UPD4991A NEC, UPD4991A Datasheet
UPD4991A
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UPD4991A Summary of contents
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PARALLEL I/O CALENDAR CLOCK The PD4991A is a CMOS integrated circuit that has the ability to input/output 4-bit parallel time data and calendar data to/from a microcomputer and includes an alarm function. Its reference oscillation frequency is 32.768 kHz. ...
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PIN CONFIGURATION (Top View PD4991ACX ...
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BLOCK DIAGRAM BUS DATA CONTROLLER BUS DATA PD4991A DECODER ADDRESS CONTROLLER BUS ADDRESS 3 ...
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PIN FUNCTION • WE ..................... Write control pin (input). The contents of the data bus are written to an address specified by the address bus at the rising edge of WE. • OE ..................... Read control pin (input). While OE ...
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ABSOLUTE MAXIMUM RATINGS (V PARAMETER SYMBOL Supply Voltage V PP Input Voltage Range V IN Output Pin Breakdown Voltage V OUT Low-Level Output Current I OUT (N-ch open-drain) Operating Ambient Temperature T opt Storage Temperature T stg ELECTRICAL CHARACTERISTICS (V ...
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Write Cycle (V = 2 PARAMETER SYMBOL MIN. Cycle Time t WC CS-WE Reset Time t CW Address-WE Reset Time t AW Address-WE Setup Time t AS Write Pulse Width t WP Address Hold ...
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Write cycle timing 1 ADDRESS OHZ D OUT D IN Write cycle timing 2 ( ADDRESS OUT ...
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READ CYCLE (Unless otherwise specified, V PARAMETER SYMBOL MIN. Cycle Time t RC Address Access Time t AA CS-Access Time t ACS OE-Output Delay Time t OE OE-Output Delay Time t OLZ OE-Output Delay Time t OHZ Output Hold Time ...
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Read cycle timing 1 CS ADDRESS OE D OUT Read cycle timing 2 ADDRESS OUT Output Data t OLZ ACS t t CLZ OHZ Output Data PD4991A t ...
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FUNCTION SPECIFICATIONS • Reference frequency (X’tal OSC) ........... 32.768 kHz • Data format .............................................. BCD format • Data function Year, month, day, date, hour, minute, and second counters Leap year and months are automatically identified. Leap year is identified every ...
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FUNCTION OUTLINE • The PD4991A has the following three modes: 1 BASIC TIME MODE In this mode, data can be written and read between the timer counter and the CPU. Moreover, control registers 1 and 2 can be specified by ...
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Table 1 Correspondence between Mode Data and Modes ADDRESS = ( DATA MSB LSB BASIC TIME MODE ALARM SET & ALARM SET & TP ...
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MODE DESCRIPTION 1. BASIC TIME MODE (MODE = • Thirteen types of counters are provided: 10-year, 1-year, 10-month, 1-month, 10-day, 1-day, date, 10-hour, 1- hour, 10-minute, 1-minute, 10-second, and 1-second. • Date codes are 00H ...
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Table 3 Data Correspondence Table 1 CONTROL REGISTER1 (TIME COUNTER CONTROL) ADDRESS = ( W/O 0 NOP 1 CLOCK WAIT *1. ADJUST (+/–)30 s Second digit (second (second) ...
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ALARM SET & TP CONTROL MODE (MODE = ALARM SET & TP CONTROL MODE (MODE = (1) Setting time to alarm register The alarm register consists of a total ...
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Table 5 Address Correspondence Table 2 ALARM SET & TP CONTROL MODE (MODE = ALARM SET & TP CONTROL MODE (MODE = ADDRESS MSB LSB 1-second ...
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Table 6 Data Correspondence Table 3 TP FUNCTION CONTROL 1 (MODE = ADDRESS = DATA MSB LSB * 2048 1024 ...
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Selecting 12-/24-hour mode In the 12-hour mode, the second significant bit of the data for the 10-hour digit are used as an AM/PM flag 00 01** Select the 12- or 24-hour mode before setting the ...
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Table 9 Data Correspondence Table 6 Leap year counter (MODE = ADDRESS = R/W * Example Write 3 to 10-year digit Write 6 to 1-year digit Write 4 to 10-year digit ...
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The output signal of TP goes from “H” to “L” when the value of the alarm register coincides with the contents 1 of the time counter. Fig. 2 “H” Alarm coincidence • • Alarm coincidence flag, ...
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Fig Without RESET of the alarm coincidence flag 2048 Alarm coincidence 1 pulse Alarm coincidence "H" "L" Alarm coincidence Figs. 5 and 6 show examples of applications using TP Fig 2048 ...
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Fig 2048 ALARM ENABLE Alarm does not Alarm coincidence flag reset coincide Output status enabled Alarm coincidence 1 pulse 30.5 s "H" "L" Alarm coincidence flag ON TP SET (MODE = 0 * ...
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BUSY output The BUSY signal can be output to the TP When output of the BUSY signal is specified, only the BUSY signal is output to the TP The contents of the CONTROL REGISTER 2 are not affected, ...
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Oscillation characteristics Figs. 11 and 12 show the frequency stability when the ambient temperature (T changed with a crystal of crystal impedance C The stability and day difference are calculated by the following expressions: f – f reference ...
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Fig. 13 Dynamic Current Consumption Characteristics 1.0 Differences between PD4991 and PD4991A The PD4991A improves on the characteristics of the PD4991. These two products differ as follows: 1. Specifications PARAMETER SYMBOL Current Consumption Current ...
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AC Timing of PD4991 Timing of PD4991A Function PARAMETER Valid Range ADJUST BUSY Flag when 30 s ADJUST D ...
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Example of an Application Circuit 10 k ADDRESS DECODER WR RD 1SS53 2SA1175 + 510 1SS53 1 k Ni-Cd 4.7 k 3.6 V 2SC2785 GND The application circuits and their parameters are for references only and are ...
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PLASTIC DIP (300 mil NOTES 1) Each lead centerline is located within 0.25 mm (0.01 inch) of its true position (T.P.) at maximum material condition. 2) ltem "K" to center ...
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PIN PLASTIC SOP (300 mil NOTE Each lead centerline is located within 0.12 mm (0.005 inch) of its true position (T.P.) at maximum material condition PD4991A detail of ...
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RECOMMENDED SOLDERING CONDITIONS The following conditions must be met when soldering this product. Please consult with our sales offices when using other soldering process or under different conditions. Type of Surface Mounting Device PD4991 AGS Soldering process Infrared ray reflow ...
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PD4991A 31 ...
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... Specific: Aircrafts, aerospace equipment, submersible repeaters, nuclear reactor control systems, life support systems or medical equipment for life support, etc. The quality grade of NEC devices is "Standard" unless otherwise specified in NEC's Data Sheets or Data Books. If customers intend to use NEC devices for applications other than those specified for Standard quality grade, they should contact an NEC sales representative in advance ...