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RX

 − 

8801 SA / JE

 

 

 

Page - 1 

ETM26E-03

 

 

I

2

C-Bus Interface Real-time Clock Module 

 

 

RX

 − 

8801

 SA / JE

 

 

 

  Features built-in 32.768 kHz DTCXO, High Stability. 

 

 

Supports I

2

C-Bus's high speed mode (400 kHz)

 

 

  Alarm interrupt function for day, date, hour, and minute settings 

  Fixed-cycle timer interrupt function   

  Time update interrupt function   

(Seconds, minutes)

  32.768 kHz output with OE function   

(FOE and FOUT pins)

  Auto correction of leap years   

(from 2000 to 2099)

  Wide interface voltage range: 2.2 V to 5.5 V 

  Wide time-keeping voltage range:1.6 V to 5.5 V 

  Low current consumption: 0.8

μ

A / 3 V (Typ.) 

 

The I

2

C-BUS is a trademark of NXP Semiconductors. 

 
 

1. Overview 

 

This module is an I

2

C bus interface-compliant real-time clock which includes a 32.768 kHz DTCXO.   

In addition to providing a calendar (year, month, date, day, hour, minute, second) function and a clock counter 
function, this module provides an abundance of other functions including an alarm function, fixed-cycle timer 
function,

 

time update interrupt function,

 

and 32.768 kHz output function.   

The devices in this module are fabricated via a C-MOS process for low current consumption, which enables 
long-term battery back-up.   
All of these many functions are implemented in SOP-14 pin and VSOJ-20 pin package.   

 
 

2. Block Diagram 

 

 

32kHz 

DTCXO 

32.768 kHz

 

      CLOCK 

and 

CALENDAR 

   

TIMER 

REGISTER 

   

ALARM 

REGISTER 

   

FOUT 

CONTROLLER 

 
CONTROL 

REGISTER 

 

and 

 

SYSTEM 

CONTROLLER 

 

  DIVIDER 

 

INTERRUPT 

CONTROLLER 

 
 
 

I2C-BUS 

INTERFACE 

CIRCUIT 

FOUT 

FOE 

/ INT 

SCL 

SDA 

 

 

Содержание RX-8801JE

Страница 1: ...ETM26E 03 Application Manual Real Time Clock Module RX 8801SA JE ...

Страница 2: ...for other military purposes You are also requested that you would not make the products available to any third party who may use the products for such prohibited purposes These products are intended for general use in electronic equipment When using them in specific applications that require extremely high reliability such as applications stated below it is required to obtain the permission from E...

Страница 3: ...ixed cycle timer interrupt function 14 8 3 2 Related registers for function of time update interrupts 15 8 3 3 Fixed cycle timer interrupt interval example 16 8 3 4 Fixed cycle timer start timing 16 8 4 Time Update Interrupt Function 17 8 4 1 Time update interrupt function diagram 17 8 4 2 Related registers for time update interrupt functions 18 8 5 Alarm Interrupt Function 19 8 4 1 Diagram of ala...

Страница 4: ...rview This module is an I 2 C bus interface compliant real time clock which includes a 32 768 kHz DTCXO In addition to providing a calendar year month date day hour minute second function and a clock counter function this module provides an abundance of other functions including an alarm function fixed cycle timer function time update interrupt function and 32 768 kHz output function The devices i...

Страница 5: ...s the C MOS output pin with output control provided via the FOE pin When FOE H high level this pin outputs a 32 768 kHz signal When output is stopped the FOUT pin Hi Z high impedance FOE Input This is an input pin used to control the output mode of the FOUT pin When this pin s level is high the FOUT pin is in output mode When it is low output via the FOUT pin is stopped INT Output This pins is use...

Страница 6: ...sation voltage VTEM Temperature compensation voltage 2 2 3 0 5 5 V Clock supply voltage VCLK 1 6 3 0 5 5 V Operating temperature TOPR No condensation 40 25 85 C 6 Frequency Characteristics GND 0 V Item Symbol Condition Rating Unit U A Ta 0 to 40 C VDD 3 0 V Ta 40 to 85 C VDD 3 0 V 1 9 1 3 4 2 Frequency stability Δ f f U B Ta 0 to 50 C VDD 3 0 V Ta 40 to 85 C VDD 3 0 V 3 8 3 5 0 4 10 6 Frequency vo...

Страница 7: ...DD 3 V 0 72 1 85 μA Current consumption 9 IDD9 VDD 5 V 430 900 Current consumption 10 IDD10 fSCL 0 Hz INT VDD FOE GND FOUT output OFF High Z Compensation ON peak VDD 3 V 180 350 μA FOE pin 0 8 VDD VDD 0 3 High level input voltage VIH SCL and SDA pins 0 7 VDD 5 5 V FOE pin GND 0 3 0 2 VDD Low level input voltage VIL SCL and SDA pins GND 0 3 0 3 VDD V VOH1 VDD 5 V IOH 1 mA 4 5 5 0 VOH2 VDD 3 V IOH 1...

Страница 8: ...CL H tHIGH 0 6 μs Rise time for SCL and SDA tr 0 3 μs Fall time for SCL and SDA tf 0 3 μs Allowable spike time on bus tSP 50 ns FOUT duty tW t 50 of VDD level 40 50 60 Timing chart tHD DAT tSU DAT tHD STA tLOW tHIGH 1 fSCL tr tf tSU STA SDA SCL START CONDITION S BIT 7 MSB A7 BIT 6 A6 ACK A Protocol tBUF tSU STO STOP CONDITION P START CONDITION S P A tHD STA tSU STA S BIT 0 LSB R W S tSP Caution Wh...

Страница 9: ...T pin goes to low level to indicate that an event has occurred However when a fixed cycle timer interrupt event has been generated low level output from the INT pin occurs only when the value of the control register s UIE bit is 1 This INT status is automatically cleared INT status changes from low level to Hi Z 7 8 ms a fixed value after the interrupt occurs 4 Alarm interrupt function The alarm i...

Страница 10: ...ET 1 2 3 F Control Register CSEL1 CSEL0 UIE TIE AIE RESET 3 Note When after the initial power up or when the result of read out the VLF bit is 1 initialize all registers before using the module Be sure to avoid entering incorrect date and time data as clock operations are not guaranteed when the data or time data is incorrect 1 During the initial power up the TEST bit is reset to 0 and the VLF bit...

Страница 11: ...nt occurs an interrupt signal is not generated or is canceled INT status changes from low to Hi Z Write Read 1 When a time update interrupt event occurs an interrupt signal is generated INT status changes from Hi Z to low When a time update interrupt event occurs low level output from the INT pin occurs only when the value of the control register s UIE bit is 1 This INT status is automatically cle...

Страница 12: ...ia the INT pin use software to monitor the value of the UF TF and AF interrupt flags 4 RESET bit It also resets the RTC module s internal counter value when the value is less than one second Writing a 1 to this bit stops the counter operation and resets the RTC module s internal counter value when the value is less than one second If a STOP condition or repeated START condition I2 C is received wh...

Страница 13: ... has occurred Once this flag bit s value is 1 its value is retained until a 0 is written to it For details see 8 5 Alarm Interrupt Function 4 VLF Voltage Low Flag bit This flag bit indicates the retained status of clock operations or internal data Its value changes from 0 to 1 when data loss occurs such as due to a supply voltage drop Once this flag bit s value is 1 its value is retained until a 0...

Страница 14: ...ting a 1 to this bit specifies DAY as the comparison object for the alarm interrupt function Writing a 0 to this bit specifies WEEK as the comparison object for the alarm interrupt function 3 USEL Update Interrupt Select bit This bit is used to specify either second update or minute update as the update generation timing of the time update interrupt function USEL Data update interrupts Auto reset ...

Страница 15: ...20 10 8 4 2 1 This minute counter counts from 00 to 01 02 and up to 59 minutes after which it starts again from 00 minutes 3 Hour counter Address Function bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 2 HOUR 20 10 8 4 2 1 This hour counter counts from 00 hours to 01 02 and up to 23 hours after which it starts again from 00 hours 8 2 7 Day counter Reg 3 Address Function bit 7 bit 6 bit 5 bit 4 bi...

Страница 16: ...uary and up to 12 December then starts again at 01 January 3 Year counter Address Function bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 6 Years Y80 Y40 Y20 Y10 Y8 Y4 Y2 Y1 The year counter counts from 00 01 02 and up to 99 then starts again at 00 Any year that is a multiple of four 04 08 12 88 92 96 etc is handled as a leap year 8 2 9 Alarm registers Reg 8 A Address Function bit 7 bit 6 bit 5 b...

Страница 17: ...xed cycle timer stops 1 1 2 001 h 000 h 3 4 5 1 6 7 7 7 8 9 1 When a 1 is written to the TE bit the fixed cycle timer countdown starts from the preset value 2 A fixed cycle timer interrupt event starts a countdown based on the countdown period source clock When the count value changes from 001h to 000h an interrupt event occurs After the interrupt event that occurs when the count value changes fro...

Страница 18: ... to the source clock setting 2 When the source clock has been set to second update or minute update the timing of both countdown and interrupts is coordinated with the clock update timing 2 Fixed cycle Timer Control register Reg B to C This register is used to set the default preset value for the counter Any count value from 1 001 h to 4095 FFFh can be set The counter counts down based on the sour...

Страница 19: ... 3 3 Fixed cycle timer interrupt interval example Source clock Timer Counter setting 4096 Hz TSEL1 0 0 0 64 Hz TSEL1 0 0 1 Second update TSEL1 0 1 0 Minute update TSEL1 0 1 1 0 1 244 14 μs 15 625 ms 1 s 1 min 2 488 28 μs 31 25 ms 2 s 2 min 41 10 010 ms 640 63 ms 41 s 41 min 205 50 049 ms 3 203 s 205 s 205 min 410 100 10 ms 6 406 s 410 s 410 min 2048 500 00 ms 32 000 s 2048 s 2048 min 4095 0 9998 s...

Страница 20: ...eared to zero Operation in RTC i i Write operation 1 2 3 4 1 5 6 7 1 A time update interrupt event occurs when the internal clock s value matches either the second update time or the minute update time The USEL bit s specification determines whether it is the second update time or the minute update time that must be matched 2 When a time update interrupt event occurs the UF bit value becomes 1 3 W...

Страница 21: ...0 to 1 when a time update interrupt event occurs When this flag bit 1 its value is retained until a 0 is written to it UF Data Description 0 The UF bit is cleared to zero to prepare for the next status detection Clearing this bit to zero does not enable the INT low output status to be cleared to Hi Z Write 1 This bit is invalid after a 1 has been written to it 0 Time update interrupt events are no...

Страница 22: ...ime is used as the setting the alarm will not occur until the counter counts up to the current date time i e an alarm will occur next time not immediately 2 When a time update interrupt event occurs the AF bit values becomes 1 3 When the AF bit 1 its value is retained until it is cleared to zero 4 If AIE 1 when an alarm interrupt occurs the INT pin output goes low When an alarm interrupt event occ...

Страница 23: ...used to specify either WEEK or DAY as the target for alarm interrupt events WADA Data Description 0 Sets WEEK as target of alarm function DAY setting is ignored Write Read 1 Sets DAY as target of alarm function WEEK setting is ignored 2 Alarm registers Reg 8 to A Address Function bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 8 MIN Alarm AE 40 20 10 8 4 2 1 9 HOUR Alarm AE 20 10 8 4 2 1 WEEK Alar...

Страница 24: ...he AIE bit value is 0 another interrupt event may change the INT status to low or may hold INT L Write Read 1 When an alarm interrupt event occurs an interrupt signal is generated INT status changes from Hi Z to low When an alarm interrupt event occurs low level output from the INT pin occurs only when the AIE bit value is 1 This value is retained not automatically cleared until the AF bit is clea...

Страница 25: ...its slave address matches the slave address in the received data In either case the data is transferred via the SCL line at a rate of one bit per clock pulse 8 6 2 System configuration All ports connected to the I2 C bus must be either open drain or open collector ports in order to enable AND connections to multiple devices SCL and SDA are both connected to the VDD line via a pull up resistance Co...

Страница 26: ... stopped at any time while in progress However this is only when this RTC module is in receiver mode data reception mode SDA released 3 When communicating with this RTC module the series of operations from transmitting the START condition to transmitting the STOP condition should occur within 0 95 seconds A RESTART condition may be sent between a START condition and STOP condition but even in such...

Страница 27: ...pulse corresponding to the 8th bit of data on the SCL line the transmitter releases the SDA line and the receiver sets the SDA line to low acknowledge level SCL from Master SDA from transmitter sending side ACK signal 1 2 8 9 SDA from receiver receiving side Release SDA Low active After transmitting the ACK signal if the Master remains the receiver for transfer of the next byte the SDA is released...

Страница 28: ...01 6 CPU transfers RESTART condition Sr in which case CPU does not transfer a STOP condition P 7 CPU transfers RX 8801 s slave address with the R W bit set to read mode 8 Check for ACK signal from RX 8801 from this point on the CPU is the receiver and the RX 8801 is the transmitter 9 Data from address specified at 4 above is output by the RX 8801 10 CPU transfers ACK signal to RX 8801 11 Repeat 9 ...

Страница 29: ...K 0 V VDET Item Symbol Condition Min Typ Max Unit Power supply detection voltage 1 VDET 2 2 V Power supply detection voltage 2 VLOW 1 6 V Power supply drop time t F 2 μs V Initial power up time t R1 10 ms V 1 6V VDD 3 6V 5 μs V Clock maintenance power up time t R2 1 6V VDD 3 6V 15 μs V ...

Страница 30: ...ode Note SDA SCL SLAVE ADRS 0110 010 Note It uses the secondary battery or a lithium battery When using the seconding battery the diode is not required When using the lithium battery the diode is required For detailed value on the resistance please consult a battery maker 8 9 When used as a clock source 32 kHz TCXO RX 8801 VDD T1 GND 0 1 μF FOUT INT SCL SDA FOE VDD 32 768kHz O E TEST T2 VDD ...

Страница 31: ...1 27 1 27 6 7 62 0 7 Unit mm 10 1 0 2 5 0 7 4 0 2 14 8 7 1 1 27 1 2 0 05 Min 3 2 0 1 0 35 The cylinder of the crystal oscillator can be seen in this area front but it has no affect on the performance of the device 9 1 2 Marking layout RX 8801 SA SOP 14pin Logo Type Production lot R 8801 E A123B Contents displayed indicate the general markings and display but are not the standards for the fonts siz...

Страница 32: ...nit mm 1 5 3 8 1 5 0 65 9 5 85 0 3 0 35 0 65 5 4 7 0 0 3 1 20 11 10 The cylinder of the liquid crystal oscillator can be seen in this area back and front but it has no affect on the performance of the device 9 2 2 Marking layout RX 8801 JE VSOJ 20pin Logo Type Production lot R 8801 E A123B Contents displayed indicate the general markings and display but are not the standards for the fonts sizes an...

Страница 33: ...nce If the temperature within the package exceeds 260 C the characteristics of the crystal oscillator will be degraded and it may be damaged The reflow conditions within our reflow profile is recommended Therefore always check the mounting temperature and time before mounting this device Also check again if the mounting conditions are later changed See Fig 2 profile for our evaluation of Soldering...

Страница 34: ... Beijing China 100005 Phone 86 10 8522 1199 Fax 86 10 8522 1120 http www epson com cn Shanghai Branch High Tech Building 900 Yishan Road Shanghai 200233 China Phone 86 21 5423 5577 Fax 86 21 5423 4677 Shenzhen Branch 12 F Dawning Mansion 12 Keji South Road Hi Tech Park Shenzhen China Phone 86 755 26993828 Fax 86 755 26993838 EPSON HONG KONG LTD 20 F Harbour Centre 25 Harbour Road Wanchai Hong kong...

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