R EM MICROELECTRONIC - MARIN SA EM3027 Real Time Clock with I2C or SPI, Crystal Temperature Compensation, Battery Switchover and Trickle Charger Description The EM3027 is an Ultra Low Power CMOS real-time clock IC with two serial interface modes: I2C or SPI. The interface mode is selected by the chip version (see §12). The basic clock is obtained from the 32.768 kHz crystal oscillator. A thermal compensation of the frequency is based on the temperature measurement and calculation of the correction value. The temperature can be measured internally or be input by an external application to the register. The chip provides clock and calendar information in BCD format with alarm possibility. The actual contents are latched at the beginning of a read transmission and afterwards data are read without clock counter data corruption. An integrated 16-bit timer can run in Zero-Stop or AutoReload mode. An interrupt request signal can be provided through INT/IRQ pin generated from alarm, timer, voltage detector and Self-Recovery system. An integrated trickle charger allows recharging backup supply VBack from the main supply voltage VCC through internal resistor(s). The internal device supply will switchover to VCC when VCC is higher than VBack and vice versa. The device operates over a wide 1.4 to 5.5V supply range and requires only 900 nA at 5V. It can detect internally two supply voltage levels. Applications Utility meters Battery operated and portable equipment Consumer electronics White/brown goods Pay phones Cash registers Personal computers Programmable controller systems Data loggers Features Fully operational from 2.1 to 5.5V Supply current typically 600 nA at 1.4V Thermal compensated crystal frequency Oscillator stability 0.5 ppm / Volt Counter for seconds, minutes, hours, day of week, date months, years in BCD format and alarm Leap year compensation 16-bits timer with 2 working modes Two low voltage detection levels VLow1, VLow2 Automatic supply switchover 2 Serial communication via I2C (I C-bus specification Rev. 03 compatible – see §10.2) or SPI (3-line SPIbus with separate combinable data input and output) Thermometer readable by the host Trickle charger to maintain battery charge Integrated oscillator capacitors Two EEPROM and 8 RAM data bytes for application Digital Self-Recovery system No busy states and no risk of corrupted data while accessing One hour periodical configuration registers refresh Support for standard UL1642 for Lithium batteries Standard temperature range: -40°C to +85°C Extended temperature range: -40°C to +125°C Packages: TSSOP8, TSSOP14, SO8. Block Diagram EM3027 Temperature Sensor X1 Oscillator X2 VCC VREG VBack SCL/SCK SDA/SO SI Power Management I2C or SPI CS CLKOUT INT or IRQ CLKOE Watch & Alarm - Seconds - Minutes - Hours - Days - Weekdays - Months - Years Timer Output Control EEPROM Copyright © 2009, EM Microelectronic-Marin SA 12/09 – rev D 1 www.emmicroelectronic.com R EM3027 Table of contents Table of contents..................................................................................................................................................................... 2 1 Packages / Pin Out Configuration .................................................................................................................................... 3 2 Absolute Maximum Ratings.............................................................................................................................................. 4 2.1 Handling Procedures................................................................................................................................................. 4 2.2 Operating Conditions ................................................................................................................................................ 4 2.3 Crystal characteristics ............................................................................................................................................... 4 2.4 EEPROM Characteristics .......................................................................................................................................... 4 3 Electrical Characteristics .................................................................................................................................................. 4 4 EM3027 Block Diagram and Application Schematic......................................................................................................... 6 4.1 Block Diagram........................................................................................................................................................... 6 4.2 Application Schematic ............................................................................................................................................... 6 4.3 Crystal Thermal Behaviour........................................................................................................................................ 7 4.4 Crystal Calibration..................................................................................................................................................... 8 5 Memory Mapping.............................................................................................................................................................. 9 6 Definitions of terms in the memory mapping .................................................................................................................. 10 7 Serial communication ..................................................................................................................................................... 12 7.1 How to perform data transmission through I2C ....................................................................................................... 12 7.2 How to perform data transmission through SPI....................................................................................................... 13 8 Functional Description.................................................................................................................................................... 15 8.1 Start after power-up ................................................................................................................................................ 15 8.2 Normal Mode function ............................................................................................................................................. 15 8.3 Watch and Alarm function ....................................................................................................................................... 15 8.4 Timer function ......................................................................................................................................................... 16 8.5 Temperature measurement..................................................................................................................................... 16 8.6 Frequency compensation ........................................................................................................................................ 16 8.7 EEPROM memory................................................................................................................................................... 17 8.8 RAM User Memory.................................................................................................................................................. 18 8.9 Status Register........................................................................................................................................................ 18 8.10 Interrupts ............................................................................................................................................................ 18 8.11 Self-Recovery System (SRS) ............................................................................................................................. 19 8.12 Register Map ...................................................................................................................................................... 19 8.13 Crystal Oscillator and Prescaler ......................................................................................................................... 19 9 Power Management ................................................................................................................................................ 20 9.1 Power Supplies, Switchover and Trickle Charger ................................................................................................... 20 9.2 Low Supply Detection ............................................................................................................................................. 21 10 AC Characteristics .................................................................................................................................................. 22 10.1 AC characteristics – I2C ..................................................................................................................................... 22 10.2 I2C Specification compliance ............................................................................................................................. 23 10.3 AC characteristics – SPI..................................................................................................................................... 24 11 Package Information ............................................................................................................................................... 26 11.1 TSSOP-08/14 ..................................................................................................................................................... 26 11.2 SO-8................................................................................................................................................................... 27 12 Ordering Information ............................................................................................................................................... 28 Copyright © 2009, EM Microelectronic-Marin SA 12/09 – rev D 2 www.emmicroelectronic.com R EM3027 1 Packages / Pin Out Configuration SO8-TSSOP8 Vcc X1 X2 VBack IRQ/CLKOUT EM3027 SCL Vss SDA I2C TSSOP14 X1 NC X2 CLKOE SI VCC VReg EM3027 VBack IRQ/CLKOUT CS INT SCK Vss SO SPI Pin 1 2 3 4 5 6 7 8 Table 1 Name X1 X2 VBack VSS SDA SCL IRQ/CLKOUT VCC Pin 1 2 3 Name X1 X2 SI 4 VReg 5 VBack INT 6 7 8 9 10 11 12 VSS SO SCK CS IRQ/CLKOUT VCC 13 CLKOE 14 NC Table 2 Copyright © 2009, EM Microelectronic-Marin SA 12/09 – rev D 3 Function 32.768 kHz crystal input 32.768 kHz crystal output Backup Supply Ground Supply Serial Data Serial Clock Interrupt Request/Clock output Positive Supply Function 32.768 kHz crystal input 32.768 kHz crystal output Serial Data input Regulated Voltage – Reserved for test purpose (This output must be left unconnected) Backup Supply Interrupt Request output (Open Drain active low) Ground Supply Serial Data output Serial Clock input Chip Select input Interrupt Request/Clock output Positive Supply Clock Output Enable CLKOE = ‘0’ CLKOUT is low CLKOE = ‘1’ CLKOUT is output Not Connected www.emmicroelectronic.com R EM3027 2 Operating Conditions Absolute Maximum Ratings Parameter Maximum voltage at VCC Minimum voltage at VCC Maximum voltage at any signal pin Minimum voltage at any signal pin Maximum storage temperature Minimum storage temperature Electrostatic discharge maximum to MIL-STD-883C method 3015.7 with ref. to VSS Table 3 Symbol VCCmax VCCmin Conditions VSS + 6.0V VSS – 0.3V Vmax VCC + 0.3V Vmin VSS – 0.3V TSTOmax +150°C TSTOmin -65°C VSmax 2000V Parameter Symbol 2.3 Symbol Frequency Load capacitance Series resistance Table 5 Max Unit +125 °C 5.5 V nF Min f CL RS 7 Typ Max Unit 32.768 kHz 8.2 12.5 pF 70 110 kΩ Crystal Reference : Micro Crystal CC5V-T1A web: www.microcrystal.com 2.4 EEPROM Characteristics Parameter Handling Procedures Symbol Read voltage Programming Voltage This device has built-in protection against high static voltages or electric fields; however, anti-static precautions must be taken as for any other CMOS component. Unless otherwise specified, proper operation can only occur when all terminal voltages are kept within the voltage range. Unused inputs must always be tied to a defined logic voltage level. EEPROM Programming Time Write/Erase Cycling Table 6 2.2 3 Typ Crystal characteristics Parameter Stresses above these listed maximum ratings may cause permanent damages to the device. Exposure beyond specified operating conditions may affect device reliability or cause malfunction. 2.1 Min TA Operating Temp. -40 Supply voltage VCC, 1.4 5.0 VBack (Note 1) Capacitor at VCC, CD 100 VBack Table 4 Note 1: Refer to paragraphs 9.1 and 9.2 Min Typ Max Unit VRead 1.4 V VProg 2.2 V 30 TProg 5000 ms cycles Electrical Characteristics Parameter Total supply current with Crystal Total supply current with Crystal Symbol ICC IBack Test Conditions All outputs open, Rs < 70 kΩ, VBack = 0V I2C: SDA, SCL at VCC, Clk/Int=’0’ SPI: All inputs at VSS VCC 1.4 3.3 5.0 All outputs open, Rs < 70 kΩ, VCC = 0V I2C: SDA, SCL at VBack, Clk/Int=’0’ SPI: All inputs at VSS VBack 1.4 3.3 0 5.0 Dynamic current I2C IDD SCL = 100kHz (See Note 1) SCL = 400kHz (See Note 1) SCL = 400kHz (See note 1) Copyright © 2009, EM Microelectronic-Marin SA 12/09 – rev D 1.4 3.3 5.0 4 Temp. °C -40 to 85 -40 to 125 -40 to 85 -40 to 125 -40 to 85 -40 to 125 -40 to 85 -40 to 125 -40 to 85 -40 to 125 -40 to 85 -40 to 125 -40 to 85 -40 to 125 -40 to 85 -40 to 125 -40 to 85 -40 to 125 Min Typ 0.6 0.8 0.9 0.6 0.8 0.9 Max 1.5 4.6 2.0 5.2 2.2 5.5 1.5 4.6 2.0 5.2 2.2 5.5 12 15 35 40 50 60 www.emmicroelectronic.com Unit µA µA µA R EM3027 Parameter Dynamic current SPI Interface Low supply detection level1 Low supply detection level2 Switchover hysteresis Symbol IDD Vlow1 Vlow2 Test Conditions SCK = 200 kHz (See Note 2) SCK = 1 MHz (See Note 2) SCK = 1 MHz (See Note 2) Relative to VCC VCC 1.4 3.3 5.0 Relative to VCC Temp. °C -40 to 85 -40 to 125 -40 to 85 -40 to 125 -40 to 85 -40 to 125 Min -40 to 125 -40 to 125 Max 14 18 50 55 65 75 Unit 1.8 2.1 V 1.0 1.4 V Vhyst VCC with respect to VBack = 3.0V 1.4 to 5.0 Input Parameters Low level input voltage High level input voltage VIL VIH CS, CLKOE, SI, SCL/SCK, SDA 1.4 to 5.0 Input Leakage IIN 0.0 < VIN < VCC 1.4 to 5.0 -40 to 85 -40 to 125 1.4 -40 to 125 3.3 -40 to 125 5.0 -40 to 125 1.4 to 5.0 -40 to 85 -40 to 125 -1 -1.5 -40 to 125 -40 to 85 -40 to 125 1.2 Output Parameters Low level output voltage High level output voltage Low level output voltage High level output voltage Low level output voltage High level output voltage Output HiZ leakage on INT Oscillator Start-up voltage Start-up time VOL IOL = 0.4 mA VOH IOH = 0.1 mA VOL IOL = 1.5 mA VOH IOH = 1.5 mA VOL IOL = 5.0 mA VOH IOH = 2.0 mA ILEAK_OUT INT not active VSTA TSTA Frequency stability over voltage Δf/(f ΔV) Input capacitance on X1 CIN Output capacitance on X2 Trickle Charger Current limiting Resistors COUT R80k R20k R5k R1.5k Typ -40 to 125 20 mV 0.2VCC 0.8VCC -1 -1.5 µA 1 1.5 V µA 0.2 V 1.0 0.25 V 2.7 0.8 TSTA < 10s 5.0 1.8V ≤ VCC ≤ 5.5V, TA = +25°C TA = +25°C, f = 32.768kHz, Vmeas = 0.3V (Note 3) TA = +25°C, f = 32.768kHz, Vmeas = 0.3V (Note 3) V 4.5 1 1.5 µA 0.5 1 3 3 V s s 25 0.5 2 ppm/ V 25 13.5 25 13.5 25 25 25 25 80 20 5.0 1.5 -40 to 85 -40 to 125 +/- 1 +/- 1 pF VCC =5.0V, VBack=3.0V VCC =5.0V, VBack=3.0V VCC =5.0V, VBack=3.0V VCC =5.0V, VBack=3.0V kΩ Thermometer Precision TE Vlow1 < VCC ≤ 5.5V +/- 3 +/- 6 Table 7 The following parameters are tested during production test: IDD, Vlow1, Vlow2, VIL, VIH, VOL, VOH, IIN, ILEAK_OUT The parameters ICC, Vhyst, VSTA, TSTA, CIN, COUT, Δf/(f*ΔV), TE are characterised during the qualification of the IC. Notes: 1. SDA = VSS, continuous clock applied at SCL (VIL_SCL < 0.05V, VIH_SCL > 0.95VCC) 2. CS, SI = VCC, continuous clock applied at SCK, SO not connected. (VIL_SCK < 0.05VCC, VIH_SCK > 0.95VCC) Note that there is a 100kΩ pull-down resistor on CS. 3. Vmeas : Peak to peak amplitude during capacitance measurement Copyright © 2009, EM Microelectronic-Marin SA 12/09 – rev D 5 www.emmicroelectronic.com °C R EM3027 4 EM3027 Block Diagram and Application Schematic 4.1 Block Diagram Switchover VBack VHigh Voltage Regulator Voltage Monitoring Vcc Vss VREG X1 Xtal Oscillator Prescaler RTC X2 RAM 32.768 kHz EEPROM Control SCL/SCK SI I2C SPI Inputs Stages CS SDA/SO Thermometer Output Buffers CLKOE SDA/SO INT 4.2 CLKOUT Application Schematic Crystal Layout Example VCC Supply CD X1 VCC for application use X1 CLKOUT Crystal X2 VCC EM3027 CLKOE INT VBack Protection Resistor * X2 CS, SCL/SCK SDA/SO SI CD Lithium Battery or Super Cap VSS µController Serial Interface VSS VSS = 0V * optional for Lithium batteries (<1kΩ) Figure1: Application Schematic Copyright © 2009, EM Microelectronic-Marin SA 12/09 – rev D 6 www.emmicroelectronic.com R EM3027 4.3 Crystal Thermal Behaviour The frequency of the crystal is dependent on the temperature concurring with the following diagram: The following formula expresses a compensation value to be used during frequency correction. 0 ΔF [ppm] FO COMP_val = Qcoef × (T − To) -100 -200 -400 T O-50 TO T O+50 T O+100 T [°C] Temperature [°C] − XtalOffset 2 Qcoef T TO XtalOffset – Thermal quadratic coefficient [ppm/°C ] – Actual temperature [°C] – Turnover temperature [°C] – Crystal offset at TO [ppm] COMP_val – Compensation value result [ppm] The oscillator frequency is adjusted according to the equation above by using coefficients located in the EEPROM control page and the temperature. The actual temperature can be obtained from the internal thermometer or from Temp register updated externally by an application. The principle of the frequency compensation is based on adding/removing of pulses. -300 TO-100 2 Figure 1: Crystal thermal behaviour TO – Turnover temperature [°C] FO – Crystal frequency when TO [Hz] Example 1: Qcoef=0.035; TO=25; XtalOffset=–100 Example 2: Qcoef=0.035; TO=25; XtalOffset=+100 400 [ppm] 600 [ppm] 300 400 200 100 200 Temperature 0 Temperature 0 -50 -50 0 50 100 0 50 100 150 150 -100 -200 -200 -400 -300 Compensation Value Compensation Value Crystal Error Crystal Error -400 -600 Copyright © 2009, EM Microelectronic-Marin SA 12/09 – rev D 7 www.emmicroelectronic.com R EM3027 4.4 Crystal Calibration In order to compensate temperature dependency of the used crystal, correct values of XtalOffset, Qcoef and TO parameters shall be stored in EEPROM Control Page. User is advised to follow these steps in order to compute the parameters in a correct way: 5) 2 2 ferr = -c1(T – c2) + c3 or fO = aT + bT + c. 6) 1) Supply the chip from VCC pin. 2) Set FD0 = FD1 = ‘0’. Set CLKOE pin to ’1’. This provides the uncompensated frequency signal from the crystal oscillator directly on pin CLKOUT. 3) Find a quadratic regression of the measured dependency in form: Then real values of the searched parameters can be obtained from the following relations: Qcoefreal = c1 = -a, T0_real = c2 = -b/(2a), 2 XtalOffsetreal = c3 = c – b /(4a). Measure output frequency fO at different temperatures (at least five measurements in equidistant points in the whole desired temperature range are recommended). Please note that quartz crystal needs few minutes to stabilise its frequency at a given temperature. 7) The values to be stored in EEPROM Control Page have to be corrected in the following way: Qcoef = 4096*(1.05*Qcoefreal), T0 = T0_real - 4, 4) XtalOffset = 1.05*XtalOffsetreal. Compute frequency deviation ferr of output frequency fo from the ideal (target) frequency fL = 32.768Hz in all measured points as follows: ferr = (fo-fL)/fo . Copyright © 2009, EM Microelectronic-Marin SA 12/09 – rev D 8 www.emmicroelectronic.com R EM3027 5 Memory Mapping Address Page Addr [6..3] [2..0] Hex Description Range bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0 Clk/Int TD1 TD0 SROn EERefOn TROn TiOn WaOn 1 0 0 Control Page 00000 000 0x00 OnOffCtrl 001 0x01 IRQctrl Default 0 0 0 0 0 010 0x02 IRQflags ---- SRF V2F V1F TF AF 011 0x03 Status ---- SR VLOW2 VLOW1 100 0x04 RstCtrl ---- 000 0x08 Watch Seconds 0 – 59 BCD Seconds Tens Seconds Units 001 0x09 Watch Minutes 0 – 59 BCD Minutes Tens Minutes Units pm/2 Hours Units Default EEBusy 1 1 0 0 1 SRIntE V2IntE V1IntE TIntE AIntE PON SYSRes Watch Page 00001 0 - 23 BCD 1 - 12 BCD 010 0x0A Watch Hours 011 0x0B Watch Date 1 – 31 BCD 100 0x0C Watch Days 1 – 7 BCD 101 0x0D Watch Months 1 – 12 BCD 110 0x0E Watch Years 0 – 79 BCD 000 0x10 Alarm Seconds 0 – 59 BCD 01 0x11 Alarm Minutes 0 – 59 BCD S12/24 Hours Tens Date Units Date Tens Days Units Months Tens Months Units Years Tens Years Units SecEq Seconds Tens Seconds Units MinEq Minutes Tens Minutes Units 0 - 23 BCD 1 - 12 BCD HourEq pm/2 Hours Units Alarm Page 00010 010 0x12 Alarm Hours 011 0x13 Alarm Date 1 – 31 BCD DateEq 100 0x14 Alarm Days 1 – 7 BCD DayEq Hours Tens Date Tens Date Units Days Units Months Tens Months Units 101 0x15 Alarm Months 1 – 12 BCD MonthEq 110 0x16 Alarm Years 0 – 79 BCD YearEq 000 0x18 Timer low byte 0-255 - - - - - - - - 001 0x19 Timer high byte 0-255 - - - - - - - - 0x20 Temp -60-195 °C - - - - - - - - Years Tens Years Units Timer Page 00011 Temperature Page 00100 000 EEPROM Data Page - Configuration Registers 00101 000 0x28 001 0x29 EEData ---- EEPROM user data (2 bytes) EEPROM Control Page - Configuration Registers EEctrl 00110 000 0x30 XtalOffset 001 0x31 Qcoef 010 0x32 011 0x33 TurnOver ---- R80k R20k R5k R1.5k FD1 FD0 ThEn ThPer Default 0 0 0 0 0 0 1 0 ±121 sign - - - - - - - Default - - - - - - - - ---- - - - - - - - - Default - - - - - - - - 4-67 °C - - - - - - Default - - - - - - RAM Page (User data RAM) 00111 000-111 0x380x3F RAMdata ---- 8 bytes of data Table 8 Unused bit (Read as zero; write has no influence) Copyright © 2009, EM Microelectronic-Marin SA 12/09 – rev D 9 www.emmicroelectronic.com R EM3027 Notes and Settings: - Only pages 0 to 7 are used. Unused pages are for test purposes. The application should not write into unused pages and addresses. - The crystal offset must be set to within ± 121 ppm. - Zero values are read from unused addresses. - Watch, Alarm, Timer pages have to be set by an application before use. - The bit 7 (MSB) of the Alarm registers (SecEq, MinEq.) have to be set to ‘1’ to perform the comparison. (See paragraph 8.3) 6 Definitions of terms in the memory mapping Control Page - Register OnOffCtrl Clk/Int TD0, TD1 SROn EERefOn TROn TiOn WaOn Selects if clock or interrupt is applied onto the IRQ/CLKOUT pin (’0’ = IRQ output; ’1’ = CLKOUT output) – CLKOUT output is the default state after reset Selects decrement rates for Timer (32 Hz after reset) Enables Self-Recovery function (ON after reset) Enables Configuration registers refresh each 1 hour (ON after reset) Enables Timer Auto-reload mode (‘0’ – reload disabled; ‘1’ – reload enabled) Enables Timer (OFF after reset) Enables 1 Hz clock for Watch (ON after initialisation) Control Page - Register IRQctrl SRIntE V2IntE V1IntE TIntE AIntE Self-Recovery interrupt enable VLOW2 interrupt enable VLOW1 interrupt enable Timer interrupt enable Alarm interrupt enable Control Page - Register IRQflags SRF Self-Recovery interrupt flag (bit is set to ‘1’ when Self-Recovery reset is generated) V2F VLOW2 interrupt flag (bit is set to ‘1’ when power drops below Vlow2) V1F VLOW1 interrupt flag (bit is set to ‘1’ when power drops below Vlow1) TF Timer interrupt flag (bit is set to ‘1’ when Timer reaches ZERO) AF Alarm interrupt flag (bit is set to ‘1’ when Watch matches Alarm) NOTE: Flags can be cleared by ‘0’ writing. Control Page - Register Status EEBusy PON SR VLOW2 VLOW1 EEPROM is busy (bit is set to ‘1’ when EEPROM write or Configuration Registers refresh is in progress) (Read Only) Power ON (bit is set to ‘1’ at Power On; clear by ‘0’ writing) Self-Recovery reset or System reset detected (clear by ‘0’ writing) Voltage level VCC or VBack below Vlow2 level (clear by ‘0’ writing) Voltage level VCC or VBack below Vlow1 level (clear by ‘0’ writing) Control Page - Register RstCtrl SYSRes System reset register; writing ‘1’ will initiate restart of the logic (Watch, Alarm and Timer parts excluded). After the restart, status bit SR is set. The register is cleared after restart of the logic. Watch Page - Registers Watch Seconds, Watch Minutes, Watch Hours, Watch Date, Watch Days, Watch Months, Watch Years Watch information (BCD format) S12/24 12-hours or 24-hours format selection; 12-hours: S12/24 = ‘1’, 24-hours: S12/24 = ‘0’ PM/2 S12/24 = ‘0’ PM/2 represents value ‘2’ of tens, S12/24 = ’1’ PM/2 = ‘1’ represents PM (afternoon), PM/2 =’0’ represents AM (morning) Alarm Page - Registers Alarm Seconds, Alarm Minutes, Alarm Hours, Alarm Date, Alarm Days, Alarm Months, Alarm Years Alarm information (BCD format) PM/2 S12/24 = ‘0’ PM/2 represents value ‘2’ of tens, S12/24 = ’1’ PM/2 = ‘1’ represents PM (afternoon), PM/2 =’0’ represents AM (morning) Copyright © 2009, EM Microelectronic-Marin SA 12/09 – rev D 10 www.emmicroelectronic.com R EM3027 Timer Page - Registers TimLow, TimHigh TimLow TimHigh Timer value (Low byte) Timer value (High byte) Temperature Page - Register Temp Temp Temperature (range from -60° C to 190°C with 0°C corresponding to a content of 60d) EEPROM Data Page - Register EEData EEData General purpose EEPROM data bytes EEPROM Control Page - Register EEctrl R80k, R20k, R5k, R1.5k FD0, FD1 ThEn ThPer Selects trickle charger resistors between VHigh and VBack Selects clock frequency at IRQ/CLKOUT pin. Enables thermometer (‘0’ = disabled; ‘1’ = enabled) Selects thermometer activation period (‘0’ = 1 second; ‘1’ = 16 seconds) EEPROM Control Page - Register XtalOffset XtalOffset Crystal frequency deviation at Turnover temperature TO in ppm. Example: value 63d is related to 60 ppm. XtalOffset=1.05*XtalOffsetreal where XtalOffsetreal is real value of crystal frequency deviation at Turnover temperature of the used crystal in ppm. Note: Coefficient 1.05 (exactly 1.048576) is the result of the internally used frequency compensating method. EEPROM Control Page - Register Qcoef Qcoef Thermal quadratic coefficient of the crystal. Example: value 151d is related to 0.035 ppm/°C², Qcoef = 4096 x 1.05 x QCoefreal, where Qcoefreal is real value of thermal quadratic coefficient of the crystal in ppm/°C². EEPROM Control Page - Register TurnOver TurnOver Turnover temperature of the crystal (values 0 to 63d are related to temperature 4 to 67 °C). Example: value 21d is related to 25°C. T0 = T0_real – 4, where T0_real is real value of Turnover temperature of the crystal in °C. RAM Page - Register RAMdata RAMdata General purpose RAM data bytes Copyright © 2009, EM Microelectronic-Marin SA 12/09 – rev D 11 www.emmicroelectronic.com R EM3027 7 Serial communication Depending on the EM3027 version, the serial communication is performed in I2C or SPI mode. When the “Transmission START” is detected, a copy of the content of the addressed Watch-, Alarm-, Timer- and Temperature-register is stored into a cache memory. Data for a following read access are provided from this cache memory. Data in the cache memory are stable until the “Transmission STOP”. A serial communication with the EM3027 starts with a “Transmission START” and terminates with the “Transmission STOP”. “Transmission START” I2C – START condition SPI – CS goes to ‘1’ During a write access, data are written into the cache memory. When the “Transmission STOP” of a WRITE transmission is detected, the content of modified registers in the cache memory is copied back into the Watch-, Alarm, Timer- and/or Temperature-register. “Transmission STOP” I2C – STOP condition SPI – CS goes to ‘0’ 7.1 How to perform data transmission through I2C The I2C protocol is a bidirectional protocol using 2 wires for master-slave communication: SCL (clock) and SDA (data). The two bus lines are driven by open drain outputs and pulled up externally. MSB is sent first. In the EM3027, the upper 5 bits of a register address form a “page address”, the 3 lower bits are an autoincrementing sub-address. The “page-address” is defined by a WRITE transmission. During a transmission, the 3 lower address bits are internally incremented after each data byte. The communication is controlled by the master. To start a transmission, the master applies the START condition and generates the SCL clocks during the whole transmission. The master terminates the transmission by sending the STOP condition. At a READ transmission (R/W = 1), the slave sends data and the master gives the ACK bit(s). The “page-address“ shall be defined by a WRITE transmission, completed with the STOP condition. The first byte contains the 7 bit slave address and the R/W bit. The slave address must correspond to the fixed slave address of the EM3027. After each byte, the receiver outputs an acknowledge bit ACK to confirm correct recept of the byte by a ‘0’ level. The 3 lower address bits are incremented when an ACK is received. If ACK is not received, no auto-increment of the address is executed and a following read outputs data of the same address. At a WRITE transmission (R/W = 0), the master sends slave address, register address and data bytes. The EM3027 works as slave. Its slave address is fixed to ‘1010110’. I2C: Write transmission S Slave Address R/W 1010110 0 ACKs Address ACKs Data Byte (1) ACKs Data Byte (n-1) ACKs Data Byte (n) ACKs P Data byte (n) ACKm P I2C: Read transmission S Slave Address R/W 1010110 0 S ACKs ACKm ... ... ... Slave Address ACKs Address ACKs P S 1010110 start condition sent by the master acknowledge from the receiver (slave) acknowledge from the receiver (master) Copyright © 2009, EM Microelectronic-Marin SA 12/09 – rev D R/W R/W P 12 1 ... ... ACKs Data byte (1) ACKm read/write select (‘0’: master writes data) stop condition www.emmicroelectronic.com R EM3027 A6 SDA A5 A1 A0 R/W ACK D7 D6 D2 D1 D0 ACK Data Byte, send/receive as many as needed Slave Address Read/Write selection bit 1 2 6 7 8 1 9 2 6 7 8 9 SCL Stop Condition Start Condition Figure 2: I2C Communication Noise suppression circuitry is implemented rejecting spikes shorter than 50ns on SCL and SDA bus lines. 7.2 How to perform data transmission through SPI The SPI interface connects master and slave circuits. 4 connections are used: CS = Chip Select, SCK = Serial Clock, SI = Serial Data Input and SO = Serial Data Output. SPI is a byte oriented protocol with MSB first mode. Data are changing on SCK falling edge and sampled on rising edge. A transmission is started by the master by rising the CS input of the selected slave to ‘1’. The transmission is terminated by the master by putting ‘0’ level the CS input. The first bit is the R/W bit, R/W = ‘0’ means a WRITE transmission, where the master sends the data via the SI line. R/W = ‘1’ defines a READ transmission, where the slave outputs the data on the SO line. During a WRITE transmission, the master defines the register address and sends then data bytes, using the auto-increment of the lower address part (bit 2 to 0) within the EM3027. The page address is fixed until a new transmission is started. SO data output of EM3027 is in Hi-Z state during the WRITE transmission. If READ transmission is initiated, data are output after the address byte by the EM3027. The lower part of the address (bit 2 to 0) is automatically incremented after each data byte. The page address is not changed until a new transmission is started. The following 7 bits of the first byte form the address of the register in the EM3027, where the data are written or read. (MSB is first bit at position 2 in this address byte.) th The not transmitted 8 bit of the register address is set internally to ‘0’. SO is in Hi-Z while the address byte is sent. During data output by SO, the SI input has no influence. In the EM3027, the upper 5 bits of an address form a “page address”, the 3 lower bits are an auto-incrementing sub-address. The “page-addres’’ is defined by a WRITE transmission. During a transmission, the 3 lower address bits are incremented internally after each byte. SO and SI can be connected together to form a 3-wire interface with CS, SCK and Serial Data Input/Output. Copyright © 2009, EM Microelectronic-Marin SA 12/09 – rev D 13 When CS is at ‘0’ level, SO is Hi-Z and SCK, SI can be left floating. The EM3027 works as slave. The CS input has a pulldown resistor of 100 kΩ. www.emmicroelectronic.com R EM3027 Transmission Start Transmission Stop CS SCK SI R/W A6 A5 A4 A3 A2 A1 A0 D7 D6 D1 D0 HiZ SO Figure 3: SPI Write Transmission Transmission Start Transmission Stop CS SCK SI SO R/W A6 A5 A4 A3 A2 A1 A0 HiZ D7 D6 D1 D0 HiZ Figure 4: SPI Read Transmission Copyright © 2009, EM Microelectronic-Marin SA 12/09 – rev D 14 www.emmicroelectronic.com R EM3027 8 Functional Description 8.1 Start after power-up A The chip is in reset state when the supply voltage is below an internal threshold level (PON in Status register 0x03 goes to ‘1’). When the supply level is higher than this threshold voltage, the reset is released. B When the supply voltage is higher than the oscillator start-up voltage, the basic clocks for Watch and control logic become active after the oscillator start time. C With clocks present, the voltage detector starts in fast mode to measure the supply voltage. When a voltage higher than Vlow2 is detected, the fast detection mode is stopped and the EEPROM read is enabled. D Configuration registers are loaded with the configuration data read from the EEPROM (Addresses from 0x28 to 0x33). E If thermometer is enabled (ThEn=’1’ and VLOW1=’0’), temperature is measured and compensation value for frequency correction evaluated. F The EM3027 starts its normal function, depending on the supply voltage level applied. 8.2 Normal Mode function The chip has following functions in Normal Mode: 8.3 1. Voltage detection – The voltage detection is executed each second. 2. Temperature measurement – It is executed, if thermometer is enabled (ThEn=’1’) and VLOW1=’0’. 3. Frequency compensation – The compensation of the oscillator frequency works continuously. 4. Configuration Registers refresh – The EEPROM is read each hour to refresh the content of the configuration registers (supply voltage must be above Vlow2 for EEPROM read). 5. Watch/Alarm – The Watch function is continuously active, whereas the Alarm function depends on its activation. 6. Timer – Is active when enabled. 7. Self-Recovery system – Is enabled by default (can be disabled by the application). 8. Serial interface – The communication works if VCC > VCC_min and VCC > VBack . Watch and Alarm function The Watch part provides timing information in BCD format. The timing data is composed of seconds, minutes, hours, date, weekdays, months and years. The corresponding values are updated every second. The Watch part setup is provided by Write transmission into the Watch Page (Address 0x08h to 0x0Eh). After the transmission, the Watch is restarted from the setup values after one second. The Alarm function is activated by setting and enabling the alarm registers (Address 0x10h to 0x16h). Each Alarm byte has its own enable bit. It is the bit 7. Recommended combinations of enabled bits are described in the table below. SecEq 1 1 1 1 1 1 MinEq 0 1 1 1 1 1 HrsEq DateEq DaysEq MonthEq 0 0 0 0 0 0 0 0 1 0 0 0 1 1 0 0 1 1 0 1 1 0 1 0 Table 9: Alarm Period Selection YearEq 0 0 0 0 0 0 Al_period min hrs day month year week - Both Watch and Alarm parts must be set by an application before use - The bits SecEq to YearEq enable the comparison of the corresponding registers Copyright © 2009, EM Microelectronic-Marin SA 12/09 – rev D 15 www.emmicroelectronic.com R EM3027 8.4 Timer function The 16-bit count down timer can be enabled/disabled by TiOn bit. The timer input frequency is selected by TD1, TD0 bits according to the following table: TD1 TD0 Timer frequency 0 0 32 Hz 0 1 8 Hz 1 0 1 Hz 1 1 0.5 Hz Table 10: Timer Frequency Selection The timer can run in Zero-Stop or Auto-Reload mode (TROn bit: ‘0’ = Zero-Stop mode, ‘1’ = Auto-Reload mode). When TROn = ‘0’, then it is possible to read current value of the timer. If TROn = ‘1’, then last written value is read from cache memory. The value in the cache memory is used as the new value for reloading (Auto-Reload mode). Frequency selection (TD1, TD0) and mode selection (TROn) can be written only when the timer is stopped (TiOn = ‘0’). Timer values (TimLow, TimHigh) can be written only when TiOn = ’0’ and TROn = ‘0’. NOTE: The “Timer Page” can also be used as a general purpose register when the timer function is not used. 8.5 Temperature measurement The integrated thermometer has a resolution of 1°C. The thermometer is disabled when ThEn = ’0’ and enabled when ThEn = ’1’. By default, the thermometer is enabled. Thermometer period is selectable by ThPer bit according to the table below: ThPer Period in Seconds 0 1s 1 16 s Table 11: Thermometer Period The thermometer is automatically disabled when VLOW1 status bit is at ‘1’. When the thermometer is disabled (ThEn = ’0’), the Temp register can be written. Temp register uses a cache memory to keep stable value during a whole transaction (read/write). 8.6 Frequency compensation There is a frequency compensation unit (FCU) inside EM3027. FCU compensates quartz crystal native frequency in dependency on actual compensation value (COMP_val). FCU is always running. During chip power-up, if ThEn = ’1’ and VLOW1 = ‘0’ temperature measurement is enabled and COMP_val is computed. Otherwise, COMP_val is set to 0 ppm. In Normal mode, new compensation value is computed each 32 seconds. The only exception is when ThEn = ‘1’ and VLOW1 = ‘1’. In this case, temperature measurement and COMP_val computation are blocked and FCU uses the last computed compensation value. For the evaluation of COMP_val, actual content of Temp register (0x20) is used. The compensation value is computed according to the equation described in paragraph 4.3. Content of Temp register is updated either after a temperature measurement (when ThEn = '1' and VLOW1 = '0') or after Temp register write transaction (when ThEn = '0'). After power-up content of Temp register is undefined. If thermometer is disabled (ThEn = '0') user is advised to periodically update Temp register with actual ambient temperature in order to have correct input data for COMP_val computation. Copyright © 2009, EM Microelectronic-Marin SA 12/09 – rev D 16 www.emmicroelectronic.com R EM3027 8.7 EEPROM memory Before any EEPROM access (read/write), the bit EERefOn has to be cleared by the application to prevent from access collision with the Configuration Registers. Then the application has to read EEBusy bit and if EEBusy = ‘0’, then EEPROM access can be started. After the write command (at “Transmission STOP”) the current state of EEPROM writing is monitored by EEBusy register bit at ‘1’. EEBusy goes to ‘0’ when EEPROM writing is finished. NOTE: VCC must be applied during the whole EEPROM write (i.e. until EEBusy = ‘0’) and must be higher than Vprog. Clear EERefOn Clear EERefOn No No EEBusy = 0 ? Yes Yes Write EEPROM Read EEPROM Yes EEBusy = 0 ? No Next read ? EEBusy = 0 ? Yes No Set EERefOn Yes Next Write ? No Set EERefOn 8.7.1 EEPROM Control Page This part is composed of 4 bytes purposed for miscellaneous function control and for crystal compensation constants. EEctrl byte contains: trickle charger selectors (R80k, R20k, R5k, R1.5k); output clock frequency selector (FD1, FD0); thermometer enable and thermometer period selector. 8.7.2 Clock Output Output clock frequency is selected by FD1, FD0 bits in EEctrl register. FD1 0 FD0 0 0 1 1 1 0 1 Select Clock Output Description From crystal oscillator, without frequency compensation 32.768 kHz 1024 Hz With frequency compensation 32 Hz 1 Hz Table 12: Output Clock frequency selection Copyright © 2009, EM Microelectronic-Marin SA 12/09 – rev D 17 www.emmicroelectronic.com R EM3027 8.7.3 Configuration Registers All the configuration data from EEPROM (i.e. EEctrl, XTalOffset, Qcoef, TurnOver, EEData) is hold in configuration registers. Data from EEPROM is loaded to these registers during power-up sequence and is refreshed each hour, if ‘Configuration Registers refresh’ feature is enabled (EERefOn = ‘1’). Regular refresh of Configuration Registers prevents their content to be corrupted by strongly polluted electrical environment (EMC problems, disturbed power supply, etc.). It is recommended to enable ‘Configuration Registers refresh’ feature. 8.7.4 EEPROM User Memory Two bytes of the memory are dedicated for the application (addresses 0x28 and 0x29). 8.8 RAM User Memory RAM user memory size is 8 bytes (addresses 0x38 to 0x3F). The state of the RAM data after power-up is undefined. 8.9 Status Register The purpose of EEBusy bit is to inform the user about current status of the EEPROM operations. EEBusy – status of EEPROM controller (if EEBusy = ‘1’, then Configuration Registers refresh or EEPROM write is in progress) The purpose of the following status bits is to record status of power supply voltage and Self-Recovery system/System reset behaviour. PON VLOW1 VLOW2 SR – status of Power-ON – status of Vlow1 voltage detection – status of Vlow2 voltage detection – status of the Self-Recovery system/System reset If one of these status bits is set, it can be cleared only by writing ‘0’, there is no automatic reset if the set condition disappears. 8.10 Interrupts There are five interrupt sources which can output an interrupt on (INT and/or IRQ/CLKOUT) pins. The request is generated when at least one of IRQflags goes to ‘1’ (OR function). AF TF V1F V2F SRF – interrupt is provided when Watch time reaches Alarm time settings and comparison is enabled – interrupt is provided when Timer reaches ZERO – interrupt is provided when supply voltage is below Vlow1 (when VLOW1 status bit is set) – interrupt is provided when supply voltage is below Vlow2 (when VLOW2 status bit is set) – interrupt is provided when Self-Recovery system invoked internal reset (when SR status bit is set) Each interrupt source has its own interrupt enable (AIntE, TIntE, V1IntE, V2IntE, SRIntE). When the interrupt enable is ‘1’ then the appropriate interrupt source is enabled. Interrupt flags (IRQflags) are cleared by ‘0’ writing into the appropriate bit. In case of V1F, V2F and SRF bits, it is necessary to clear also the corresponding status bits (Status) after interrupt bit. Copyright © 2009, EM Microelectronic-Marin SA 12/09 – rev D 18 www.emmicroelectronic.com R EM3027 8.11 Self-Recovery System (SRS) The purpose of the Self-Recovery System (SRS) is to generate an internal reset in case the on-chip state machine goes into a deadlock. The function is based on an internal counter that is periodically reset by the control logic. If the counter is not reset on time, this reset will take place. It is executed after two voltage monitoring periods at the latest, i.e. 2s or 32s (ThPer bit). A possible source of a deadlock could be disturbed electrical environment (EMC problem, disturbed power supply, etc.). SRS sets status bit SR and resets the internal logic, except Watch, Alarm and Timer parts (i.e. time informations are not affected). Furthermore, if the SRS interrupt is enabled (SRIntE='1'), the SRF flag is set after the internal chip reset. Note, that SROn = '1' and SRIntE = '0' after the reset. After the internal reset, the device starts with the power-up sequence (see paragraph 8.1). SRS is automatically enabled after power-up (SROn bit). It can be disabled by writing '0' into the SROn bit in the Control Page. 8.12 Register Map The address range of the EM3027 is divided into pages. The page is addressed by the five most significant bits of the address (bits 6 … 3). The three low significant bits of the address provide selection of registers inside the page. During address incrementing the three low significant bits (2 … 0) are changed. The page address part is fixed during the whole data transmission. 8.13 Crystal Oscillator and Prescaler The 32.768 kHz crystal oscillator and the clock divider provide the timing signals for the functional blocks. The prescaler block is responsible for frequency division of the 32.768 kHz clock signal from the crystal oscillator. Divided frequency is then distributed between other blocks inside the chip, including Watch, Timer and control logic. Two capacitors CIN and COUT are integrated on chip – see Figure 5. X2 X1 CIN COUT Figure 5: Oscillator Capacitors Copyright © 2009, EM Microelectronic-Marin SA 12/09 – rev D 19 www.emmicroelectronic.com R EM3027 9 Power Management VCC Switchover I/O V H igh 4x Trickle charger resistors V Back V Reg Logic, EEPROM, Thermometer, Voltage Monitor Regulator 2.9V Xtal Oscillator Figure 6: Power Management 9.1 Power Supplies, Switchover and Trickle Charger The device can be supplied from the VCC pin or from the VBack pin. In this way, a rechargeable battery or a super-cap can be charged from the VCC voltage, as long as VCC > VBack. The switchover block implemented inside the chip compares VCC and VBack voltages and connects the higher of them to the internal VHigh net that supplies the chip. There are 4 selectable resistors connected in parallel with typical values of 80kΩ, 20kΩ, 5kΩ and 1.5kΩ. One or more resistors can be selected by EEctrl bits setting. Nevertheless, the communication pins (SCL, SDA or CS, SCK, SI, SO) are supplied from the VCC pin. For that reason, when serial interface (I2C or SPI) is used, the chip has to be supplied from VCC. (i.e. VCC > VBack). By setting of a trickle charger bit in register EEctrl, a resistor can be inserted between VBack and VHigh voltage. If a Lithium battery shall be connected to VBack pin, a protection resistor of value up to 1kΩ can be connected in series with it. In this way, in case of EM3027 device damage resulting in short between both supply pins, charging current from the VCC supply can be reduced to its allowed maximum level as required by UL1642 standard. Clock operating with thermocompensation using either previously in fully operating mode measured or by user stored temperature value; no EEPROM write Vlow2 Serial communication is enabled, if VCC > VCCmin and VCC > Vback min max Vlow1 min max Vprog VCCmin VCCmax EEPROM write if VCC > Vprog 1.4V 0V EM3027 fully operating according datasheet (clock, thermometer, thermocompensation) 5.5V 2.2V 1.0V 2.0V 3.0V 4.0V 5.0V Supply Voltage Figure 7: EM3027 operating Voltage Areas Copyright © 2009, EM Microelectronic-Marin SA 12/09 – rev D 20 www.emmicroelectronic.com R EM3027 9.2 Low Supply Detection The supply voltage level is monitored periodically versus Vlow1 and Vlow2 levels. The monitoring rate is one second. When the voltage monitoring is running, a higher current consumption for few milliseconds occurs. At the power-up of the device, as long as the supply voltage stays below Vlow2, the monitoring rate is accelerated. To enable normal operation, the chip must be supplied with a voltage above Vlow2, to enable the readout of initialization data from EEPROM and to stop the higher current consumption. When the supply voltage drops from the normal range (from 2.1V to 5.5V) below Vlow1, the VLOW1 status bit is set to ‘1’ by the voltage monitoring system. When bit VLOW1 is at ‘1’, the thermometer is disabled and the automatic computation of the thermal compensation value (COMP_val) for frequency correction is inhibited. In this case, the last computed compensation value is used. Copyright © 2009, EM Microelectronic-Marin SA 12/09 – rev D To leave the VLOW1 status, the supply voltage must be increased above the Vlow1 level and a ‘0’ value must be written into the VLOW1 status bit via the serial interface. When the supply voltage drops below the Vlow2 level, the VLOW2 status bit is set by the voltage monitoring system. The VLOW2 status bit disables the read out of the EEPROM. To leave the VLOW2 status, the supply voltage must be increased above the Vlow2 level and a ‘0’ value must be written into the VLOW2 status bit via the serial interface. Below Vlow2 level, device functionality is not guaranteed and register contents can be corrupted. Therefore, if VLOW2 status bit is set, it is recommended to perform system reset by writing of ‘1’ into SYSRes bit in RstCtrl page and afterwards update content of Watch, Alarm and Timer registers. 21 www.emmicroelectronic.com R EM3027 10 AC Characteristics 10.1 AC characteristics – I2C VSS = 0V and TA=-40 to +125°C, unless otherwise specified PARAMETER SYMBOL SCL Clock Frequency fSCL CONDITIONS MIN Hold Time (Repeated) START Condition tBUF MAX Vcc ≥ 3.0V 400 Vcc >1.8V 300 UNITS kHz 100 Vcc>1.4V Bus Free Time Between STOP and START Condition TYP Vcc ≥ 3.0V 0.4 Vcc >1.8V 0.5 Vcc>1.4V 1.0 μs Vcc ≥ 3.0V tHD:STA 0.2 Vcc >1.8V μs Vcc>1.4V LOW Period of SCL Clock HIGH Period of SCL Clock Setup Time START Condition Data Hold Time Data Setup Time Data Valid Time Data Valid Acknowledge Time Rise Time of Both SDA and SCL Signals Fall Time of Both SDA and SCL Signals (See note 1) tLOW tHIGH tSU:STA tHD:DAT tSU:DAT tVD:DAT tVD:ACK tR tF Vcc ≥ 3.0V 1.3 Vcc >1.8V 1.7 Vcc>1.4V 4.5 Vcc ≥ 3.0V 0.4 Vcc >1.8V 0.5 Vcc>1.4V 0.6 Vcc ≥ 3.0V 20 Vcc >1.8V 30 Vcc>1.4V 50 Vcc ≥ 3.0V 20 Vcc >1.8V 30 Vcc>1.4V 50 Vcc ≥ 3.0V 50 Vcc >1.8V 80 Vcc>1.4V 100 Vcc ≥ 3.0V 1.2 Vcc >1.8V 1.5 Vcc>1.4V 4.0 Vcc ≥ 3.0V 0.9 Vcc >1.8V 1.1 Vcc>1.4V 3.5 tSU:STO μs ns ns ns μs μs Vcc ≥ 3.0V 200 Vcc >1.8V 300 Vcc>1.4V 1000 Vcc ≥ 3.0V 200 Vcc >1.8V 300 ns ns 400 Vcc>1.4V Setup Time (Repeated) STOP Condition μs Vcc ≥ 3.0V 20 Vcc >1.8V 30 Vcc>1.4V 50 ns Length of spikes suppressed by the input filter on SCL and SDA Capacitive Load For Each Bus Line tSP 50 CB 200 pF I/O Capacitance (SDA, SCL) CI/O 10 pF ns Table 13: I2C AC characteristics Parameters are guaranteed by design. They are not tested in production. Copyright © 2009, EM Microelectronic-Marin SA 12/09 – rev D 22 www.emmicroelectronic.com R EM3027 Calculation of external pull–up resistor The following conditions have to be met: Rise time is equal to 0.847 RPU (CB + N * CI/O) ⇒ RPU < tR max / (0.847 (CB + N CI/O)), where N is total number of I/O pins connected to the corresponding bus line. (tR in ns, C in pF, R in kΩ) The minimum value of the pullup resistor value can be calculated with the IOL value of the SDA output: RPU = (Vcc – VOL) / IOL ( IOL: see Table 7, page 5, Output Parameters; e.g. 5mA at VCC = 5.0V, with VOL = 0.8V ) Start Stop SDA tBUF tHIGH tLOW tR SCL tHD:STA tHD:DAT tF tSU:STO tSU:DAT tSU:STA Figure 8: I2C Timing 10.2 I2C Specification compliance EM3027 device with I2C serial interface was designed 2 in compliance with Philips Semiconductors I C-bus specification UM10204 (Rev. 03 – 19 June 2007), Fastmode class (up to 400kbit/s). Device address consists of 7 bits. Clock stretching is not supported. Brief manual to I2C interface read and write transmissions is to be found in §7.1. Copyright © 2009, EM Microelectronic-Marin SA 12/09 – rev D There are, however, the following discrepancies between I2C specification and EM3027 interface: 1) Falling time on SDA driven by EM3027 can be shorter than 20 + 0.1* CB ns. (CB is total capacitive load for SDA bus line in pF) In other words, slope control of falling edges on SDA is missing. 2) Some timing parameters differ from the original I2C specification – refer to Table 13. 23 www.emmicroelectronic.com R EM3027 10.3 AC characteristics – SPI VSS = 0V and TA=-40 to +125°C, unless otherwise specified PARAMETER SYMBOL CONDITIONS fSCK SCK Clock Frequency Data to SCK setup tDC MIN TYP MAX UNITS Vcc ≥ 3.0V 1 MHz Vcc >1.8V 600 Vcc >1.4V 200 kHz Vcc ≥ 3.0V Vcc >1.8V 20 ns Vcc >1.4V SCK to Data Hold tCDH SCK to Data Valid tCDD SCK Low Time tCL SCK High Time tCH SCK Rise and Fall tR , tF Vcc ≥ 3.0V 200 Vcc >1.8V 300 Vcc >1.4V 500 Vcc ≥ 3.0V 350 Vcc >1.8V 650 Vcc >1.4V 1300 Vcc ≥ 3.0V 400 Vcc >1.8V 700 Vcc >1.4V 1500 Vcc ≥ 3.0V 400 Vcc >1.8V 700 Vcc >1.4V 1500 Vcc ≥ 3.0V ns ns 800 Vcc >1.4V tCC ns 200 Vcc >1.8V CS to SCK Setup ns ns Vcc ≥ 3.0V Vcc >1.8V 100 ns Vcc >1.4V SCK to CS Hold tCCH CS Inactive Time tCWL CS to Output High Impedance tCDZ Vcc ≥ 3.0V 200 Vcc >1.8V 300 Vcc >1.4V 500 Vcc ≥ 3.0V 200 Vcc >1.8V 300 Vcc >1.4V 400 Vcc ≥ 3.0V ns ns 50 Vcc >1.8V 100 Vcc >1.4V 200 ns Table 14: SPI AC characteristics Parameters are guaranteed by design. They are not tested in production. 1) Max. bus capacitance on SO line shall be lower than 100pF when Vcc > 1.8V and lower than 50pF when Vcc < 1.8V. 2) Spikes on SCK signal shorter than 20ns are suppressed. Copyright © 2009, EM Microelectronic-Marin SA 12/09 – rev D 24 www.emmicroelectronic.com R EM3027 CS tF tCC tCH t tCCH tCL tCWL SCK tDC tCDH A0 R/W SI SI data are don't care when SO outputs data tCDD SPI Master writes address, EM3027 outputs data: HiZ SO tCDZ D0 D7 Figure 9: SPI Read Timing CS tF tCC tCH t tCCH tCL tCWL SCK tDC SI tCDH R/W A0 D7 D0 SPI Master writes address and data: SO HiZ Figure 10: SPI Write Timing Copyright © 2009, EM Microelectronic-Marin SA 12/09 – rev D 25 www.emmicroelectronic.com R EM3027 11 Package Information 11.1 TSSOP-08/14 4 B 1.00 1.00 DIA. 3 2 1 C B B E/2 1.00 E C L E1 5 N 0.20 C A-B D 2X N/2 TIPS e/2 7 4 SEE DETAIL "A" D A 4 b bbb M C A-B A2 ODD LEAD SIDES TOPVIEW TOPVIEW D 9 0.05 C 0.25 PARTING LINE A H C e A1 H D 5 C aaa 3 X = A AND B (14°) EVEN LEAD SIDES END VIEW TOP VIEW X X L 6 8 SEATING PLANE (1.00) DETAIL 'A' (14°) (VIEW ROTATED 90° C.W.) S Y M B O L A A1 A2 aaa b b1 bbb c c1 D E1 e E L N P P1 COMMON DIMENSIONS MIN. NOM. 0.05 0.85 0.90 0.076 0.19 0.19 0.22 0.10 0.09 0.09 0.127 SEE VARIATIONS 4.30 4.40 0.65 BSC 6.40 BSC 0.50 0.60 SEE VARIATIONS SEE VARIATIONS SEE VARIATIONS 0° NOTE MAX. 1.10 0.15 0.95 0.30 0.25 0.20 0.16 4.50 0.70 8° ALL DIMENSIONS IN MILLIMETERS Copyright © 2009, EM Microelectronic-Marin SA 12/09 – rev D N VARIO T E ATIONS 9 MIN. 2.90 4.90 5 D NOM. 3.00 5.00 MAX. 3.10 5.10 P MAX. 1.59 3.1 P1 MAX. 3.2 3.0 7 N 8 14 NOTES: 1. DIE THICKNESS ALLOWABLE IS 0.279±0.0127 2. DIMENSIONING & TOLERANCES PER ASME. Y14.5M-1994. 3. DATUM PLANE H LOCATED AT MOLD PARTING LINE AND COINCIDENT WITH LEAD, WHERE LEAD EXITS PLASTIC BODY AT BOTTOM OF PARTING LINE. 4. DATUM A-B AND D TO BE DETERMINED WHERE CENTERLINE BETWEEN LEADS EXITS PLASTIC BODY AT DATUM PLANE H. 5 5 5. "D" & "E1" ARE REFERENCE DATUM AND DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS, AND ARE MEASURED AT THE BOTTOM PARTING LINE. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.15mm ON D AND 0.25mm ON E PER SIDE. 6. DIMENSION IS THE LENGTH OF TERMINAL FOR SOLDERING TO A SUBSTRATE. 6 7 7. TERMINAL POSITIONS ARE SHOWN FOR REFERENCE ONLY. 8. FORMED LEADS SHALL BE PLANAR WITH RESPECT TO ONE ANOTHER WITHIN 0.076mm AT SEATING PLANE. 9. THE LEAD WIDTH DIMENSION DOES NOT INCLUDE DAMBAR PROTRUSION. ALLOWABLE DAMBAR PROTRUSION SHALL BE 0.07mm TOTAL IN EXCESS OF THE LEAD WIDTH DIMENSION AT MAXIMUM MATERIAL CONDITION. DAMBAR CANNOT BE LOCATED ON THE LOWER RADIUS OR THE FOOT. MINIMUM SPACE BETWEEN PROTRUSIONS AND AN ADJACENT LEAD SHOULD BE 0.07mm 26 www.emmicroelectronic.com R EM3027 11.2 SO-8 Copyright © 2009, EM Microelectronic-Marin SA 12/09 – rev D 27 www.emmicroelectronic.com R EM3027 12 Ordering Information EM3027 I D X SO8B Part Number EM3027 = Package RTC Interface SO8B= 8 pin SO8 tape TP8B= 8 pin TSSOP8 tape I2C bus = I TP14= 14 pin TSSOP14 tape SPI bus = S WS11= Wafer sawn 11 MILS Temperature compensation Functional Temperature D Default Temp. Compensation = Standard temperature= S Extended temperature= X (Factory Standard) Standard Versions Part Number Package EM3027IDSTP8A+ EM3027IDSTP8B+ EM3027IDXTP8B+ EM3027IDSSO08A+ EM3027IDSSO08B+ EM3027IDXSO08B+ EM3027SDSTP14A+ EM3027SDSTP14B+ EM3027SDXTP14B+ TSSOP8 TSSOP8 TSSOP8 SO8 SO8 SO8 TSSOP14 TSSOP14 TSSOP14 Functional Temperature -40 +85°C -40 +85°C -40 +125°C -40 +85°C -40 +85°C -40 +125°C -40 +85°C -40 +85°C -40 +125°C Interface I2C I2C I2C I2C I2C I2C SPI SPI SPI Delivery Form Marking Stick , 100 pcs Tape & Reel, 4000 pcs Tape & Reel, 4000 pcs Stick, 97 pcs Tape & Reel, 2500 pcs Tape & Reel, 2500 pcs Stick, 96 pcs Tape & Reel, 3500 pcs Tape & Reel, 3500 pcs 3027S5 3027S5 3027X5 3027S5 3027S5 3027X5 3027S6 3027S6 3027X6 Please contact Sales office for other versions not shown here and for availability of non standard versions. EM Microelectronic-Marin SA (EM) makes no warranty for the use of its products, other than those expressly contained in the Company's standard warranty which is detailed in EM's General Terms of Sale located on the Company's web site. EM assumes no responsibility for any errors which may appear in this document, reserves the right to change devices or specifications detailed herein at any time without notice, and does not make any commitment to update the information contained herein. No licenses to patents or other intellectual property of EM are granted in connection with the sale of EM products, expressly or by implications. EM's products are not authorized for use as components in life support devices or systems. Copyright © 2009, EM Microelectronic-Marin SA 12/09 – rev D 28 www.emmicroelectronic.com