High Reliability Series Serial EEPROMs WL-CSP EEPROM family I2C BUS BU9844GUL-W No.10001EAT18 ●Description 2 BU9844GUL-W series is a serial EEPROM of I C BUS interface method. 1.7V single power source action and actions available at 400kHz. ●Features 2 1) Completely conforming to the world standard I C BUS. All controls available by 2 ports of serial clock (SCL) and serial data(SDA) 2) Other devices than EEPROM can be connected to the same port, saving microcontroller port. 3) Actions available at 400kHz clock (1.7V～5.5V) 4) 1.7～5.5V single power source action most suitable for battery use. 5) Page write mode useful for initial value write at factory shipment. 6) Auto erase and auto end function at data rewrite. 7) Low current consumption At write action (5V) : 1.2mA (Typ.) At read action (5V) : 0.2mA (Typ.) At standby action (5V) : 0.1μA (Typ.) 8) Write mistake prevention function Write (write protect) function added. Write mistake prevention function at low voltage. 9) Data rewrite up to 1,000,000times. 10) Data kept for 40 years. 11) Noise filter built in SCL / SDA terminal 12) Shipment data all address FFh. ●Page write Product number Number of pages 16Byte BU9844GUL-W ●BU9844GUL-W Type BU9844GUL-W Capacity Bit format Power source voltage Package 16Kbit 2048×8 1.7~5.5V VCSP50L1 Symbol Ratings Unit Vcc -0.3~+6.5 V ●Absolute maximum ratings (Ta=25℃) Parameter Impressed voltage Permissible dissipation Pd 220 *1 mW Storage temperature range Tstg -65~125 ℃ Operating temperature range Topr -40~85 ℃ - -0.3~Vcc+1.0 V Terminal voltage * When using at Ta=25℃ or higher, 2.2mW (*1) to be reduced per 1℃ ●Recommended action conditions Parameter Power source voltage Input voltage www.rohm.com © 2010 ROHM Co., Ltd. All rights reserved. Symbol Ratings Vcc 1.7~5.5 Vin 0~Vcc 1/18 Unit V 2010.09 - Rev.A Technical Note BU9844GUL-W ●Memory cell characteristics (Ta=25℃, Vcc=1.7~5.5V) Limits Parameter Min Typ. Number of data rewrite times *1 Data hold years Max Unit 1,000,000 - - Times 40 - - Years *1 Not 100% TESTED ●Electrical characteristics (Unless otherwise specified, Ta=-40~+85℃, Vcc=1.7~5.5V) Limits Parameter Symbol Min. Typ. Max. Unit Conditions “HIGH” input voltage1 VIH1 0.7Vcc - - V 2.5V≦Vcc≦5.5V “LOW” Input voltage1 VIL1 - - 0.3Vcc V 2.5V≦Vcc≦5.5V “HIGH” input voltage2 VIH2 0.9Vcc - - V 1.7V≦Vcc＜2.5V “LOW” input voltage2 VIL2 - - 0.1Vcc V 1.7V≦Vcc＜2.5V “LOW” output voltage1 VOL1 - - 0.3 V IOL=3.0mA, 2.5V≦Vcc≦5.5V, (SDA) “LOW output voltage2 VOL2 - - 0.2 V IOL=1.5mA, 1.7V≦Vcc＜2.5V, (SDA) Input leak current ILI -1 - 1 μA VIN=0V~Vcc Output leak current ILO -1 - 1 μA VOUT=0V~Vcc(SDA) ICC1 - - 2.0 mA Vcc=5.5V, fSCL=400kHz, tWR=5ms, Byte write, Page write ICC2 - - 0.5 mA Vcc=5.5V, fSCL=400kHz Random read, Current read, sequential read ISB - - 2.0 μA Vcc=5.5V, SDA·SCL=Vcc, A2=GND, WP=GND Current consumption at action Standby current ○This product is not designed for protection against radioactive rays. www.rohm.com © 2010 ROHM Co., Ltd. All rights reserved. 2/18 2010.09 - Rev.A Technical Note BU9844GUL-W ●Action timing characteristics (Unless otherwise specified, Ta=-40～+85℃, Vcc=1.7～5.5V) Parameter FAST-MODE 2.5V≦Vcc≦5.5V Symbol STANDARD-MODE 1.7V≦Vcc≦5.5V Min. Typ. Max. Min. Typ. Max. Unit SCL frequency fSCL - - 400 - - 100 kHz Data clock “HIGH” time tHIGH 0.6 - - 4.0 - - μs Data clock “LOW” time tLOW 1.2 - - 4.7 - - μs SDA, SCL rise time *1 tR *1 - - 0.3 - - 1.0 μs SDA< SCL fall time *1 tF *1 - - 0.3 - - 0.3 μs Start condition hold time tHD:STA 0.6 - - 4.0 - - μs Start condition setup time tSU:STA 0.6 - - 4.7 - - μs Input data hold time tHD:DAT 0 - - 0 - - ns Input data setup time tSU:DAT 100 - - 250 - - ns tPD 0.1 - 0.9 0.2 - 3.5 μs Output data delay time Output data hold time tDH 0.1 - - 0.2 - - μs tSU:STO 0.6 - - 4.7 - - μs Bus release time before transfer start tBUF 1.2 - - 4.7 - - μs Internal write cycle time tWR - - 5 - - 5 ms tI - - 0.1 - - 0.1 μs Stop condition setup time Noise removal valid period (SDA, SCL terminal) WP hold time tHD:WP 0 - - 0 - - ns WP setup time tSU:WP 0.1 - - 0.1 - - μs WP valid time tHIGH:WP 1.0 - - 1.0 - - μs *1 Not 100% tested. ●Sync data input / output timing tR tF tHIGH SCL SCL tHD:STA tSU:DAT tLOW DATA(1) tHD:DAT SDA (Input) SDA tBUF tPD D1 DATA(n) D0 ACK ACK ｔWR tDH stop condition WP SDA (Output) ○Input read at the rise edge of SCL ○Data output in sync with the fall of SCL tSU：WP ｔHD：WP fig.1-(d) WP timing at write execution Fig.-1(a) Sync data input / output timing SCL SCL tSU:STA tHD:STA DATA(n) DATA(1) tSU:STO SDA SDA D1 D0 ACK ACK tHIGH:WP START BIT STOP BIT Fig.1-(b) Start – stop bit timing D0 ACK tWR Write data (n-th address) Stop condition Fig.1-(e) WP timing at write cancel ○At write execution, in the area from the DO taken clock rise of the first DATA (1), to tWR, set WP=”LOW” ○By setting WP “HIGH” in the area, write can be cancelled. When it is set WP=”HIGH” during tWR, write is forcibly ended, and data of address under access is not guaranteed, therefore write it once again. SCL SDA tWR WP Start condition Fig.1-(c) Write cycle timing www.rohm.com © 2010 ROHM Co., Ltd. All rights reserved. 3/18 2010.09 - Rev.A Technical Note BU9844GUL-W ●Block diagram VCC 16Kbit EEPROM array GND 8bit 9bit Address decoder Slave – word address register 9bit START A2 Data register WP STOP SCL Control circuit ACK High voltage generating circuti Power source voltage detection SDA Fig.2 Block diagram ●Pin assignment and description C2 C1 ○ ○ B1 B2 ○ ○ A1 A2 ○ ○ C B A 1 INDEX post 2 Fig.3 BU9844GUL-W(bottom view) Land No. Terminal name Input/ Output A1 VCC － A2 A2 Input Power Supply Out of Use (Vcc or GND or OPEN) B1 WP Input Write Protect Input B2 GND Input Ground （0V） C1 SCL Input C2 SDA Function Serial Clock Input Input /Output Slave and Word Address, Serial Data Input, Serial Data Output *1 *1 An open drain output requires a pull-up resistor. 6 5 5 4 4 SPEC 3 2 0.8 Ta=85℃ 3 Ta=-40℃ 2 Ta=85℃ Ta=-40℃ 1 1 VOL2[V] 6 VIL1,2,3[V] VIH1,2,3[V] ●Characteristic data (The following values are Typ. ones.) SPEC SPEC Ta=-40℃ 0 0 2 3 4 5 Ta=85℃ 0.2 Ta=25℃ 1 Ta=25℃ 0.4 Ta=25℃ 1 0 0 0.6 6 Vcc[V] Fig.4 H input voltage VIH1,2,3 (A2,SCL,SDA,WP) www.rohm.com © 2010 ROHM Co., Ltd. All rights reserved. 0 1 2 3 4 5 6 Vcc[V] Fig.5 L input voltage VIL1,2,3 (A2,SCL,SDA,WP) 4/18 0 1 2 3 4 5 6 IOL2[mA] Fig.6 L output voltage VOL2-IOL2 (VCC=1.7V) 2010.09 - Rev.A Technical Note BU9844GUL-W 1.2 1 1.2 1 0.8 SPEC SPEC 1 SPEC 0.4 Ta=25℃ Ta=85℃ 0.8 ILO[μA] ILI[μA] VOL1[V] 0.8 0.6 0.6 0.4 0.6 0.4 Ta=85℃ Ta=85℃ 0.2 Ta=25℃ 0.2 0 0 1 2 3 4 5 6 0 0 1 2 3 4 5 6 0 Fig.8 Input leak current ILI(A2,SCL, WP) Fig.7 L input voltage VOL1-IOL1 (Vcc=2.5V) 0.5 fSCL=400kHz DATA=AAh ICC2[mA] 1 4 Ta=25℃ 0.3 Ta=85℃ Ta=-40℃ 6 SPEC 2 1.5 1 0.2 0.5 5 fSCL=400kHz DATA=AAh 0.4 Ta=25℃ Ta=85℃ 3 Vcc[V] 2.5 SPEC ISB[μA] SPEC 1.5 2 Fig.9 Output leak current ILO (SDA) 0.6 2.5 2 1 Vcc[V] IOL1[mA] ICC1[mA] Ta=-40℃ Ta=-40℃ Ta=-40℃ 0 Ta=25℃ 0.2 Ta=85℃ 0.1 0.5 Ta=-40℃ Ta=25℃ Ta=-40℃ 0 0 0 1 2 3 4 5 0 0 6 1 2 3 4 5 6 0 1 2 3 Vcc[V] Vcc[V] Fig.10 Consumption current at write action Icc1 (fSCL=400kHz) 5 6 Vcc[V] Fig.11 Consumption current at write action Icc2 (fSCL=400kHz) 10000 4 Fig.12 Standby current ISB 1.6 1 Ta=-40℃ Ta=25℃ 0.8 SPEC 0.6 tHIGH [μs] fSCL[kHz] SPEC 100 SPEC 1.2 Ta=85℃ tLOW[μs] 1000 Ta=85℃ 0.4 0.8 Ta=85℃ Ta=25℃ Ta=-40℃ Ta=25℃ 10 0.4 0.2 Ta=-40℃ 1 0 0 0 1 2 3 4 5 6 0 1 2 Vcc[V] Fig.13 SCL frequency fSCL 5 0 6 Ta=25℃ 0.2 Ta=85℃ 0.2 3 4 5 6 Ta=25℃ Ta=-40℃ -200 0 1 2 Vcc[V] 3 4 5 0 6 1 2 1 SPEC 4 5 6 Fig.18 Input data hold time tHD:DAT Fig.17 Start condition setup time tSU:STA 200 3 Vcc[V] Vcc[V] Fig.16 Start condition hold time tHD:STA 100 Ta=85℃ -150 Ta=-40℃ -0.2 2 6 -50 -100 Ta=25 ℃ 0 0 5 SPEC 0.4 Ta=-40℃ 4 0 SPEC tHD:DAT(HIGH)[ns] Ta=85℃ 0.4 1 3 50 0.6 tHD:DAT(HIGH)[ns] SPEC 0 2 Fig.15 Data clock “L” time tLOW 0.8 0.6 1 Vcc[V] 1 0.8 1 SPEC 0.8 SPEC 0.8 Ta=-40℃ Ta=85℃ 0 tPD0 [μs] Ta=85 ℃ Ta=25℃ 0.6 tPD1 [μs] tHD:STA[μs] 4 Fig.14 Data clock “H” time tHIGH 1 tSU:DAT(HIGH)[ns] 3 Vcc[V] Ta=25℃ 0.4 Ta=85℃ 0.6 Ta=25℃ 0.4 Ta=-40℃ -100 Ta=-40℃ 0.2 0.2 SPEC SPEC -200 0 0 1 2 3 4 5 6 Vcc[V] Fig.19 Input data setup time tSU:DAT www.rohm.com © 2010 ROHM Co., Ltd. All rights reserved. 0 0 1 2 3 4 Vcc[V] 5 6 Fig.20 Output data delay time tPD0 5/18 0 1 2 3 4 5 6 Vcc[V] Fig.21 Output data delay time tPD1 2010.09 - Rev.A Technical Note BU9844GUL-W 4 1 Ta=85℃ 4 3 0.6 Ta=-40℃ 0.4 2 Ta=85℃ 2 3 4 5 6 0 1 3 0 4 tWR[ms] 2 Ta=25℃ SPEC Ta=-40℃ 3 Ta=25℃ Ta=85℃ 2 0 5 6 1 2 3 0.6 0.5 0.5 Ta=-40℃ Ta=25℃ 0.2 Ta=85℃ SPEC 0.1 5 2 Ta=25℃ 0.3 Ta=85℃ 0.2 3 4 5 6 SPEC 0 1 2 4 5 6 Fig.27 Noise removal time tI (SCL H) 0.6 Ta=-40℃ 0.4 0.3 Ta=25℃ Ta=85℃ 0.2 SPEC 0.1 1 2 3 4 5 6 Vcc[V] Fig.28 Noise removal time tI (SCL L) 3 0 0 Vcc[V] Ta=85℃ SPEC Vcc[V] 0 1 0.2 0.5 0.1 0 0 Ta=25℃ Ta=-40℃ 6 Ta=-40℃ 0.4 tI(SDA H) [μs] 0.4 0.3 4 Fig.26 Internal write cycle time tWR 0.6 6 0.3 Vcc[V] Vcc[V] Fig.25 Bus release time before transfer start tBUF 5 0 0 tI(SDA L) [μs] 4 4 0.4 0.1 0 3 3 0.6 1 2 2 Fig.24 Stop condition setup time tSU:STO Ta=85℃ 1 1 1 0.5 3 Ta=-40℃ Ta=-40℃ Vcc[V] SPEC 5 4 tBUF[μs] 6 6 5 tI(SCL L) [μs] 5 Fig.23 Output data hold time tDH1 Fig.22 Output data hold time tDH1 Fig.29 Noise removal time tI (SDA H) 0 1 2 3 4 5 6 Vcc[V] Fig.30 Noise removal time tI (SDA L) 1.2 0.2 1 SPEC SPEC -0.2 tHIGH:WP[μs] 0 tSU:WP[μs] 4 Vcc[V] Vcc[V] 0 SPEC 0 2 tI(SCL H) [μs] 1 Ta=85℃ Ta=25℃ SPEC 0 0 2 1 Ta=-40℃ SPEC 0 3 Ta=25℃ 1 0.2 tSU:STO[μs] Ta=25℃ tDH1[μs] tDH0[μs] 0.8 5 Ta=85℃ -0.4 0.8 0.6 Ta=-40℃ 0.4 Ta=25℃ Ta=25℃ Ta=-40℃ 0.2 -0.6 Ta=85℃ 0 0 1 2 3 4 5 6 Vcc[V] Fig.31 WP setup time tSU:WP www.rohm.com © 2010 ROHM Co., Ltd. All rights reserved. 0 1 2 3 4 5 6 Vcc[V] Fig.32 WP valid time tHIGH: WP 6/18 2010.09 - Rev.A Technical Note BU9844GUL-W ●I2C BUS communication 2 ○I C BUS data communication 2 I C BUS data communication starts by start condition input, and ends by stop condition input. Data is always 8bit long, and acknowledge is always required after each byte. I2C BUS carries out data transmission with plural devices connected by 2 communication lines of serial data (SDA) and serial clock (SCL). Among devices, there are “master” that generates clock and control communication start and end, and “slave” that is controlled by addresses peculiar to devices. EEPROM becomes “slave”. And the device that outputs data to bys during data communication is called “transmitter”, and the device that receives data is called “receiver “. SDA 1-7 SCL S START ADDRESS condition 8 9 R/W ACK 1-7 8 DATA 9 ACK 1-7 DATA 8 9 ACK P STOP condition Fig.33 Data transfer timing ○Start condition (start bit recognition) ・Before executing each command, start condition (start bit) where SDA goes from “HIGH” down to “LOW” when SCL is “HIGH” is necessary. ・This IC always detects whether SDA and SCL are in start condition (start bit) of not, therefore, unless this condition is satisfied, any command is executed. ○Stop condition (stop bit recognition) ・Each command can be ended by SDA rising from “LOW” to “HIGH” when stop condition (stop bit), namely, SCL is “HIGH”. ○Acknowledge (ACK) signal ・This acknowledge (ACK) signal is a software rule to show whether data transfer has been made normally or not. In master and slave, the device (μ-COM at slave address input of write command, read command, and this IC at data output of read command) at the transmitter (sending) side releases the bus after output of 8bit data. ・This device (this IC at slave address input of write command , read command , and μ-COM at data output of read command) at the receiver (receiving) side sets SDA “LOW” during 9 clock cycles, and outputs acknowledge signal (ACK signal) showing that it has received the 8bit data. ・This IC, after recognizing start condition and slave address (8bit), outputs acknowledge signal (ACK signal) “LOW”. ・Each write action outputs acknowledge signal (ACK signal) “LOW”, at receiving 8bit data (word address and write data). ・Each read action outputs 8bit data (read data), and detects acknowledge signal (ACK signal) “LOW”. ・When acknowledge signal (ACK signal) is detected, and stop condition is not sent from the master (μ-COM) side, this IC continues data output. When acknowledge signal (ACK signal) is not detected, this IC stops data transfer, and recognizes stop condition (stop bit), and ends read action. And this IC gets in standby status. ○Device addressing ・Output slave address after start condition from master. ・The significant 4 bits of slave address are used for recognizing a device type. The device code of this IC is fixed to “1010”. ・Next slave addressed (A2 --- device address) are for selecting devices, and plural ones can be used on a same bus according to the number of device addresses. ・The most insignificant bit ( R / W --- READ / WRITE ) of slave address is used for designating write or read action, and is as shown below. Setting R / W to 0 --- write (setting 0 to word address setting of random read) Setting R / W to 1 --- read Type BU9844GUL-W Maximum number of connected buses Slave address 1 0 1 0 A2 0 PS R / W 2 PS is page select bits. www.rohm.com © 2010 ROHM Co., Ltd. All rights reserved. 7/18 2010.09 - Rev.A Technical Note BU9844GUL-W ●Command ○Write cycle ・Arbitrary data is written to EEPROM. When to write only 1 byte, byte write is normally used, and when to write continuous data of 2 bytes or more, simultaneous write is possible by page write cycle. S T A R T SDA LINE W R I T E SLAVE ADDRESS WORD ADDRESS WA 0 WA 7 1 0 1 0 P2 P1 P0 S T O P DATA R A / C W K D7 D0 A C K A C K WP Fig.34 Byte write cycle S T A R T SDA LINE SLAVE ADDRESS W R I T E WORD ADDRESS(n) WA 7 1 0 1 0 P2 P1 P0 R A / C W K WA 0 D7 S T O P DATA(n+15) DATA(n) D0 D0 A C K A C K A C K WP Fig.35 Page write cycle ・Data is written to the address designated by word address (n-th address). ・By issuing stop bit after 8bit data input, write to memory cell inside starts. ・When internal write is started, command is not accepted for tWR (5ms at maximum). ・By page write cycle, the following can be written in bulk. Up to 16 bytes. And when data of the maximum bytes or higher is sent, data from the first byte is overwritten. (Refer to “Internal address increment” of “Notes on page write cycle” in P8/16.) ・As for page write cycle of BU9844GUL-W, after page select bit (PS) of slave address is designated arbitrarily, by continuing data input of 2 bytes or more, the address of insignificant 4 bits is incremented internally, and data up to 16 bytes can be written. Note) 1 0 1 0 P2 P1 P0 Fig.36 Difference of slave address of each type www.rohm.com © 2010 ROHM Co., Ltd. All rights reserved. 8/18 2010.09 - Rev.A Technical Note BU9844GUL-W ○Notes on write cycle continuous input S T A R T SDA LINE W R I T E SLAVE ADDRESS At STOP (stop bit), Write starts. WORD ADDRESS(n) WA 0 WA 7 1 0 1 0 P2P1P0 DATA(n) R A / C WK D7 DATA(n+15) D0 D0 A C K A C K S T A R T S T O P 1 0 1 0 A C K Next command tWR (maximum : 5ms) Command is not accepted for this period. Fig.37 Page write cycle Note) 1 0 1 0 P2 P1 P0 Fig.38 Difference of each type of slave address ○Internal address increment Page write mode ○Notes on page write cycle List of numbers of page write Number of Pages 16Byte The above numbers are maximum bytes for respective types. Any types below these can be written. 1page = 16 bytes, but the page write cycle write time is 5ms at maximum for 16byte bulk write. It does not stand 5ms at maximum x 16 bytes = 80ms (Max.). WA3 0 0 0 WA2 0 0 0 0Eh 0 0 0 ------------- WA1 0 0 0 WA0 0 0 0 Increment --------- BU9844GUL-W WA4 0 0 0 --------- Product number WA7 ----0 ----0 ----0 ----- 0 0 0 1 1 0 1 1 0 1 1 0 0 1 0 Significant bit is fixed. No digit up For example, when it is started from address 0Eh, therefore, increment is made as below, 0Eh→0Fh→00h→01h ---, which please note. *0Eh --- 0E in hexadecimal, therefore, 00001110 becomes a binary number. ○Write protect terminal (WP) ・Write protect function When WP terminal is set Vcc (H level), data rewrite of all addresses is prohibited. When it is set GND (L level), data rewrite of all addresses is enabled. Be sure to connect this terminal to Vcc or GND, or control it to H level or L level. Do not use it open. At extremely low voltage at power ON/OFF, by setting the WP terminal “H”, mistake write can be prevented. During tWR, set the WP terminal always to “L”. If it is set “H”, write is forcibly terminated. www.rohm.com © 2010 ROHM Co., Ltd. All rights reserved. 9/18 2010.09 - Rev.A Technical Note BU9844GUL-W ●Command ○Read cycle Data of EEPROM is read. In read cycle, there are random read cycle and current read cycle. Random read cycle is a command to read data by designating address, and is used generally. Current read cycle is a command to read data of internal address register without designating address, and is used when to verify just after write cycle. In both the read cycles, sequential read cycle is available, and the next address data next address data can be read in succession. S T A R T SDA LINE W R I T E SLAVE ADDRESS WORD ADDRESS(n) WA 0 WA 7 1 0 1 0 P2 P1 P0 S T A R T R A / C W K R E A D SLAVE ADDRESS S T O P DATA(n) 1 0 1 0 A2 0 0 D7 A C K R A / C W K A C K It is necessary to input “H” to the last ACK. D0 Fig.39 Random Read cycle S T A R T SDA LINE R E A D SLA VE ADDRES S 1 0 1 0 P2 P1 P0 D7 R / W S T O P DATA It is necessary to input “H” to the last ACK. D0 A C K A C K Fig.40 Current read cycle S T A R T SDA LINE R E A D SLAVE ADDRESS 1 0 1 0 P2 P1 P0 DATA(n) D7 DATA(n+x) D0 R A / C W K S T O P D7 A C K A C K D0 A C K Fig.41 Sequential read cycle ・In random read cycle, data of designated word address can be read. ・When the command just before current read cycle is random read cycle, current read cycle (each including sequential read cycle), data of incremented last read address (n-th) address, i.e., data of the (n+1)-th address is output. ・When ACK signal “LOW” after D0 is detected, and stop condition is not sent from the master (μ-COM) side, the next address data can be read in succession. ・Read cycle is ended by stop condition where “H” is input to ACK signal after D0 and SDA signal is started at SCL signal “H”. ・When “H” is not input to ACK signal after D0, sequential read gets in, and the next data is output. Therefore, read command cycle cannot be ended. When to end read command cycle, be sure input stop condition to input “H” to ACK signal after D0, and to start SDA at SCL signal “H”. ・Sequential read is ended by stop condition where “H” is input to ACK signal after arbitrary D0 and SDA is started at SCL signal “H”. Note) 1 0 1 0 P2 P1 P0 Fig.42 Difference of slave address of each type www.rohm.com © 2010 ROHM Co., Ltd. All rights reserved. 10/18 2010.09 - Rev.A Technical Note BU9844GUL-W ●Software reset Software reset is executed when to avoid malfunction after power on, and to reset during command input. Software reset has several kinds, and 3 kinds of them are shown in the figure below. (Refer to Fig.43(a), Fig.43(b) and Fig.43(c).) In dummy clock input area, release the SDA bus (“H” by pull up). In dummy clock area, ACK output and read data “0” (both “L” level) may be output from EEPROM, therefore, if “H” is input forcibly, output may conflict and over current may flow, leading to instantaneous power failure of system power source or influence upon devices. Dummy clock x14 SCL 1 2 Start x2 13 Normal command 14 SDA Normal command Fig.43-(a) The case of dummy clock + START + START + command input SCL Start Dummy clock x9 Start 1 2 8 9 Normal command SDA Normal command Fig.43-(b) The case of START + 9 dummy clocks + START + command input Start x 9 SCL 1 2 7 3 8 9 Normal command SDA Normal command Fig.43-(c) START x 9 + command input * Start normal command from START input. ●Acknowledge polling During internal write execution, all input commands are ignored, therefore ACK is not sent back. During internal automatic write execution after write cycle input, next command (slave address) is sent, and if the first ACK signal sends back “L”, then it means end of write action, while if it sends back “H”, it means now in writing. By use of acknowledge polling, next command can be executed without waiting for tWR=5ms. When to write continuously, R / W = 0, when to carry out current read cycle after write, slave address R / W = 1 is sent, and if ACK signal sends back “L”, then execute word address input and data output and so forth. During internal write, First write command S T A R T Write command ACK = HIGH is sent back. S T O P S T A R T S Slave T A address R T A C address K H Slave … A C K H tWR Second write command … S T A R T A C address K H Slave S T Slave A R address T A C K L Word address A C K L Data A C K L S T O P tWR After completion of internal write, ACK = LOW is sent back, so input next word address and data in succession. Fig.44 Case to continuously write by acknowledge polling www.rohm.com © 2010 ROHM Co., Ltd. All rights reserved. 11/18 2010.09 - Rev.A Technical Note BU9844GUL-W ●WP valid timing (write cancel) WP is usually to “H” or “L”, but when WP is used to cancel write cycle and so forth, pay attention to the following WP valid timing. During write cycle execution, in cancel valid area, by setting WP = “H”, write cycle can be cancelled. In both byte write cycle and page write cycle, the area from the first start condition of command to the rise of clock to taken in D0 of data (in page write cycle, the first byte data) is cancel invalid area. WP input in this area becomes don’t care. Set the setup time to rise of D0 taken SCL 100ns or more. The area from the rise of SCL to take in D0 to the end of internal automatic write (tWR) is cancel valid area. And, when it is set WP = “H” during tWR, write is ended forcibly, data of address under access is not guaranteed, therefore, write it once again. (Refer to Fig.45.) After execution of forced end by WP, standby status gets in, so there is no need to wait for tWR (5ms at maximum). ·Rise of D0 taken clock SCL SCL ·Rise of SDA SDA D1 D0 SDA ACK Enlarged view SDA S A A T Slave C Word C D7 D6 D5 D4 D3 D2 D1 D0 A K K R address L address L T WP cancel invalid area A C K L D0 ACK Enlarged view Data A C K L S T O P tWR WP cancel valid area Write forced end Data is not written Data not guaranteed WP Fig. 45 WP valid timing ●Command cancel by start condition and stop condition During command input, by continuously inputting start condition and stop condition, command can be cancelled. (Refer to fig.46) However, in ACK output area and during data read, SDA bus may output “L”, and in this case, start condition and stop condition cannot be input, so reset is not available. Therefore, execute software reset. and when command is cancelled by start, stop condition, during random read cycle, sequential read cycle, or current read cycle, internal setting address is not determined, therefore, it is not possible to carry out current read cycle in succession. When to carry out read cycle in succession, carry out random read cycle. SCL SDA 1 0 1 0 Start condition Stop condition Fig. 46 Case of cancel by start, stop condition during slave address input www.rohm.com © 2010 ROHM Co., Ltd. All rights reserved. 12/18 2010.09 - Rev.A Technical Note BU9844GUL-W ●I/O peripheral circuit ○Pull up resistance of SDA terminal SDA is NMOS open drain, so requires pull up resistance. As for this resistance value (RPU), select an appropriate value to this resistance value from microcontroller VIL, IL, and VOL-IOL characteristics of this IC. If RPU is large, action frequency is limited. The smaller the RPU, the larger the consumption current at action. ○Maximum value of RPU The maximum value of RPU is determined by the following factors. (1) SDA rise time to be determined by the capacity (CBUS) of bus line of RPU and SDA should be tR or below. And AC timing should be satisfied even when SDA rise time is late. A to be determined by input leak total (IL) of device connected to bus at output of “H” to (2) The bus electric potential ○ SDA bus and RPU should sufficiently secure the input “H” level (VIH) of microcontroller and EEPROM including recommended noise margin 0.2Vcc. VCC-ILRPU-0.2 VCC ≥ VIH ∴ RPU ≦ 0.8VCC-VIH IL RPU 300 SDA terminal A Ex.) When VCC =3V, IL=10μA, VIH=0.7 Vcc from (2) 0.8×3-0.7×3 ≦ RPU 10×10-6 ≦ BU9844GUL-W Microcontroller IL IL Bus line capacity CBUS ［kΩ］ Fig.47 I/O circuit diagram ○Minimum value of RPU The minimum value of RPU is determined by the following factors. (1) When IC outputs LOW, it should be satisfied that VOLMAX = 0.4V and IOLMAX = 3mA. VCC-VOL VCC-VOL ∴ RPU ≧ ≦ IOL RPU IOL (2) VOLMAX = 0.4V should secure the input “L” level (VIL) of microcontroller and EEPROM including recommended noise margin 0.1VCC. VOLMAX ≤ VIL – 0.1VCC Ex.) When VCC = 3V, VOL = 0.4V, IOL = 3mA, microcontroller, EEPROM VIL = 0.3VCC From (1), RPU ≧ 3-0.4 -3 3×10 ≧ 867 And ［Ω］ VOL VIL =0.4 ［V］ =0.3×3 =0.9 ［V］ Therefore, the condition (2) is satisfied. ○Pull up resistance of SCL terminal When SCL control is made at CMOS output port, there is no need, but in the case there is timing where SCL becomes “Hi-Z”, add a pull up resistance. As for the pull up resistance, one of several kΩ ~ several ten kΩ is recommended in consideration of drive performance of output port of microcontroller. ●A2, WP process ○Process of device address terminals (A2) Check whether the set device address coincides with device address input sent from the master side or not, and select one among plural devices connected to a same bus. Connect this terminal to pull up of pull down, or VCC or GND. ○Process of WP terminal WP terminal is the terminal that prohibits and permits write in hardware manner. In “H” status, only READ is available and WRITE of all addresses is prohibited. In the case of “L”, both are available. In the case to use it as an ROM, it is recommended to connect it to pull up or VCC. In the case to use both READ and WRITE, control WP terminal or connect it to pull down or GND. www.rohm.com © 2010 ROHM Co., Ltd. All rights reserved. 13/18 2010.09 - Rev.A Technical Note BU9844GUL-W ●Cautions on microcontroller connection ○Rs 2 In I C BUS, it is recommended that SDA port is of open drain input / output. However, when to use COMS input / output of tri state to SDA port, insert a series resistance Rs between the pull up resistance RPU and the SDA terminal of EEPROM. This controls over protection of SDA terminal against surge. Therefore, even when SDA port is open drain input / output, Rs can be used. ACK SCL RPU RS Microcontroller SDA “H” output of microcontroller “L” output of EEPROM Over current flows to SDA line by “H” output of microcontroller and “L” output of EEPROM. EEPROM Fig.49 Input / output collision timing Fig.48 I/O circuit diagram ○Maximum value of Rs The maximum value of Rs is determined by the following relations. (1) SDA rise time to be determined by the capacity (CBUS) of bus line of RPU and SDA should be tR or below. And AC timing should be satisfied even when SDA rise time is late. (2) The bus electric potential A to be determined by RPU and Rs at the moment when EEPROM outputs “L” to SDA bus should sufficiently secure the input “L” level (VIL) of microcontroller including recommended noise margin 0.1VCC. (VCC-VOL)×RS RPU+RS VCC RPU A RS ∴ VOL IOL ≦ VOL+0.1VCC≦VIL VIL-VOL-0.1VCC 1.1VCC-VIL × RPU Example) When VCC=3V, VIL=0.3VCC, VOL=0.4V, RPU=20kΩ, Bus line capacity CBUS From(2) VIL RS + RS ≦ 0.3×3-0.4-0.1×3 1.1×3-0.3×3 × 20×103 EEPROM Microcontroller ≦ 1.67［kΩ］ Fig.50 I/O circuit diagram ○Minimum value of Rs The minimum value of Rs is determined by over current at bus collision. When over current flows, noises in power source line, and instantaneous power failure of power source may occur. When allowable over current is defined as I, the following relation must be satisfied. Determine the allowable current in consideration of impedance of power source line in set and so forth. Set the over current to EEPROM 10mA or below. VCC ≦ I RS RPU RS "L" output ∴ RS ≧ VCC I Example) When Vcc =3V, I = 10mA Over current I "H" output RS Microcontroller www.rohm.com 3 -3 10×10 EEPROM ≧ 300［Ω］ Fig.51 I/O Circuit diagram © 2010 ROHM Co., Ltd. All rights reserved. ≧ 14/18 2010.09 - Rev.A Technical Note BU9844GUL-W ●I2C BUS input / output circuit ○Input (A2,SCL) Fig.52 Input pin circuit diagram ○Input / output (SDA) Fig.53 Input / output pin circuit diagram ○Input (WP) Fig.54 Input pin circuit diagram www.rohm.com © 2010 ROHM Co., Ltd. All rights reserved. 15/18 2010.09 - Rev.A Technical Note BU9844GUL-W ●Notes on power ON At power on, in IC internal circuit and set, Vcc rises through unstable low voltage area, and IC inside is not completely reset, and malfunction may occur. To prevent this, function of POR circuit and LVCC circuit are equipped. To assure the action, observe the following conditions at power on. 1. Set SDA= “H” and SCL = “L” or “H”. 2. Start power source so as to satisfy the recommended conditions of tR, tOFF, and Vbot for operating POR circuit. tR VCC Recommended conditons of tR, tOFF, Vbot tOFF Vbot 0 tR tOFF Vbot 10ms or below 10ms or higher 0.3V or below 100ms or below 10ms or higher 0.2V or below Fig. 55 Rise waveform diagram 3. Set SDA and SCL so as not to become “Hi-Z”. When the above conditions 1 and 2 cannot be observed, take the following countermeasures. a) In the case when the above condition 1 cannot be observed. When SDA becomes “L” at power on. → Control SCL and SDA as shown below, to make SCL and, “H” and “H”. V CC tLOW SCL SDA After Vcc becomes stable After Vcc becomes stable tDH tSU:DAT Fig.56 When SCL =”H” and SDA = “L” tSU:DAT Fig.57 When SCL = “H” and SDA = “L” b) In the case when the above condition 2 cannot be observed. → After power source becomes stable, execute software reset (P10). c) In the case when the above conditions 1 and 2 cannot be observed. → Carry out a), and then carry out b). ●Low voltage malfunction prevention function LVCC circuit prevents data rewrite action at low power, and prevents wrong write. At LVCC voltage (Typ. = 1.2V) or below, it prevent data rewrite. ●Vcc noise countermeasures ○Bypass capacitor When noise or surge gets in the power source line, malfunction may occur, therefore, for removing tese, it is recommended to attach a by pass capacitor (0.1μF) between IC Vcc and GND. At that moment , attach it as close to IC as possible. And, it is also recommended to attach a bypass capacitor between board Vcc and GND. www.rohm.com © 2010 ROHM Co., Ltd. All rights reserved. 16/18 2010.09 - Rev.A Technical Note BU9844GUL-W ●Notes for use (1) Described numeric values and data are design representative values, and the values are not guaranteed. (2) We believe that application circuit examples are recommendable, however, in actual use, confirm characteristics further sufficiently. In the case of use by changing the fixed number of external parts, make your decision with sufficient margin in consideration of static characteristics and transition characteristics and fluctuations of external parts and our LSI. (3) Absolute maximum ratings If the absolute maximum ratings such as impressed voltage and action temperature range and so forth are exceeded, LSI may be destructed. Do not impress voltage and temperature exceeding the absolute maximum ratings. In the case of fear exceeding the absolute maximum ratings, take physical safety countermeasures such as fuses, and see to it that conditions exceeding the absolute maximum ratings should not be impressed to LSI. (4) GND electric potential Set the voltage of GND terminal lowest at any action condition. Make sure that each terminal voltage is lower than that of GND terminal. (5) Thermal design In considereation of permissible loss in actual use condition, carry out heat design with sufficient margin. (6) Terminal to terminal shortcircuit and wrong packaging When to package LSI onto a board, pay sufficient attention to LSI direction and displacement. Wrong packaging may destruct LSI. And in the case of shortcircuit between LSI terminals and terminals and power source, terminal and GND owing to foreign matter, LSI may be destructed. (7) Use in a strong electromagnetic field may cause malfunction, therefore, evaluate design sufficiently. www.rohm.com © 2010 ROHM Co., Ltd. All rights reserved. 17/18 2010.09 - Rev.A Technical Note BU9844GUL-W ●Ordering part number B U Part No. 9 8 4 4 Part No. G U L Package GUL : VCSP50L1 - W W-CELL E 2 Packaging and forming specification E2: Embossed tape and reel VCSP50L1(BU9844GUL-W) <Tape and Reel information> 0.1±0.05 1.60±0.1 0.55MAX 1.84±0.1 1PIN MARK Tape Embossed carrier tape Quantity 3000pcs Direction of feed E2 The direction is the 1pin of product is at the upper left when you hold ( reel on the left hand and you pull out the tape on the right hand ) S A C B B A 1 0.55±0.1 P=0.5×2 (φ0.15)INDEX POST 0.42±0.1 0.06 S 6-φ0.25±0.05 0.05 A B 2 1pin 0.5 (Unit : mm) www.rohm.com © 2010 ROHM Co., Ltd. All rights reserved. Reel 18/18 Direction of feed ∗ Order quantity needs to be multiple of the minimum quantity. 2010.09 - Rev.A Notice Notes No copying or reproduction of this document, in part or in whole, is permitted without the consent of ROHM Co.,Ltd. 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