RICOH R2045S, R2045D Technical data

R2045S/D

4-wire Serial Interface Real Time Clock Module

NO.EA-113-100825

OUTLINE

The R2045S/D is a real-time clock module, built in CMOS real-time clock IC and crystal oscillator, connected to the CPU by four signal lines, CE, SCLK, SI, and SO, and configured to perform serial transmission of time and calendar data to the CPU. The oscillation frequency is adjusted to high precision (0±5ppm: 15sec. per month at 25°C) The periodic interrupt circuit is configured to generate interrupt signals with six selectable interrupts ranging from 0.5 seconds to 1 month. The 2 alarm interrupt circuits generate interrupt signals at preset times. As the oscillation circuit is driven under constant volt age, fluctuation of the oscillator frequency due to supply volt age is small, and the time keeping current is small (TYP. 0.48μA at 3V). The oscillation halt sensing circuit can be used to judge the validity of internal data in such events as power-on; The supply voltage monitoring circuit is configured to record a drop in supply voltage below two selectable supply voltage monitoring threshold settings. The 32-kHz clock output function (N-channel Open drain output) is intended to output sub-clock pulses for the external microcomputer. The oscillation adjustment circuit is intended to adjust time by correcting deviations in the oscillation frequency of the crystal oscillator.

FEATURES

• Built in 32.768kHz crystal unit, The oscillation frequency is adj usted to high precision (0±5ppm: at 25°C)

• Time keeping voltage 1.15V to 5.5V

• Super low power consumption 0.48μA TYP (1.2μA MAX) at V

• Four signal lines (CE, SCLK, SI, and SO) required for connection to the CPU.

• Time counters (counting hours, minutes, and seconds) and calendar counters (counting years, months,

days, and weeks) (in BCD format)

• Interrupt circuit configured to generate interrupt signals (with interrupts ranging from 0.5 seconds to 1 month) to the CPU and provided with an interrupt flag and an interrupt halt

• 2 alarm interrupt circuits (Alarm_W for week, hour, and minute alarm settings and Alarm_D for hour and minute alarm settings)

• 32768Hz clock output pin (N-channel open drain output)

• With Power-on flag to prove that the power supply starts from 0V

• With Oscillation halt sensing Flag to judge the validity of internal data

• Supply voltage monitoring circuit with two supply voltage monitoring threshold settings

• Automatic identification of leap years up to the year 2099

• Selectable 12-hour and 24-hour mode settings

• Oscillation adjustment circuit for correcting temperature frequency deviation or offset deviation

• CMOS process

• Two types of p ackage, SOP14(10.1x7.4x3.1) or SON22(6.1x5.0x1.3)

DD=3V

1

R2045S/D

PIN CONFIGURATION

32KOUT

R2045S (SOP14)

N.C.

SCLK SO

N.C. VPP

VDD N.C.

1 2

3 4 5

6 7

TOP VIEW

BLOCK DIAGRAM

14 13

12 11 10

N.C.

SI VSS INTR

9

N.C. CE

8

R2045D (SON22)

CE

1

VDD

2

N.C. N.C.

3

VPP

SO

VSS

INTR

N.C.

4 5 6 7

SI

8 9

10 11

32KOUT

SCLK

TOP VIEW

22 21 20 19 18 17 16 15 14

N.C. N.C.

N.C. N.C. N.C. N.C. N.C. N.C.

32KOUT

INTR

32kHz

OUTPUT

CONTROL

OSC

DETECT

DIVIDER CORREC

-TION

INTERRUPT CONTROL

DIV

COMPARATOR_W

COMPARATOR_D

(SEC,MIN,HOUR,WEEK,DAY,MONTH,YEAR)

ADDRESS DECODER

TIME COUNTER

SHIFT REGISTER

ALARM_W REGISTER

(MIN,HOUR, WEEK)

ALARM_D REGISTER

(MIN,HOUR)

ADDRESS

REGISTER

I/O

CONTROL

VOLTAGE

DETECT

TEST

CIRCUIT

VDD

VPP

VSS

SCLK SI

SO

CE

2

PIN DESCRIPTION

Symbol Item Description

CE Chip enable

Input

SCLK Serial Clock

Input

SI Serial Input The SI pin is used to input data intended for writing in synchronization with

SO Serial

Output

INTR

32KOUT 32kHz Clock

VDD Positive

VSS Negative

VPP Test input This pin is power pin for testing in the factory. Please don’t connect to any N.C. No

Interrupt Output

Output

Power Supply Input

Connection

The CE pin is used for interfacing with the CPU. Should be held high to allow access to the CPU. Incorporates a pull-down resistor. Should be held low or open when the CPU is powered off. Allows a maximum input voltage of 5.5v regardless of supply voltage. The SCLK pin is used to input clock pulses synchronizing the input and output of data to and from the SI and SO pins. Allows a maximum input voltage of 5.5v regardless of supply voltage.

the SCLK pin. CMOS input. Allows a maximum input voltage of 5.5v regardless of supply voltage. The SO pin is used to output data intended for reading in synchronization with the SCLK pin. CMOS output.

INTR

The interrupt (Alarm_D) and output periodic interrupt signals to the CPU sign als. Disabled at power-on from 0V. N-channel open drain output. Allows a maximum pull-up voltage of 5.5v regardless of supply voltage. The 32KOUT pin is used to output 32.768-kHz clock pulses. And controlled by resister setting. When VDD power-on from 0v, this output is enabled. The pin is N-channel open drain output. Allows a maximum pull-up voltage of 5.5v regardless of supply voltage. The VDD pin is connected to the power supply.

The VSS pin is grounded.

other pins. These pins are not connected to internal IC chip. In R2045D (SON22), N.C. pins from 14 pin to 22 pin are connected together internally. Never connect these pins to any lines, or connect to VDD or VSS. And never connect different voltage level lines each other.

pin is used to output alarm interrupt (Alarm_W) and alarm

R2045S/D

3

R2045S/D

ABSOLUTE MAXIMUM RATINGS

(VSS=0V)

Symbol Item Pin Name and Condition Description Unit

VDD Supply Voltage VDD -0.3 to +6.5 V

Input Voltage 1 CE, SCLK, SI -0.3 to +6.5 VI Input Voltage 2 VPP -0.3 to V Output Voltage 1 SO -0.3 to VDD+0.3 VO Output Voltage 2

PD Power Dissipation Topt Operating

Temperature

Tstg Storage Temperature -55 to +125

INTR

, 32KOUT

Topt=25°C

-40 to +85

-0.3 to +6.5 300 mW

DD+0.3

V V

°C °C

RECOMMENDED OPERATING CONDITION

(VSS=0V, Topt=-40 to +85°C)

Symbol Item Pin Name and Condition Min. Typ. Max. Unit

VACCESS Supply Voltage VDD power supply voltage

for interfacing with CPU

VCLK Time Keeping Voltage 1.15 5.5 V VPUP Pull-up Voltage

INTR

1.7 5.5 V

5.5 V

FREQUENCY CHARACTERISTICS

(VSS=0V)

Symbol Item Condition Min. Typ. Max. Unit

Δf/f0 Fv Frequency

Top Frequency

tsta Oscillation fa Aging

Frequency Deviation

Voltage Characteristics

Temperature Characteristics

Start-up Time

Topt=25°C, VDD=3V Topt=25°C,

DD=2.0V to 5.5V

V

Topt=-20°C to +70°C 25°C as standard

Topt=25°C, V Topt=25°C, V

First year

DD=2V DD=3V,

-5 0 +5 ppm

-1 +1 ppm

-120 +10 ppm

+1 sec

-5 +5 ppm

4

R2045S/D

DC ELECTRICAL CHARACTERISTICS

Unless otherwise specified: VSS=0V,VDD=3V,Topt=-40 to +85°C

Symbol Item Pin Name Condition Min. Typ. Max. Unit

VIH “H” Input Voltage 0.8x

CE,

DD=1.7 to 5.5V

V

SCLK,

VIL “L” Input Voltage IOH “H” Output

SI SO VOH=VDD-0.5V -0.5 mA

Current IOL1 IOL2

“L” Output Current

INTR

SO,

OL=0.4V

V

32KOUT

IIL Input Leakage

Current RDNCE Pull-down

SCLK, SI VI=5.5V or VSS

DD=5.5V

V

CE 40 120 400

Resistance IOZ1 SO VO=5.5V or VSS

IOZ2

IDD1

Output Off-state

Leakage Current

Time Keeping

Current

INTR

,

32KOUT VDD

VDD=5.5V VO=5.5V

VDD=3V, CE, SCLK, SI, SO,

INTR

, 32KOUT

SS

=V 32KOUT disabled

IDD2

VDD

VDD=5V, CE, SCLK, SI, SO,

INTR

, 32KOUT

SS

=V 32KOUT disabled

IDD3

VDD VDD=3V,

CE, SCLK, SI, SO,

INTR

, 32KOUT

SS

=V 32KOUT enabled

V

DETH

DETL

Supply Voltage

Monitoring Voltage

(“H”)

Supply Voltage

Monitoring Voltage

(“L”)

VDD

Topt=-30 to +70°C

DD

V

-0.3 0.2x

2.0

0.5

-1.0 1.0

0.65 2.00

1.90

1.15

5.5

DD

V

0.48 1.20

0.60 1.80

2.10 2.30

1.30 1.45

V

mA

μA kΩ

μA

V

5

R2045S/D

K

AC ELECTRICAL CHARACTERISTICS

Unless otherwise specified: VSS=0V,Topt=-40 TO +85°C Input / Output condition: V

Symbol Item Condi-

t

CE Set-up Time 400 ns

CES

t

CE Hold Time 400 ns

CEH

tCR CE Recovery Time 62 f

SCLK Clock Frequency 1.0 MHz

SCLK

t

SCLK Clock High Time 400 ns

CKH

t

SCLK Clock Low Time 400 ns

CKL

t

SCLK Set-up Time 200 ns

CKS

tRD Data Output Delay Time 300 ns tRZ Data Output Floating Time 300 ns t

Data Output Delay Time

CEZ

After Falling of CE tDS Input Data Set-up Time 200 ns tDH Input Data Hold Time 200 ns

IH=0.8xVDD,VIL=0.2xVDD,VOH=0.8xVDD,VOL=0.2xVDD,CL=50pF

V

DD≥1.7V

tions

Min. Typ. Max.

300 ns

t

CKH

t

CKL

Unit

μs

CE

t

CKS

SCL

SI

SO

*) For reading/writing timing, see “P. condition”.

t

CES

t

CEH

t

CEZ

tCR

t

DS

t

DH

tRD

t

RD

t

RZ

26 •Considerations in Reading and W riting Time Data under special

6

#

#7 #1 #

A

PACKAGE DIMENSIONS

• R2045S (SOP14)

1.24typ.

10.1±0.2

0.1

±

6.1

1.27±0.1

0.2

8

5.0±0.2

7.4±0.2

0.1

±

3.2

3.1typ.

-0.05

+0.1

0.1

14

+0.1

0.35

-0.05

• R2045D (SON22)

#22 #14

0°-10

0.15

°

+0.1

-0.05

0.65

0.25

±

0.6

R2045S/D

#22 #14

’

0.1

±

0.3

5.0

0.05

B

0.43

’

0.2

0.1

±

B

0.3

B

0.43

#1 #11

0.3

0.2

0.1

0.2

±

4.7

0.1

0.2

±

0.5

0.1

±

#1 #11

0.55typ.

1.3

+0.1/-0.05

0.125

0.1

7

R2045S/D

GENERAL DESCRIPTION

• Interface with CPU

The R2045S/D is connected to the CPU by four signal lines CE (Chip Enable), S CLK (Serial Clock), SI (Serial Input), and SO (Serial Output), through which it reads and writes data from and to the CPU. The CPU can be accessed when the CE pin is held high. Access clock pulses have a maximum frequency of 1 MHz allowing high-speed data transfer to the CPU.

• Clock and Calendar Function

The R2045S/D reads and writes time data from and to the CPU in units ranging from seconds to the last two digits of the calendar year. The calendar year will automatically be identified as a leap year when its last two digits are a multiple of 4. Consequently , leap years u p to the year 2099 can automatically be identified as such.

• Alarm Function

The R2045S/D incorporates the alarm interrupt circuit configured to generate interrupt signals to the CPU at preset times. The alarm interrupt circuit allows two types of alarm settings specified by the Alarm_W registers and the Alarm_D registers. The Alarm_W registers allow week, hour, and minute alarm settings including combinations of multiple day-of-week settings such as "Monday, Wednesday, and Friday" and "Saturday and Sunday". The Alarm_D registers allow hour and minute alarm settings. The Alarm_W outputs from pin, and the Alarm_D output s also from a polling function.

INTR

pin. Each alarm function can be checked from the CPU by using

High-precision Oscillation Adjustment Function

INTR

To correct deviations in the oscillation frequency of the crystal oscillator, the oscillation adjustment circuit is configured to allow correction of a time count gain or loss (up to ±1.5 ppm at 25°C) from the CPU within a maximum range of approximately + 189 ppm in increments of approximately 3 ppm. Such oscillation frequen cy adjustment in each system has the following advantages:

* Corrects seasonal frequency deviations through seasonal o scillation adjustment.

* Allows timekeeping with higher precision particularly with a temperature sensing function out of RTC, through oscillation adjustment in tune with temperature fluctuations.

• Oscillation Halt Sensing Flag, Power-on Reset Flag, and Supply Voltage Monitoring Function

The R2045S/D incorporates an oscillation halt sensing circuit equipped with internal registers configured to record any past oscillation halt.

Power-on reset flag is set to “1” When R2045S/D is powered on from 0V.

As such, the oscillation halt sensing flag and Power-on reset flag are useful for judging the validity of time data.

The R2045S/D also incorporates a supply voltage monitoring circuit equipped with internal registers configured to record any drop in supply voltage below a certain threshold value. Supply voltage monitoring threshold settings can be selected between 2.1 and 1.3 volts through internal register settings. The oscillation halt sensing circuit is configured to confirm the established invalidation of time data in contrast to the supply voltage monitoring circuit intended to confirm the potential invalidation of time data. Further, the supply voltage monitoring circuit can be applied to battery supply voltage monitoring.

8

R2045S/D

• Periodic Interrupt Function

The R2045S/D incorporates the periodic interrupt circuit configured to generate periodic interrupt signals aside from interrupt signals generated by the periodic interrupt circuit for output from the interrupt signals have five selectable frequency settings of 2 Hz (once per 0.5 seconds), 1 Hz (once per 1 second), 1/60 Hz (once per 1 minute), 1/3600 Hz (once per 1 hour), and monthly (the first day of every month). Further, periodic interrupt signals also have two selectable waveforms, a normal pulse form (with a frequency of 2 Hz or 1 Hz) and special form adapted to interruption from the CPU in the level mode (with second, minute, hour, and month interrupts). The condition of periodic interrupt signals can be monitored by using a polling function.

INTR

pin. Periodic

• 32kHz Clock Output

The R2045S/D incorporates a 32-kHz clock circuit configured to generate clock pulses with the oscillation frequency of a 32.768kHz crystal oscillator for output from the 32KOUT pin. The 32-kHz clock output can be disabled by certain register settings but cannot be disabled without manipulation of any two registers with different addresses to prevent disabling in such event s as the runaway of the CPU.

9

R2045S/D

A

Address Mapping

Address Register

Name

A3A2A1A0 D7 D6 D5 D4 D3 D2 D1 D0

0 0 0 0 0 Second

Counter

1 0 0 0 1 Minute

Counter

2 0 0 1 0 Hour Counter - - H20

3 0 0 1 1 Day-of-week

Counter

4 0 1 0 0 Day-of-month

Counter

5 0 1 0 1 Month

Counter and

Century Bit 6 0 1 1 0 Year Counter Y80 Y40 Y20 Y10 Y8 Y4 Y2 Y1 7 0 1 1 1 Oscillation

Adjustment

Register *3) 8 1 0 0 0 Alarm_W

(Minute

Register) 9 1 0 0 1 Alarm_W

(Hour

Register) A 1 0 1 0 Alarm_W

(Day-of-week

Register) B 1 0 1 1 Alarm_D

(Minute

Register) C 1 1 0 0 Alarm_D

(Hour

Register) D 1 1 0 1 - - - - - - - E 1 1 1 0 Control

Register 1 *3) F 1 1 1 1 Control

Register 2 *3)

Notes: *1) All the data listed above accept both reading and writing. *2) The data marked with "-" is invalid for writing and reset to 0 for reading. *3) When the PON bit is set to 1 in Control Register 2, all the bits are reset to 0 in Oscillation Adjustment Register, Control Register 1 and Control Register 2 excluding the *4) The (0) bit should be set to 0.

XST

*5) *6) PON is power-on reset flag.

is oscillation halt sensing bit.

*2)

- M40 M20 M10 M8 M4 M2 M1

- - - - - W4 W2 W1

- - D20 D10 D8 D4 D2 D1

19

/20

(0) *4)

- WM40 WM20 WM10 WM8 WM4 WM2 WM1

- - WH20

- WW6 WW5 WW4 WW3 WW2 WW1 WW0

- DM40 DM20 DM10 DM8 DM4 DM2 DM1

- - DH20

WALE DALE VDSL VDET

S40 S20 S10 S8 S4 S2 S1

P/

- - MO10 MO8 MO4 MO2 MO1

F6 F5 F4 F3 F2 F1 F0

12

/24

XST

WP/

DP/

D a t a

H10 H8 H4 H2 H1

WH10 WH8 WH4 WH2 WH1

DH10 DH8 DH4 DH2 DH1

CLEN2

PON *5)

TEST CT2 CT1 CT0

CLEN1

XST

CTFG WAFG DAFG

and PON bits.

10

R2045S/D

Register Settings

• Control Register 1 (ADDRESS Eh)

D7 D6 D5 D4 D3 D2 D1 D0

WALE DALE WALE DALE

0 0 0 0 0 0 0 0 Default Settings *)

*) Default settings: Default value means read / written values when the PON bit is set to “1” due to VDD

power-on from 0 volts.

12 12

/24 /24

CLEN2 CLEN2

(1) WALE, DALE Alarm_W Enable Bit, Alarm_D Enable Bit

WALE,DALE Description

0 Disabling the alarm interrupt circuit (under the control of the settings

of the Alarm_W registers and the Alarm_D registers).

1 Enabling the alarm interrupt circuit (under the control of the settings

of the Alarm_W registers and the Alarm_D registers)

12

(2)

(3)

/24

12

/24

0 Selecting the 12-hour mode with a.m. and p.m. indications. (Default) 1 Selecting the 24-hour mode

Setting the

24-hour mode 12-hour mode 24-hour mode 12-hour mode

00 12 (AM12) 12 32 (PM12) 01 01 (AM 1) 13 21 (PM 1) 02 02 (AM 2) 14 22 (PM 2) 03 03 (AM 3) 15 23 (PM 3) 04 04 (AM 4) 16 24 (PM 4) 05 05 (AM 5) 17 25 (PM 5) 06 06 (AM 6) 18 26 (PM 6) 07 07 (AM 7) 19 27 (PM 7) 08 08 (AM 8) 20 28 (PM 8) 09 09 (AM 9) 21 29 (PM 9) 10 10 (AM10) 22 30 (PM10) 11 11 (AM11) 23 31 (PM11)

Setting the

CLEN2

0 Enabling the 32-kHz clock output (Default) 1 Disabling the 32-kHz clock output

Setting the

pulses with the oscillation frequency of the 32.768-kHz crystal oscillator for output from the 32KOUT pin.

Conversely, setting both the

12

/24 bit to 0 and 1 specifies the 12-hour mode and the 24-hour mode, respectively.

12

/24 bit should precede writing time data

32-kHz Clock Output Bit2

CLEN2

bits or the

12

/24-hour Mode Selection Bit

CLEN1

bit (D3 in the control register 2) to 0 specifies generating clock

and the

TEST CT2 CT1 CT0 (For Writing) TEST CT2 CT1 CT0 (For Reading)

Description

CLEN2

bit to 1 specifies disabling (“H”) such output.

(Default)

11

R2045S/D

A

(4) TEST Test Bit

TEST Description

0 Normal operation mode. (Default) 1 Test mode.

The TEST bit is used only for testing in the factory and should normally be set to 0.

(5) CT2,CT1, and CT0 Periodic Interrupt Selection Bits

Description CT2 CT1 CT0

Wave form

mode

0 0 0 - OFF(H) (Default) 0 0 1 - Fixed at “L” 0 1 0 Pulse Mode

*1)

0 1 1 Pulse Mode

*1)

1 0 0 Level Mode

*2)

1 0 1 Level Mode

*2)

1 1 0 Level Mode

*2)

1 1 1 Level Mode

*2)

* 1) Pulse Mode: 2-Hz and 1-Hz clock pulses are output in synchronization with the increment of the second counter as illustrated in the timing chart below.

Interrupt Cycle and Falling Timing

2Hz(Duty50%) 1Hz(Duty50%) Once per 1 second (Synchronized with

second counter increment) Once per 1 minute (at 00 seconds of every minute) Once per hour (at 00 minutes and 00 seconds of every hour) Once per month (at 00 hours, 00 minutes, and 00 seconds of first day of every month)

12

In the pulse mode, the increment of the second counter is delayed by approximately 92 μs from the falling edge of clock pulses. Consequently, time readings immediately after the falling edge of clock pulses may appear to lag behind the time counts of the real-time clocks by approximately 1 second. Rewriting the second counter will reset the other time counters of less than 1 second, driving the

* 2) Level Mode: Periodic interrupt signals are output with selectable interrupt cycle settings of 1 second, 1 minute, 1 hour, and 1 month. The increment of the second counter is synchronized with the falling edge of periodic interrupt signals. For example, periodic interrupt signals with an interrupt cycle setting of 1 second are output in synchronization with the increment of the second counter as illustrated in the timing chart below.

CTFG Bit

IN T R

pprox. 92μs

(Increment of second counter)

INTR

pin low.

Rewriting of the second counter

R2045S/D

*1), *2) When the oscillation adjustment circuit is used, the interrupt cycle will fluctuate once per 60sec. as follows: Pulse Mode: The “L” period of output pulses will increment or decrement by a maximum of ±3.784 ms. For example, 1-Hz clock pulses will have a duty cycle of 50 ±0.3784%. Level Mode: A periodic interrupt cycle of 1 second will increment or decrement by a maximum of ±3.784 ms.

CTFG Bit

IN T R

(Increment of second counter)

Setting CTFG bit to 0

(Increment of second counter)

Setting CTFG bit to 0

(Increment of second counter)

• Control Register 2 (Address Fh)

D7 D6 D5 D4 D3 D2 D1 D0

VDSL VDET VDSL VDET

0 0 *) Default settings: Default value means read / written values when the PON bit is set to “1” due to VDD power-on from 0 volts.

XST XST

Indefinite

PON PON

1 0 0 0 0 Default Settings *)

CLEN1 CLEN1

(1) VDSL VDD Supply Voltage Monitoring Threshold Selection Bit

VDSL Description

0 Selecting the VDD supply voltage monitoring threshold setting of 2.1v. (Default) 1 Selecting the VDD supply voltage monitoring threshold setting of 1.3v.

The VDSL bit is intended to select the VDD supply voltage monitoring threshold settings.

(2) VDET Supply Voltage Monitoring Result Indication Bit

VDET Description

0 Indicating supply voltage above the supply voltage monitoring

threshold settings.

1 Indicating supply voltage below the supply voltage monitoring

threshold settings. Once the VDET bit is set to 1, the supply voltage monitoring circuit will be disabled while the VDET bit will hold the setting of 1. The VDET bit accepts only the writing of 0, which restarts the supply voltage monitoring circuit. Conversely, setting the VDET bit to 1 causes no event.

XST

(3)

Oscillation Halt Sensing Monitor Bit

XST

0 Sensing a halt of oscillation 1 Sensing a normal condition of oscillation

CTFG WAF

G

CTFG WAF

G

Description

DAFG (For Writing) DAFG (For Reading)

(Default)

13

R2045S/D

XST

The halt sensing. The

accepts the reading and writing of 0 and 1. The

XST

bit will hold 0 even after the restart of oscillation.

(4) PON Power-on-reset Flag Bit

PON Description

0 Normal condition 1 Detecting VDD power-on -reset (Default)

The PON bit is for sensing power-on reset condition.

* The PON bit will be set to 1 when VDD power-on from 0 volts. The PON bit will hold the setting of 1 even after power-on. * When the PON bit is set to 1, all bits will be reset to 0, in the Oscillation Adjustment Register, Control Register 1, and Control Register 2, except 32KOUT starts outputting. * The PON bit accepts only the writing of 0. Conversely, setting the PON bit to 1 causes no event.

CLEN1

(5)

Setting the pulses with the oscillation frequency of the 32.768-kHz crystal oscillator for output from the 32KOUT pin. Conversely, setting both the

32-kHz Clock Output Bit 1

CLEN1

0 1

CLEN1

Enabling the 32-kHz clock output Disabling the 32-kHz clock output

bit or the

CLEN2

CLEN1

XST

and PON. As a result,

Description

bit (D4 in the control register 1) to 0 specifies generating clock

and the

CLEN2

(6) CTFG Periodic Interrupt Flag Bit

CTFG Description

0 Periodic interrupt output = “H” (Default)

1 Periodic interrupt output = “L” The CTFG bit is set to 1 when the periodic interrupt signals are output from the CTFG bit accepts only the writing of 0 in the level mode, which disables (“H”) the enabled (“L”) again in the next interrupt cycle. Conversely, setting the CTFG bit to 1 causes no event.

(7) WAFG,DAFG Alarm_W Flag Bit and Alarm_D Flag Bit

WAFG,DAFG Description

0 Indicating a mismatch between current time and preset alarm time (Default)

1 Indicating a match between current time and preset alarm time The WAFG and DAFG bits are valid only when the WALE and DALE have the setting of 1, which is caused approximately 61μs after any match between current time and preset alarm time specified by the Alarm_W registers and the Alarm_D registers. The WAFG (DAFG) bit accepts only the writing of 0. outputs off (“H”) when this bit is set to 0. And Conversely, setting the WAFG and DAFG bits to 1 causes no event. The WAFG and DAFG bits will have the reading of 0 when the alarm interrupt circuit is disabled with the WALE and DALE bits set to 0. The settings of the WAFG (DAFG) bit is synchronized with the output of the timing chart below.

INTR

pin outputs “L” again at the next preset alarm time.

XST

bit will be set to 0 when the oscillation

INTR

pin stops outputting, and

(Default)

bit to 1 specifies disabling (“H”) such output.

INTR

pin (“L”). The

INTR

pin until it is

INTR

pin as shown in the

14

R2045S/D

A

pprox. 61μs

WAFG(DAFG) Bit

INTR Pin

Writing of 0 to

WAFG(DAFG) bit (Match between current time and preset alarm time)

(Match between current time and preset alarm time)

Writing of 0 to

WAFG(DAFG) bit (Match between current time and preset alarm time)

• Time Counter (Address 0-2h)

Second Counter (Address 0h)

D7 D6 D5 D4 D3 D2 D1 D0

- S40 S20 S10 S8 S4 S2 S1 (For Writing) 0 S40 S20 S10 S8 S4 S2 S1 (For Reading) 0 Indefi

nite

Minute Counter (Address 1h)

D7 D6 D5 D4 D3 D2 D1 D0

- M40 M20 M10 M8 M4 M2 M1 (For Writing) 0 M40 M20 M10 M8 M4 M2 M1 (For Reading) 0 Indefi

nite

Hour Counter (Address 2h)

D7 D6 D5 D4 D3 D2 D1 D0

- -

0 0

0 0 Indefi

*) Default settings: Default value means read / written values when the PON bit is set to “1” due to VDD power-on from 0 volts.

* Time digit display (BCD format) as follows: The second digits range from 00 to 59 and are carried to the minute digit in transition from 59 to 00. The minute digits range from 00 to 59 and are carried to the hour digits in transition from 59 to 00. The hour digits range as shown in "P

Mode Selection Bit" and are carried to the day-of-month and day-of-week digits in tran sition from PM11 to AM12 or from 23 to 00.

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P/ or H20

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H10 H8 H4 H2 H1 (For Writing)

H10 H8 H4 H2 H1 (For Reading)

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11 •Control Register 1 (ADDRESS Eh) (2)

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Default Settings *)

12

/24: 12-24-hour

15

R2045S/D

* Any writing to the second counter resets divider units of less than 1 second. * Any carry from lower digits with the writing of non-existent time may cause the time counters to

malfunction. Therefore, such incorrect writing should be replaced with the writing of existent time data.

• Day-of-week Counter (Address 3h)

D7 D6 D5 D4 D3 D2 D1 D0

- - - - - W4 W2 W1 (For Writing) 0 0 0 0 0 W4 W2 W1 (For Reading) 0 0 0 0 0 Indefi

nite *) Default settings: Default value means read / written values when the PON bit is set to “1” due to VDD power-on from 0 volts.

* The day-of-week counter is incremented by 1 when the day-of-week digits are carried to the day-of-month

digits.

* Day-of-week display (incremented in septimal notation):

(W4, W2, W1) = (0, 0, 0) → (0, 0, 1)→…→(1, 1, 0) → (0, 0, 0) * Correspondences between days of the week and the day-of-week digits are user-definable (e.g. Sunday = 0, 0, 0) * The writing of (1, 1, 1) to (W4, W2, W1) is prohibited except when days of the week are unused.

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Default Settings *)

• Calendar Counter (Address 4-6h)

Day-of-month Counter (Address 4h)

D7 D6 D5 D4 D3 D2 D1 D0

- - D20 D10 D8 D4 D2 D1 (For Writing) 0 0 D20 D10 D8 D4 D2 D1 (For Reading) 0 0 Indefi

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Month Counter + Century Bit (Address 5h)

D7 D6 D5 D4 D3 D2 D1 D0

19 19

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/20 /20

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- - MO10 MO8 MO4 MO2 MO1 (For Writing) 0 0 MO10 MO8 MO4 MO2 MO1 (For Reading) 0 0 Indefi

Year Counter (Address 6h)

D7 D6 D5 D4 D3 D2 D1 D0

Y80 Y40 Y20 Y10 Y8 Y4 Y2 Y1 (For Writing) Y80 Y40 Y20 Y10 Y8 Y4 Y2 Y1 (For Reading)

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nite *) Default settings: Default value means read / written values when the PON bit is set to “1” due to VDD power-on from 0 volts.

* The calendar counters are configured to display the calendar digits in BCD format by using the automatic

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Default Settings *)

16