battery Low flag Other Features Programmable Squarewave Generator (1Hz to 32KHz) –40°C to +85°C Operation Packaged in a 16-lead SOIC M41ST84W 2 3.0/3. Serial RTC with Supervisory Functions 16 1 SO16 (MQ) Automatically switches to back-up battery and deselects (write-protects) external ...
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... M41ST84W TABLE OF CONTENTS FEATURES SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Serial RTC Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Microprocessor Supervisory Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Figure 1. 16-pin SOIC Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 NVRAM Supervisory Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Other Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 SUMMARY DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Figure 2. Logic Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Table 1. Signal Names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Figure 3. 16-pin SOIC Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Figure 4. Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Figure 5. Hardware Hookup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 OPERATING MODES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 2-Wire Bus Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Figure 6 ...
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... Figure 19.Power Down/Up Mode AC Waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Table 14. Power Down/Up AC Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 PACKAGE MECHANICAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Figure 20.SO16 – 16-lead Plastic Small Outline, Package Outline . . . . . . . . . . . . . . . . . . . . . . . . . 26 Table 15. SO16 – 16-lead Plastic Small Outline, Package Mechanical Data . . . . . . . . . . . . . . . . . 26 PART NUMBERING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Table 16. Ordering Information Scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 REVISION HISTORY Table 17. Document Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 M41ST84W 3/29 ...
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... BCD format. Corrections for 28, 29 (leap year - valid until year 2100), 30 and 31 day months are made automatically. The M41ST84W is supplied in a 16-lead SOIC package. Table 1. Signal Names XI XO ...
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... IRQ/FT/OUT PFI 11 SQW 10 SCL 9 SDA REAL TIME CLOCK CALENDAR 44 BYTES USER RAM RTC w/ALARM & CALIBRATION WATCHDOG SQUARE WAVE COMPARE 2.5V COMPARE 2.5V COMPARE V PFD = 2.65V COMPARE AF IRQ/FT/OUT WDF SQW V INT BL POR RST PFO M41ST84W (1) (1) AI03931 5/29 ...
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... M41ST84W Figure 5. Hardware Hookup Regulator Unregulated V IN Voltage R1 R2 Note: 1. User-supplied crystal 6/29 M41ST84W IRQ/FT/OUT XI 32KHz (1) XTAL XO SDA SCL WDI RSTIN V BAT PFI INT RST To RST SQW To LED Display To NMI PFO AI03680 ...
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... OPERATING MODES The M41ST84W clock operates as a slave device on the serial bus. Access is obtained by imple- menting a start condition followed by the correct slave address (D0h). The 64 bytes contained in the device can then be accessed sequentially in the following order: 1. Tenths/Hundredths of a Second Register 2. Seconds Register 3 ...
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... M41ST84W Figure 6. Serial Bus Data Transfer Sequence CLOCK DATA START CONDITION Figure 7. Acknowledgement Sequence START SCLK FROM MASTER DATA OUTPUT BY TRANSMITTER DATA OUTPUT BY RECEIVER 8/29 DATA LINE STABLE DATA VALID CHANGE OF DATA ALLOWED 1 2 MSB STOP CONDITION AI00587 CLOCK PULSE FOR ACKNOWLEDGEMENT ...
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... Transmitter must internally provide a hold time to bridge the undefined region (300ns max) of the falling edge of SCL. tHD:STA tR tF tHIGH tSU:DAT tLOW tHD:DAT (1) Parameter = –40 to 85° 2.7 to 3.6V (except where noted M41ST84W tHD:STA tSU:STA tSU:STO SR P AI00589 Min Max Unit 0 400 kHz 1.3 µ ...
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... M41ST84W READ Mode In this mode the master reads the M41ST84W slave after setting the slave address (see 9., page 10). Following the WRITE Mode Control Bit (R/W=0) and the Acknowledge Bit, the word address ‘An’ is written to the on-chip address pointer. Next the START condition and slave ad- dress are repeated followed by the READ Mode Control Bit (R/W=1) ...
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... Figure 10. READ Mode Sequence BUS ACTIVITY: MASTER SDA LINE S BUS ACTIVITY: SLAVE ADDRESS DATA n+X Figure 11. Alternate READ Mode Sequence BUS ACTIVITY: MASTER SDA LINE S BUS ACTIVITY: SLAVE ADDRESS WORD S ADDRESS (An) SLAVE ADDRESS P DATA n DATA n+1 M41ST84W DATA n DATA n+1 AI00899 DATA n+X P AI00895 11/29 ...
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... The data word to be written to the memory is strobed in next and the internal address pointer is incremented to the next memory location within the RAM on the reception of an acknowledge clock. The M41ST84W slave receiver will send an acknowledge clock to the master transmitter after it has received the slave address (see 9., page 10) and again after it has received the word address and each data byte ...
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... Application Note AN1572. ® TIMEKEEPER Registers The M41ST84W offers 12 additional internal reg- isters which contain the Alarm, Watchdog, Flag, Square Wave and Control data. These registers are memory locations which contain external (user accessible) and internal copies of the data (usually ...
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... M41ST84W ® Table 3. 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 09h WDS BMB4 BMB3 0Ah AFE SQWE ABE 0Bh RPT4 RPT5 0Ch RPT3 ...
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... Calibrating the Clock The M41ST84W is driven by a quartz controlled oscillator with a nominal frequency of 32,768Hz. The devices are tested not exceed +/–35 ppm (parts per million) oscillator frequency error which equates to about +/–1.53 minutes per month. When the Calibration circuit is properly em- ployed, accuracy improves to better than ± ...
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... M41ST84W Figure 13. Crystal Accuracy Across Temperature Frequency (ppm –20 –40 –60 –80 –100 –120 –140 –160 –40 –30 –20 Figure 14. Clock Calibration NORMAL POSITIVE CALIBRATION NEGATIVE CALIBRATION 16/ – –0.036 ppm ± –10 ...
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... It can also be pro- grammed to go off while the M41ST84W is in the battery back-up to serve as a system wake-up call. Bits RPT5-RPT1 put the alarm in the repeat mode of operation ...
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... Note: Accuracy of timer is within ± the selected resolution. If the processor does not reset the timer within the specified period, the M41ST84W sets the WDF (Watchdog Flag) and generates a watchdog inter- rupt or a microprocessor reset. The most significant bit of the Watchdog Register is the Watchdog Steering Bit (WDS) ...
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... Square Wave Output The M41ST84W offers the user a programmable square wave function which is output on the SQW pin. The RS3-RS0 Bits located in 13h establish the square wave output frequency. These frequencies are listed in Table 5.. Once the selection of the Table 5. Square Wave Output Frequency ...
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... Pulse width less than 50ns will result in no RESET (for noise immunity). 3. Programmable (see Table 8., page 20/29 Reset Input (RSTIN) . The M41ST84W provides an independent input CC which can generate an output reset. The duration and function of this reset is identical to a reset gen- passes V (max). ...
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... In order to insure data integrity during ), which is the time subsequent periods of battery back-up mode, the battery should be replaced. The battery may be re- placed while V The M41ST84W only monitors the battery when a and PFO SS nominal V cations which require extensive durations in the battery back-up mode should be powered-up peri- odically (at least once every few months) in order for this technique to be beneficial ...
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... M41ST84W Table 7. t Definitions rec t Bit (TR) REC Note: 1. Default Setting Table 8. Default Values Condition Initial Power-up (2) (Battery Attach) Subsequent Power-up (with (3) battery back-up) Note: 1. WDS, BMB0-BMB4, RB0, RB1. 2. State of other control bits undefined Unchanged MAXIMUM RATING Stressing the device above the rating listed in the “ ...
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... Input Rise and Fall Times Input Pulse Voltages Input and Output Timing Ref. Voltages Note: Output Hi-Z is defined as the point where data is no longer driven. Figure 18. AC Testing Input/Output Waveforms 0.8V CC 0.2V CC Note: 50pF for M41ST84W. Table 11. Capacitance Symbol C Input Capacitance IN (3) Input / Output Capacitance ...
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... Load Capacitance L Note: 1. Load capacitors are integrated within the M41ST84W. Circuit board layout considerations for the 32.768kHz crystal of minimum trace lengths and isolation from RF generating signals should be taken into account. 2. STMicroelectronics recommends the KDS DT-38: 1TA/1TC252E127, Tuning Fork Type (thru-hole) or the DMX-26S: 1TJS125FH2A212, (SMD) quartz crystal for industrial temperature operations ...
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... Rise Time CC Rise Time CC = –40 to 85° 2.7 to 3.6V (except where noted may result in deselection/write protection not occurring until 200µs after V F may cause corruption of RAM data. FB 22) M41ST84W tR tRB tREC RECOGNIZED VALID (PER CONTROL INPUT) AI03681 Min Typ Max 300 10 ...
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... M41ST84W PACKAGE MECHANICAL INFORMATION Figure 20. 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 1. 26/ Min. ...
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... Tubes (Not for New Design - Use ECOPACK Package, Tubes F = ECOPACK Package, Tape & Reel TR = Tape & Reel (Not for New Design - Use F) For other options, or for more information on any aspect of this device, please contact the ST Sales Office nearest you. M41ST V 2.70V PFD M41ST84W 84W 27/29 ...
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... M41ST84W REVISION HISTORY Table 17. Document Revision History Date Version August 2000 1.0 First Issue 24-Aug-00 1.2 Block Diagram added (Figure 4) 08-Sep-00 1.3 SO16 package measures change 18-Dec-00 2.0 Reformatted, TOC added, and PFI Input Leakage Current added (Table 12) Addition of t graphic (see Figure 4); change to DC and AC Characteristics, Order Information (Tables 12, 18-Jun-01 2 ...
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