M48T86PC1E STMICROELECTRONICS [STMicroelectronics], M48T86PC1E Datasheet
M48T86PC1E
Related parts for M48T86PC1E
M48T86PC1E Summary of contents
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Features ■ Drop-in replacement for PC computer clock/calendar ■ Counts seconds, minutes, hours, days, day of the week, date, month, and year with leap year compensation ■ Clock accuracy better than 1 minute per month ■ Interfaced with software as ...
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Contents Summary description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...
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PIE: periodic interrupt enable ...
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List of tables Table 1. Signal names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...
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List of figures Figure 1. Logic diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...
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Summary description The M48T86 is an industry standard Real Time Clock (RTC). The M48T86 is composed of a lithium energy source, quartz crystal, write protection circuitry, and a 128-byte RAM array. This provides the user with a complete subsystem packaged ...
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Table 1. Signal names AD0-AD7 Multiplexed address/data bus E Chip enable input R/W WRITE enable input DS Data strobe input AS Address strobe input RST Reset Input RCL RAM clear input MOT Bus type select input SQW Square wave output ...
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Figure 3. 28-pin SOIC connections Figure 4. Block diagram BAT DS R/W AS AD0-AD7 8/ MOT AD0 5 AD1 6 AD2 7 M48T86 AD3 8 AD4 9 AD5 10 ...
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Operation The M48T86 clock is driven by a quartz-controlled oscillator with a nominal frequency of 32,768 Hz. The devices are tested not to exceed 23 ppm (parts per million) oscillator frequency error at 25°C, which equates to approximately ±1 minute ...
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MOT (mode select). The MOT pin offers the flexibility to choose between two bus types (see page 12). When connected left disconnected, Intel bus timing is selected. The pin has an internal pull-down resistance of approximately 20K ...
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R/W (READ/WRITE input). The R/W pin is used to latch data into the M48T86 and provides functionality similar other memory systems. Non-volatile RAM The 114 general-purpose non-volatile RAM bytes are not dedicated to any special function within ...
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Figure 7. Motorola bus READ/WRITE mode AC waveforms AS tDAS DS R/W E AD0-AD7 (Write) AD0-AD7 (Read) 12/36 tASW tASD tCYC tDSL tDSH tRWS tCS tAH tAS tAS tOD tAH tRWH tCH tDW tDHW tDHR AI01649 ...
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Table 2. AC characteristics Symbol Parameter t Cycle time CYC t Pulse width, data strobe low or R/W high DSL t Pulse width, data strobe high or R/W low DSH t R/W hold time RWH t R/W setup time RWS ...
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Clock operations Address map The address map of the M48T86 is shown in 10 bytes of RAM that contain the RTC time, calendar and alarm data, and 4 bytes which are used for control and status. All bytes can be ...
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Figure 8. Address map 0 14 CLOCK AND CONTROL BYTES STATUS REGISTERS 13 14 114 STORAGE REGISTERS BYTES 127 Table 3. Time, calendar, and alarm formats Address RTC Bytes 0 Seconds 1 Seconds alarm 2 Minutes 3 Minutes alarm Hours, ...
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Interrupts The RTC plus RAM includes three separate, fully automatic sources of interrupt (alarm, periodic, update-in-progress) available to a processor. The alarm interrupt can be programmed to occur at rates from once per second to once per day. The periodic ...
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Alarm interrupt The alarm interrupt provides the system processor with an interrupt when a match is made between the RTC's hours, minutes, and seconds bytes and the corresponding alarm bytes. The three alarm bytes can be used in two ways. ...
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The third method uses a periodic interrupt to determine if an update cycle is in progress. The UIP Bit is set ...
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Register A UIP update in progress The Update in Progress (UIP) Bit is a status flag that can be monitored. When the UIP Bit is '1,' the update transfer will soon occur (see will not occur for at least 244µs. ...
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Register B SET When the SET Bit is a '0,' the update transfer functions normally by advancing the counts once per second. When the SET Bit is written to a '1,' any update transfer is inhibited and the program may ...
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The 24/12 Control Bit establishes the format of the hours byte. A '1' indicates the 24-hour mode and a '0' indicates the 12-hour mode. This bit is READ/WRITE and is not affected by internal functions or RST. DSE: daylight ...
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PF: periodic interrupt flag The Periodic Interrupt Flag (PF “Read only” bit which is set to a '1' when an edge is detected on the selected tap of the divider chain. The RS3-RS0 bits establish the periodic rate. ...
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V bypass capacitors will be released as low going spikes are generated or energy will be absorbed when overshoots occur. A ceramic bypass capacitor value of 0.1µF (as shown in Figure ...
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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 and operation of the device at these or any other conditions above those ...
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DC and AC parameters This section summarizes the operating and measurement 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 the ...
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Figure 13. AC testing load circuit (with IRQ) Table 11. Capacitance Symbol C Input capacitance IN (3) C Input / output capacitance IO 1. Effective capacitance measured with power supply at 5V; sampled only, not 100% tested 25°C, ...
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Figure 14. Power down/up mode AC waveforms V CC 4.5V V PFD Table 13. Power down/up mode AC characteristics Symbol Parameter ( fall time rise time ...
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Figure 15. PCDIP24 – 24-pin plastic DIP, battery CAPHAT, package outline B1 Note: Drawing is not to scale. 28/ PCDIP ...
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Table 15. PCDIP24 – 24-pin plastic DIP, battery CAPHAT, package mechanical data Symb Typ Figure 16. SOH28 – 28-lead plastic small outline, 4-socket SNAPHAT, package outline B ...
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Table 16. SOH28 – 28-lead plastic small outline, 4-socket battery SNAPHAT, package mechanical data Symb Typ 1. Figure 17. SH – 4-pin SNAPHAT housing for 48mAh ...
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Table 17. SH – 4-pin SNAPHAT housing for 48mAh battery and crystal, package mechanical data Symb Typ Figure 18. SH – 4-pin SNAPHAT housing for 120mAh battery and crystal, package ...
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Table 18. SH – 4-pin SNAPHAT housing for 120mAh battery and crystal, package mechanical data Symb Typ 32/36 mm Min Max Typ 10.54 8.00 8.51 7.24 8.00 0.38 0.46 0.56 ...
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Part numbering Table 19. Ordering information scheme Example: Device Type M48T Supply Voltage and Write Protect Voltage 4.5 to 5.5V Package PC = PCDIP24 ( SOH28 Temperature Range ...
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Table 20. SNAPHAT battery table Part Number M4T28-BR12SH M4T32-BR12SH 34/36 Description Lithium battery (48mAh) SNAPHAT Lithium battery (120mAh) SNAPHAT Package SH SH ...
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Revision history Table 21. Document revision history Date Revision Mar-1999 1.0 04-May-2000 1.1 31-Jul-2001 2.0 20-May-2002 2.1 01-Apr-2003 3.0 02-Apr-2004 4.0 20-Feb-2007 5.0 Changes First Issue Page layout changed Reformatted; temp/voltage info. added to tables Modify reflow time and temperature ...
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Information in this document is provided solely in connection with ST products. STMicroelectronics NV and its subsidiaries (“ST”) reserve the right to make changes, corrections, modifications or improvements, to this document, and the products and services described herein at any ...