Intersil Corporation CDP1879C-1, CDP1879 Datasheet

CDP1879,

CDP1879C-1

March 1997

Features

• CPU Interface for Use with General-Purpose Microprocessors

• Time Of Day/Calendar

• Reads Seconds, Minutes, Hours

• Reads Day of Month and Month

• Alarm Circuit With Seconds, Minutes or Hours Operation

• Power Down Mode

• Separate Clock Output Selects 1 of 15 Square Wave Signals

• Interrupt Output Activated By Clock Output and/or Alarm Circuit

• Date Integrity Sampling for Clock Rollover Eliminated

• On-Board Oscillator:

- Crystal Operation CDP1879 at 10V. . . . . . . 4.19MHz,

2.09MHz or 1.048MHz

- Crystal Operation CDP1879C-1 at 5V . . . . . 4.19MHz,

2.09MHz or 1.048MHz or 32kHz

- External Clock Operation at 10V or 5V. . . . 4.19MHz,

2.09MHz, 1.048MHz or 32kHz

• Addressable in Memory Space or CDP1800 Series I/O Mode

• Low Standby (Timekeeping) Voltage with External Clock

• Related Literature

- AN7275, Guide to the Use of CD1879 and

CDP1879C1 Real Time Clock

Pinout

CDP1879, CDP1879C-1 (PDIP, SBDIP)

TOP VIEW

INT

RESET

POWER DOWN

MEM

IO/ TPB/

TPA

A2 A1 A0

1 2 3 4 5 6 7 8

9 10 11 12

XTAL

23 22

XTAL CLK

OUT DB7

DB6

DB5

DB4

DB3

DB2

DB1

DB0

CMOS Real-Time Clock

Description

The CDP1879 real-time clock supplies time and calendar information from seconds to months in BCD format. It consists of 5 separately addressable and programmable counters that divide down an oscillator input. The clock input can have any one of 4 possible frequencies, allowing ﬂexibility in the choice of crystal or external clock sources. Using an external 32kHz clock source, timekeeping can be performed down to 2.5V (see Standby (Timekeeping)Voltage Operation).

The device can be memory-mapped for use with any general-purpose microprocessor and has the additional capability of operating in the CDP1800 series input/output mode.

The real-time clock functions as a time-of-day/calendar with an alarm capability that can be set for combinations of seconds, minutes or hours. Alarm time is conﬁgured by loading alarm latches that activate an interrupt output through a comparator when the counter and alarm latch v alues are equal.

Fifteen selectable square-wave signals are available as a separate clock output signal and can also activate the interrupt output. A status register is available to indicate the interrupt source. The value in an 8 bit control register determines the operational characteristics of the de vice, by selecting the prescaler divisor and the clock output, and controls the load and alarm functions.

A transparent “freeze” circuit preclude clock rollover during counter and latch access times to assure stable and accurate values in the counters and alarm latches.

The CDP1879 is functionally identical to the CDP1879C-1. The CDP1879 has a recommended operating voltage range of 4V to 10.5V, and the CDP1879C-1 has a recommended operating voltage range of 4V to 6.5V . The CDP1879 and the CDP1879C-1 are supplied in 24 lead hermetic dual-in-line side-brazed ceramic packages (D sufﬁx) and 24 lead dual-in-line plastic packages (E sufﬁx

Ordering Information

TEMP

P A CKAGE

PDIP -40oC to

SBDIP -40oC to

Burn-In CDP1879CD1X - D24.6

RANGE 5V 10V

CDP1879CE1 CDP1879E E24.6

+85oC

CDP1879CD1 - D24.6

+85oC

CDP1879 Modes of Operation

OPERATION FUNCTION

Read 1. Seconds, minutes, hours, date and month counters

Write 1. Control register to set device operation

Power Down 1. Three-state interrupt output with active alarm or

Interrupt 1. Clock out as source

2. Status register to identify interrupt source

2. Seconds, minutes, hours, date and month counters

3. Alarm latches for alarm time

clock out circuitry for wake-up control

2. Data bus and address inputs are “DON’T CARE”

2. Alarm time as source

3. Either interrupt can occur during normal or power down mode

PKG.

NO.

CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. http://www.intersil.com or 407-727-9207

4-104

File Number

1360.2

CDP1879, CDP1879C-1

Absolute Maximum Ratings Thermal Information

DC Supply Voltage Range, V

(Voltage referenced to VSS Terminal)

CDP1879 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.5V to +11V

CDP1879C-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.5V to +7V

Input Voltage Range, All Inputs . . . . . . . . . . . . . . -0.5 to VDD +0.5V

DC Input Current, Any One Input . . . . . . . . . . . . . . . . . . . . . . ±10mA

Device Dissipation Per Output Transistor. . . . . . . . . . . . . . . . 40mW

For TA = Full Package Temperature Range

(All Package Types)

CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation of the device at these or any other conditions above those indicated in the operational sections of this speciﬁcation is not implied.

Thermal Resistance (Typical) θJA (oC/W) θJC (oC/W)

PDIP Package. . . . . . . . . . . . . . . . . . . 60 N/A

SBDIP Package. . . . . . . . . . . . . . . . . . 50 12

Operating Temperature Range (TA)

Package Type D, H . . . . . . . . . . . . . . . . . . . . . . .-55oC to +125oC

Package Type E. . . . . . . . . . . . . . . . . . . . . . . . . . .-40oC to +85oC

Storage Temperature Range (T

Lead Temperature (During Soldering). . . . . . . . . . . . . . . . . .+265oC

At Distance 1/16 ±1/32 in. (1.59± 0.79mm) From Case for 10s Max

). . . . . . . . . . . .-65oC to +150oC

STG

Operating Conditions at T

PARAMETER

DC Operating Voltage Range 4 10.5 4 6.5 V Input Voltage Range V DC Standby (Timekeeping) Voltage (Note 1), V

TA = -40oC to +85oC (Note 2) 3 - 3 - V TA = 0o to +70oC 2.5 - 2.5 V

Clock Input Rise or Fall Time, tR, t

VDD = 5V - 10 - 10 µs VDD = 10V - 1 - - µs

NOTES:

1. Timekeeping function only, no READ/WRITE accesses, 32kHz external frequency source only, no crystal operation.

2. See Standby (Timekeeping) Voltage Operation.

= FuIl Package-Temperature Range, Unless Otherwise speciﬁed. For maximum reliability, operating con-

ditions should be selected so that operation Is always within the following ranges:

LIMITS

CDP1879 CDPl879C-1

MIN MAX MIN MAX

STBY

UNITS

4-105

CDP1879, CDP1879C-1

XTAL

OSCILLATOR SECOND

XTAL

CLOCK OUT INT RESET

DB0-DB7 A0 A1 A2 TPA

MEM

I-O TPB/WR RD CS POWER DOWN

PRESCALE

SELECT

CLOCK AND

INT. LOGIC

INT. STATUS

I/O

INTERFACE

ADDRESS DECODE

AND

CONTROL LOGIC

FREEZE CIRCUIT

CONTROL REGISTER

CLOCK

SELECT

AM - PM

AND

HOUR LOGIC

MINUTE HOUR DAY MONTH

8-BIT DATA BUS

COMPARATOR

SECOND

LATCH

MINUTE

LATCH

HOUR

LATCH

CALENDAR

LOGIC

FIGURE 1. REAL-TIME CLOCK FUNCTIONAL DIAGRAM

TABLE 1.

CONTROL REGISTER BIT ASSIGNMENT

Bit 1, 0

Frequency 00

Select 01

10 11

32768Hz

1.048576MHz

2.097152MHz

4.194304MHz

Bit 2

Start/Stop 1 = Start

0 = Stop

Bit 3

Counter/Latch Control “0” = Write to Counter and disable alarm “1” = Write to and enable alarm Clock Select

Bit 7, 6, 5, 4

0000 - disableµs 0001 - 488.2µs 0010 - 976.5µs 0011 - 1953.1µs 0100 - 3906.2µs 0101 - 7812.5µs 0110 - 15.625ms 0111 - 31.25ms

1000 - 62.5ms 1001 - 125ms 1010 - 250ms 1011 - 500ms 1100 - sec. 1101 - min. 1110 - hour 1111 - day

TABLE 2.

ADDRESSES A2 A1 A0

Latch, Counter Seconds 0 1 0 Latch, Counter Minutes 0 1 1 Latch, Counter Hours 1 0 0 Counter, Day 1 0 1 Counter, Month 1 1 0 Control, Register 1 1 1 Status Register 1 1 1 MSB of Hours Counters (Bit 7) is an AM-PM Bit. 0 = AM; 1 = PM Bit 6 of Hours Counter Controls 12/24 hr. 1 = 12 Hr: 0 = 24 Hr. Status Register: Bit 7 MSB = Alarm

Interrupt Source: Bit 6 = Clock. MSB of Month Counter (Bit 7) is a Leap Year Bit 0 = No, 1 = Yes.

4-106

CDP1879, CDP1879C-1

Static Electrical Speciﬁcations at T

-40oC to +85oC VDD± 5%, Unless Otherwise Speciﬁed

CONDITIONS LIMITS

CDP1879 CDPl879C-1

PARAMETER

Ouiescent Device Current I

(V)

MIN

(NOTE 1)

TYP MAX MIN

(NOTE 1)

TYP MAX

0, 5 5 - 0.01 50 - 0.02 200 µA

0, 10 10 - 1 200 - - -

Output Low Drive (Sink) Current, Data Bus and INT l

Output High Drive (Source) Current, Data Bus and INT I

Output Low Drive (Sink) Current, Clock Out l

Output High Drive (Source) Current, Clock Out I

Output Low Drive (Sink) Current, XTAL Out l

Output High Drive (Source) Current, XTAL Out I

Output Voltage Low-Level V (Note 2)

Output Voltage High Level V (Note 2)

Input Low Voltage V

Input High Voltage V

Input Leakage Current I

Three-State Output Leakage Current I

OUT

0.4 0, 5 5 1.8 4 - - - -

0.5 0,10 10 3.6 7 - - - -

4.6 0, 5 5 -1.1 -2.3 - -1.1 -2.3 -

9.5 0,10 10 -2.6 -4.4 - - - -

0.4 0, 5 5 0.6 1.4 - 0.6 1.4 -

0.5 0,10 10 1.2 3 - - - -

4.6 0, 5 5 -1.1 -2.3 - -1.1 -2.3 -

9.5 0,10 10 -2.6 -4.4 - - - -

0.4 0, 5 5 0.2 0.9 - 0.2 0.9 -

0.5 0,10 10 0.4 2 - - - -

4.6 0, 5 5 -0.15 -0.4 - -0.15 -0.4 -

9.5 0,10 10 -0.3 -0.7 - - - -

- 0, 5 5 - 0 0.1 - 0 0.1

- 0,10 10 - 0 0.1 - - -

- 0, 5 5 4.9 5 - 4.9 5 -

- 0, 10 10 9.9 10 - - - -

0.5, 4.5

0.5, 9.5

0.5, 4.5

0.5, 9.5 Any

Input

0, 5

0, 10

3.5

1.5

±1 ±2

3.5

0, 5 0,5 5 - - ±1- - ±1

0,10 0,10 10 - - ±1--Operating Current (Note 3) External Clock 32kHz - - 5 - 0.01 0.15 - 0.01 0.15 External Clock 1MHz - - 5 - 0.2 1 - 0.2 1 External Clock 2MHz - - 5 - 0.35 1.5 - 0.35 1.5 External Clock 4MHz - - 5 - 0.7 2 - 0.7 2 External Clock 32kHz - - 10 - 0.03 0.25 - - External Clock 1MHz - - 10 - 0.4 2 - - External Clock 2MHz - - 10 - 0.8 3 - - External Clock 4MHz - - 10 - 1.6 4.5 - XTAL Oscillator (Note 4) 32kHz - - 5 - 0.1 0.25 - 0.1 0.25 XTAL Oscillator (Note 4) 1MHz - - 5 - 0.3 0.5 - 0.3 0.5 XTAL Oscillator (Note 4) 2MHz - - 5 - 0.4 0.6 - 0.4 0.6 XTAL Oscillator (Note 4) 4MHz - - 5 - 0.6 0.8 - 0.6 0.8 XTAL Oscillator (Note 4) 1MHz - - 10 - 1.6 3 - - XTAL Oscillator (Note 4) 2MHz - - 10 - 1.8 3.5 - - XTAL Oscillator (Note 4) 4MHz - - 10 - 2 5 - - -

UNITS

1.5

±1

µA

4-107

CDP1879, CDP1879C-1

Static Electrical Speciﬁcations at T

-40oC to +85oC VDD± 5%, Unless Otherwise Speciﬁed (Continued)

CONDITIONS LIMITS

PARAMETER

Input Capacitance C Output Capacitance C

IN OUT

Maximum Clock Rise tR, t and Fall Times

(V)

- - - - 5 7.5 - 5 7.5 pF

- - - - 10 15 - 10 15

--5--10--10µs

--10--1---

(V)

NOTES:

1. Typical values are for TA = 25oC and nominal VDD.

2. IOL = IOH = 1µA.

3. Operating current measured with clockout = 488.2µs and no load.

4. See Table 3 and Figure 6 for oscillator circuit information.

Programming Model

WRITE AND READ REGISTERS WRITE ONLY REGISTERS

BCD FORMAT DB7 DB0

TENS 0-5 UNITS 0-9

SECONDS COUNTER (00-59)

DB7 DB0

TENS 0-5

MINUTES COUNTER (00-59)

DB7 DB0

DB6

X X TENS 0-2

HOURS COUNTER (01 - 12 OR 00-23) DB7 0=AM, 1=PM DB6 0=24 HR, 1=12 HR

DB7 DB0

TENS 0-3 UNITS 0-9

DAY OF MONTH COUNTER (01-28, 29, 30, 31)

DB7 DB0

X TENS 0 OR 1

MONTH COUNTER (JAN=1 DEC=12) DB7 0=NO LEAP YEAR

1=LEAP YEAR

UNITS 0-9

CDP1879 CDPl879C-1

(NOTE 1)

MIN

TYP MAX MIN

DB7 DB0

6543210

CONTROL REGISTER DB0-DB1 - FREQUENCY SELECT

DB2 - START/STOP DB3 - COUNTER/ALARM LATCH CONTROL DB4-DB7 - CLOCK OUTPUT SELECT

DB7 DB0

TENS 0-5 UNITS 0-9

SECONDS ALARM LATCH (00-59)

DB7 DB0

TENS 0-5 UNITS 0-9

MINUTES ALARM LATCH (00-59)

DB6

DB7 DB0

TENS 0-2 UNITS 0-9XX

HOURS ALARM LATCH (01-12 OR 00-23 12 HR, DB7=0 AM, 1=PM 24 HR, DB7=X

(NOTE 1)

TYP MAX

READ ONLY REGISTER

DB7 DB0

DB6

X000000

UNITS

4-108

INTERRUPT STATUS REGISTER DB7=1 ALARM CIRCUIT ACTIVATED INT. DB6=1 CLOCK OUTPUT ACTIVATED

INT.

CDP1879, CDP1879C-1

ADDRESS ACTIVE SIGNAL

0 1 0 X - 0 Write Seconds Counter 0 1 0 - X 0 Read Seconds Counter 0 1 1 X - 0 Write Minutes Counter 0 1 1 - X 0 Read Minutes Counter 1 0 0 X - 0 Write Hours Counter 1 0 0 - X 0 Read Hours Counter 1 0 1 X - 0 Write Date Counter 1 0 1 - X 0 Read Date Counter 1 1 0 X - 0 Write Month Counter 1 1 0 - X 0 Read Month Counter 0 1 0 X - 1 Write Seconds Alarm Latch 0 1 1 X - 1 Write Minutes Alarm Latch 1 0 0 X - 1 Write Hours Alarm Latch 1 1 1 X - - Write Control Register

BIT 3 CONTROL

1 1 1 - X - Read Int. Status Register

General Operation

The real-time clock contains seconds, minutes, and hours, date and month counters that hold time of day/calendar information (see Figure 2). The frequency of an intrinsic oscillator is divided down to supply a once-a-second signal to the counter series string. The counters are separately addressable and can be written to or read from.

The real-time clock contains seconds, minutes and hour write-only alarm latches that store the alarm time (see Figure 3). When the value of the alarm latches and counters are equal, the interrupt output is activated. The interrupt output can also be activated by a clock output transition. The clock output is derived from the prescaler and counters and can be one of 15 square-wave signals. The value in the readonly interrupt status register identiﬁes the interrupt source.

Operational control of the real-time clock is determined by the byte in a write-only control register. The 8-bit v alue in this register determines the correct divisor for the prescaler, a data direction and alarm enable bit, clock output select, and start/stop control (see Figure 4).

Data transfer and addressing are accomplished in two modes of operation, memory mapping and I/O mapping using the CDP1800-series microprocessors. The mode is selected by the level on an input pin. (IO/ mapping implies use of the address lines as chip selects and address inputs during linear selection or partial or full decoding methods. I/O mapping with the CDP1800-series microprocessors involves use of the N line outputs in conjunction with input and output instructions to transfer data to and from memory.

MEM). Memory

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