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| 24LC32A 32K 2.5V I2CTM Serial EEPROM FEATURES * Single supply with operation down to 2.5V - Maximum write current 3 mA at 6.0V - Standby current 1 A max at 2.5V * 2-wire serial interface bus, I2CTM compatible * 100 kHz (2.5V) and 400 kHz (5V) compatibility * Self-timed ERASE and WRITE cycles * Power on/off data protection circuitry * Hardware write protect * 1,000,000 Erase/Write cycles guaranteed * 32 byte page or byte write modes available * Schmitt trigger filtered inputs for noise suppression * Output slope control to eliminate ground bounce * 2 ms typical write cycle time, byte or page * Up to eight devices may be connected to the same bus for up to 256K bits total memory * Electrostatic discharge protection > 4000V * Data retention > 200 years * 8-pin PDIP and SOIC packages * Temperature ranges - Commercial (C): 0C to +75C - Industrial (I): +40C to +85C PACKAGE TYPES PDIP A0 A1 A2 Vss 1 24LC32A 2 3 4 8 7 6 5 Vcc WP SCL SDA SOIC A0 A1 A2 Vss 1 24LC32A 2 3 4 8 7 6 5 Vcc WP SCL SDA DESCRIPTION The Microchip Technology Inc. 24LC32A is a 4K x 8 (32K bit) Serial Electrically Erasable PROM capable of operation across a broad voltage range (2.5V to 6.0V). It has been developed for advanced, low power applications such as personal communications or data acquisition. The 24LC32A also has a page-write capability of up to 32 bytes of data. The 24LC32A is capable of both random and sequential reads up to the 32K boundary. Functional address lines allow up to eight 24LC32A devices on the same bus, for up to 256K bits address space. Advanced CMOS technology and broad voltage range make this device ideal for low-power/low-voltage, nonvolatile code and data applications. The 24LC32A is available in the standard 8-pin plastic DIP and both 150 mil and 200 mil SOIC packaging. BLOCK DIAGRAM A0..A2 WP WP HV GENERATOR I/O CONTROL LOGIC MEMORY CONTROL LOGIC XDEC EEPROM ARRAY PAGE LATCHES I/O SCL YDEC SDA VCC VSS SENSE AMP R/W CONTROL I2C is a trakemark of Philips Corporation. (c) 1996 Microchip Technology Inc. Preliminary This document was created with FrameMaker 4 0 4 DS21144B-page 1 24LC32A 1.0 1.1 ELECTRICAL CHARACTERISTICS Maximum Ratings* TABLE 1-1: Name A0..A2 VSS SDA SCL WP VCC PIN FUNCTION TABLE Function User Configurable Chip Selects Ground Serial Address/Data I/O Serial Clock Write Protect Input +2.5V to 6.0V Power Supply VCC...................................................................................7.0V All inputs and outputs w.r.t. VSS ............... -0.6V to VCC +1.0V Storage temperature .....................................-65C to +150C Ambient temp. with power applied ................-65C to +125C Soldering temperature of leads (10 seconds) ............. +300C ESD protection on all pins .................................................. 4 kV *Notice: Stresses above those listed under "Maximum Ratings" may cause permanent damage to the device. This is a stress rating only and functional operation of the device at those or any other conditions above those indicated in the operational listings of this specification is not implied. Exposure to maximum rating conditions for extended periods may affect device reliability. TABLE 1-2: DC CHARACTERISTICS Vcc = +2.5V to 6.0V Commercial (C): Tamb = 0C to +70C Industrial (I): Tamb = -40C to +85C Parameter A0, A1, A2, SCL , SDA and WP pins: High level input voltage Low level input voltage Hysteresis of Schmitt Trigger inputs Low level output voltage Input leakage current Output leakage current Pin capacitance (all inputs/outputs) Operating current Symbol Min Typ Max Units Conditions VIH VIL VHYS VOL ILI ILO CIN,COUT .7 VCC -- .05 VCC -- -10 -10 -- -- .3 Vcc -- .40 10 10 10 V V V V A A pF mA mA A A (Note) IOL = 3.0 mA VIN = .1V to VCC VOUT = .1V to VCC VCC = 5.0V (Note) Tamb = 25C, Fc = 1 MHz VCC = 6.0V VCC = 6.0V, SCL = 400 KHz SCL = SDA = VCC = 5.5V VCC = 2.5V (Note) -- 3 ICC Write ICC Read -- 0.5 Standby current ICCS -- 1 5 ICCS 1 Note: This parameter is periodically sampled and not 100% tested. FIGURE 1-1: BUS TIMING START/STOP VHYS SCL TSU:STA SDA THD:STA TSU:STO START STOP DS21144B-page 2 Preliminary (c) 1996 Microchip Technology Inc. 24LC32A TABLE 1-3: AC CHARACTERISTICS Vcc = 2.5-6.0V Standard Mode Min Clock frequency Clock high time Clock low time SDA and SCL rise time SDA and SCL fall time START condition hold time START condition setup time Data input hold time Data input setup time STOP condition setup time Output valid from clock Bus free time FCLK THIGH TLOW TR TF THD:STA TSU:STA THD:DAT TSU:DAT TSU:STO TAA TBUF -- 4000 4700 -- -- 4000 4700 0 250 4000 -- 4700 Max 100 -- -- 1000 300 -- -- -- -- -- 3500 -- Vcc = 4.5-6.0V Fast Mode Min -- 600 1300 -- -- 600 600 0 100 600 -- 1300 Max 400 -- -- 300 300 -- -- -- -- -- 900 -- kHz ns ns ns ns ns ns ns ns ns ns ns (Note 2) Time the bus must be free before a new transmission can start (Note 1), CB 100 pF (Note 3) Byte or Page mode 25C, Vcc = 5.0V, Block Mode Cycle (Note 4) (Note 1) (Note 1) After this period the first clock pulse is generated Only relevant for repeated START condition Parameter Symbol Units Remarks Output fall time from VIH min to VIL max Input filter spike suppression (SDA and SCL pins) Write cycle time Endurance TOF TSP TWR -- -- -- -- 1M 250 50 5 -- 20 +0.1CB -- -- 1M 250 50 5 -- ns ns ms cycles Note 1: Not 100% tested. CB = Total capacitance of one bus line in pF. 2: As a transmitter, the device must provide an internal minimum delay time to bridge the undefined region (minimum 300 ns) of the falling edge of SCL to avoid unintended generation of START or STOP conditions. 3: The combined TSP and VHYS specifications are due to Schmitt trigger inputs which provide improved noise and spike suppression. This eliminates the need for a Ti specification for standard operation. 4: This parameter is not tested but guaranteed by characterization. For endurance estimates in a specific application, please consult the Total Endurance Model which can be obtained on our BBS or website. FIGURE 1-2: BUS TIMING DATA TF THIGH TLOW TR SCL TSU:STA SDA IN THD:STA TSP TAA SDA OUT THD:STA THD:DAT TSU:DAT TSU:STO TAA TBUF (c) 1996 Microchip Technology Inc. Preliminary DS21144B-page 3 24LC32A 2.0 FUNCTIONAL DESCRIPTION 3.4 Data Valid (D) The 24LC32A supports a Bi-directional 2-wire bus and data transmission protocol. A device that sends data onto the bus is defined as transmitter, and a device receiving data as receiver. The bus must be controlled by a master device which generates the Serial Clock (SCL), controls the bus access, and generates the START and STOP conditions, while the 24LC32A works as slave. Both master and slave can operate as transmitter or receiver but the master device determines which mode is activated. The state of the data line represents valid data when, after a START condition, the data line is stable for the duration of the HIGH period of the clock signal. The data on the line must be changed during the LOW period of the clock signal. There is one clock pulse per bit of data. Each data transfer is initiated with a START condition and terminated with a STOP condition. The number of the data bytes transferred between the START and STOP conditions is determined by the master device. 3.0 BUS CHARACTERISTICS The following bus protocol has been defined: * Data transfer may be initiated only when the bus is not busy. * During data transfer, the data line must remain stable whenever the clock line is HIGH. Changes in the data line while the clock line is HIGH will be interpreted as a START or STOP condition. Accordingly, the following bus conditions have been defined (Figure 3-1). 3.5 Acknowledge Each receiving device, when addressed, is obliged to generate an acknowledge signal after the reception of each byte. The master device must generate an extra clock pulse which is associated with this acknowledge bit. Note: The 24LC32A does not generate any acknowledge bits if an internal programming cycle is in progress. 3.1 Bus not Busy (A) Both data and clock lines remain HIGH. 3.2 Start Data Transfer (B) A HIGH to LOW transition of the SDA line while the clock (SCL) is HIGH determines a START condition. All commands must be preceded by a START condition. 3.3 Stop Data Transfer (C) A device that acknowledges must pull down the SDA line during the acknowledge clock pulse in such a way that the SDA line is stable LOW during the HIGH period of the acknowledge related clock pulse. Of course, setup and hold times must be taken into account. During reads, a master must signal an end of data to the slave by NOT generating an acknowledge bit on the last byte that has been clocked out of the slave. In this case, the slave (24LC32A) will leave the data line HIGH to enable the master to generate the STOP condition. A LOW to HIGH transition of the SDA line while the clock (SCL) is HIGH determines a STOP condition. All operations must be ended with a STOP condition. FIGURE 3-1: (A) SCL (B) DATA TRANSFER SEQUENCE ON THE SERIAL BUS (D) (D) (C) (A) SDA START CONDITION ADDRESS OR DATA ACKNOWLEDGE ALLOWED VALID TO CHANGE STOP CONDITION DS21144B-page 4 Preliminary (c) 1996 Microchip Technology Inc. 24LC32A 3.6 Device Addressing A control byte is the first byte received following the start condition from the master device. The control byte consists of a 4-bit control code; for the 24LC32A this is set as 1010 binary for read and write (R/W) operations. The next three bits of the control byte are the device select bits (A2, A1, A0). They are used by the master device to select which of the eight devices are to be accessed. These bits are in effect the three most significant bits of the word address. The last bit of the control byte defines the operation to be performed. When set to a one a read operation is selected, and when set to a zero a write operation is selected. The next two bytes received define the address of the first data byte (Figure 3-3). Because only A11...A0 are used, the upper four address bits must be zeros. The most significant bit of the most significant byte of the address is transferred first. Following the start condition, the 24LC32A monitors the SDA bus checking the device type identifier being transmitted. Upon receiving a 1010 code and appropriate device select bits, the slave device outputs an acknowledge signal on the SDA line. Depending on the state of the R/W bit, the 24LC32A will select a read or write operation. Operation Read Write Control Code 1010 1010 Device Select Device Address Device Address R/W 1 0 FIGURE 3-2: CONTROL BYTE ALLOCATION READ/WRITE START SLAVE ADDRESS R/W A 1 0 1 0 A2 A1 A0 FIGURE 3-3: ADDRESS SEQUENCE BIT ASSIGNMENTS CONTROL BYTE A 2 A 1 A 0 R/W ADDRESS BYTE 1 A 11 A 10 A 9 A 8 A 7 ADDRESS BYTE 0 * * * * * * A 0 1 0 1 0 0 0 0 0 SLAVE ADDRESS DEVICE SELECT BUS (c) 1996 Microchip Technology Inc. Preliminary DS21144B-page 5 24LC32A 4.0 4.1 WRITE OPERATION Byte Write 4.2 Page Write Following the start condition from the master, the control code (four bits), the device select (three bits), and the R/W bit which is a logic low are clocked onto the bus by the master transmitter. This indicates to the addressed slave receiver that a byte with a word address will follow after it has generated an acknowledge bit during the ninth clock cycle. Therefore, the next byte transmitted by the master is the high-order byte of the word address and will be written into the address pointer of the 24LC32A. The next byte is the least significant address byte. After receiving another acknowledge signal from the 24LC32A the master device will transmit the data word to be written into the addressed memory location. The 24LC32A acknowledges again and the master generates a stop condition. This initiates the internal write cycle, and during this time the 24LC32A will not generate acknowledge signals (Figure 4-1). The write control byte, word address and the first data byte are transmitted to the 24LC32A in the same way as in a byte write. But instead of generating a stop condition, the master transmits up to 32 bytes which are temporarily stored in the on-chip page buffer and will be written into memory after the master has transmitted a stop condition. After receipt of each word, the five lower address pointer bits are internally incremented by one. If the master should transmit more than 32 bytes prior to generating the stop condition, the address counter will roll over and the previously received data will be overwritten. As with the byte write operation, once the stop condition is received, an internal write cycle will begin. (Figure 4-2). FIGURE 4-1: BYTE WRITE S T A R T BUS ACTIVITY MASTER SDA LINE BUS ACTIVITY CONTROL BYTE ADDRESS HIGH BYTE 0000 ADDRESS LOW BYTE DATA S T O P A C K A C K A C K A C K FIGURE 4-2: PAGE WRITE S T O P A C K S BUS ACTIVITY T A MASTER R T SDA LINE BUS ACTIVITY CONTROL BYTE ADDRESS HIGH BYTE 0000 ADDRESS LOW BYTE DATA BYTE 0 DATA BYTE 31 A C K A C K A C K DS21144B-page 6 Preliminary (c) 1996 Microchip Technology Inc. 24LC32A 5.0 ACKNOWLEDGE POLLING 6.0 READ OPERATION Since the device will not acknowledge during a write cycle, this can be used to determine when the cycle is complete (this feature can be used to maximize bus throughput). Once the stop condition for a write command has been issued from the master, the device initiates the internally timed write cycle. Acknowledge Polling (ACK) can be initiated immediately. This involves the master sending a start condition followed by the control byte for a write command (R/W = 0). If the device is still busy with the write cycle, then NO ACK will be returned. If the cycle is complete, then the device will return the ACK and the master can then proceed with the next read or write command. See Figure 5-1 for flow diagram. Read operations are initiated in the same way as write operations with the exception that the R/W bit of the slave address is set to one. There are three basic types of read operations: current address read, random read, and sequential read. 6.1 Current Address Read FIGURE 5-1: ACKNOWLEDGE POLLING FLOW Send Write Command The 24LC32A contains an address counter that maintains the address of the last word accessed, internally incremented by one. Therefore, if the previous access (either a read or write operation) was to address n (n is any legal address), the next current address read operation would access data from address n + 1. Upon receipt of the slave address with R/W bit set to one, the 24LC32A issues an acknowledge and transmits the eight bit data word. The master will not acknowledge the transfer but does generate a stop condition and the 24LC32A discontinues transmission (Figure 6-1). 6.2 Send Stop Condition to Initiate Write Cycle Random Read Send Start Send Control Byte with R/W = 0 Did Device Acknowledge (ACK = 0)? YES Next Operation NO Random read operations allow the master to access any memory location in a random manner. To perform this type of read operation, first the word address must be set. This is done by sending the word address to the 24LC32A as part of a write operation (R/W bit set to zero). After the word address is sent, the master generates a start condition following the acknowledge. This terminates the write operation, but not before the internal address pointer is set. Then the master issues the control byte again but with the R/W bit set to a one. The 24LC32A will then issue an acknowledge and transmit the 8-bit data word. The master will not acknowledge the transfer but does generate a stop condition which causes the 24LC32A to discontinue transmission (Figure 6-2). FIGURE 6-1: CURRENT ADDRESS READ BUS ACTIVITY MASTER S T A R T S A C K N O A C K S T O P P CONTROL BYTE DATA BYTE SDA LINE BUS ACTIVITY (c) 1996 Microchip Technology Inc. Preliminary DS21144B-page 7 24LC32A 6.3 Contiguous Addressing Across Multiple Devices 6.4 Sequential Read Sequential reads are initiated in the same way as a random read except that after the 24LC32A transmits the first data byte, the master issues an acknowledge as opposed to the stop condition used in a random read. This acknowledge directs the 24LC32A to transmit the next sequentially addressed 8-bit word (Figure 6-3). Following the final byte transmitted to the master, the master will NOT generate an acknowledge but will generate a stop condition. To provide sequential reads the 24LC32A contains an internal address pointer which is incremented by one at the completion of each operation. This address pointer allows the entire memory contents to be serially read during one operation. The internal address pointer will automatically roll over from address 0FFF to address 000 if the master acknowledges the byte received from the array address 0FFF. The device select bits A2, A1, A0 can be used to expand the contiguous address space for up to 256K bits by adding up to eight 24LC32A's on the same bus. In this case, software can use A0 of the control byte as address bit A12, A1 as address bit A13, and A2 as address bit A14. FIGURE 6-2: RANDOM READ S T ADDRESS A LOW BYTE R T S T BUS ACTIVITY A MASTER R T SDA LINE BUS ACTIVITY CONTROL BYTE ADDRESS HIGH BYTE 0000 CONTROL BYTE DATA BYTE S T O P N O A C K A C K A C K A C K A C K FIGURE 6-3: SEQUENTIAL READ S T O P N O A C K BUS ACTIVITY MASTER SDA LINE BUS ACTIVITY CONTROL BYTE DATA n DATA n + 1 DATA n + 2 DATA n + x A C K A C K A C K A C K DS21144B-page 8 Preliminary (c) 1996 Microchip Technology Inc. 24LC32A 7.0 7.1 PIN DESCRIPTIONS A0, A1, A2 Chip Address Inputs 8.0 NOISE PROTECTION The A0..A2 inputs are used by the 24LC32A for multiple device operation and conform to the 2-wire bus standard. The levels applied to these pins define the address block occupied by the device in the address map. A particular device is selected by transmitting the corresponding bits (A2, A1, A0) in the control byte (Figure 3-3). The SCL and SDA inputs have filter circuits which suppress noise spikes to ensure proper device operation even on a noisy bus. All I/O lines incorporate Schmitt triggers for 400 kHz (Fast Mode) compatibility. 9.0 POWER MANAGEMENT 7.2 SDA Serial Address/Data Input/Output This is a Bi-directional pin used to transfer addresses and data into and data out of the device. It is an open drain terminal, therefore the SDA bus requires a pullup resistor to VCC (typical 10K for 100 kHz, 1K for 400 kHz) For normal data transfer SDA is allowed to change only during SCL low. Changes during SCL HIGH are reserved for indicating the START and STOP conditions. This design incorporates a power standby mode when the device is not in use and automatically powers off after the normal termination of any operation when a stop bit is received and all internal functions are complete. This includes any error conditions, i.e., not receiving an acknowledge or stop condition per the 2-wire bus specification. The device also incorporates VDD monitor circuitry to prevent inadvertent writes (data corruption) during low-voltage conditions. The VDD monitor circuitry is powered off when the device is in standby mode in order to further reduce power consumption. 7.3 SCL Serial Clock This input is used to synchronize the data transfer from and to the device. 7.4 WP This pin must be connected to either VSS or VCC. If tied to VSS, normal memory operation is enabled (read/write the entire memory 000-FFF). If tied to VCC, WRITE operations are inhibited. The entire memory will be write-protected. Read operations are not affected. (c) 1996 Microchip Technology Inc. Preliminary DS21144B-page 9 24LC32A NOTES: DS21144B-page 10 Preliminary (c) 1996 Microchip Technology Inc. 24LC32A 24LC32A Product Identification System To order or to obtain information, e.g., on pricing or delivery, please use the listed part numbers, and refer to the factory or the listed sales offices. 24LC32A - /P Package: P = Plastic DIP (300 mil Body), 8-lead SN = Plastic SOIC (150 mil Body, EIAJ standard) SM = Plastic SOIC (207 mil Body, EIAJ standard) Temperature Range: Device: Blank = 0C to +70C I = -40C to +85C 24LC32A 24LC32AT 32K I2C Serial EEPROM (100 kHz, 400 kHz) 32K I2C Serial EEPROM (Tape and Reel) (c) 1996 Microchip Technology Inc. Preliminary DS21144B-page 11 WORLDWIDE SALES & SERVICE AMERICAS Corporate Office Microchip Technology Inc. 2355 West Chandler Blvd. Chandler, AZ 85224-6199 Tel: 602 786-7200 Fax: 602 786-7277 Technical Support: 602 786-7627 Web: http://www.microchip.com Atlanta Microchip Technology Inc. 500 Sugar Mill Road, Suite 200B Atlanta, GA 30350 Tel: 770 640-0034 Fax: 770 640-0307 Boston Microchip Technology Inc. 5 Mount Royal Avenue Marlborough, MA 01752 Tel: 508 480-9990 Fax: 508 480-8575 Chicago Microchip Technology Inc. 333 Pierce Road, Suite 180 Itasca, IL 60143 Tel: 708 285-0071 Fax: 708 285-0075 Dallas Microchip Technology Inc. 14651 Dallas Parkway, Suite 816 Dallas, TX 75240-8809 Tel: 972 991-7177 Fax: 972 991-8588 Dayton Microchip Technology Inc. Suite 150 Two Prestige Place Miamisburg, OH 45342 Tel: 513 291-1654 Fax: 513 291-9175 Los Angeles Microchip Technology Inc. 18201 Von Karman, Suite 1090 Irvine, CA 92612 Tel: 714 263-1888 Fax: 714 263-1338 New York Microchip Technmgy Inc. 150 Motor Parkway, Suite 416 Hauppauge, NY 11788 Tel: 516 273-5305 Fax: 516 273-5335 San Jose Microchip Technology Inc. 2107 North First Street, Suite 590 San Jose, CA 95131 Tel: 408 436-7950 Fax: 408 436-7955 Toronto Microchip Technology Inc. 5925 Airport Road, Suite 200 Mississauga, Ontario L4V 1W1, Canada Tel: 905 405-6279 Fax: 905 405-6253 ASIA/PACIFIC China Microchip Technology Unit 406 of Shanghai Golden Bridge Bldg. 2077 Yan'an Road West, Hongiao District Shanghai, Peoples Republic of China Tel: 86 21 6275 5700 Fax: 011 86 21 6275 5060 Hong Kong Microchip Technology RM 3801B, Tower Two Metroplaza 223 Hing Fong Road Kwai Fong, N.T. Hong Kong Tel: 852 2 401 1200 Fax: 852 2 401 3431 India Microchip Technology No. 6, Legacy, Convent Road Bangalore 560 025 India Tel: 91 80 526 3148 Fax: 91 80 559 9840 Korea Microchip Technology 168-1, Youngbo Bldg. 3 Floor Samsung-Dong, Kangnam-Ku, Seoul, Korea Tel: 82 2 554 7200 Fax: 82 2 558 5934 Singapore Microchip Technology 200 Middle Road #10-03 Prime Centre Singapore 188980 Tel: 65 334 8870 Fax: 65 334 8850 Taiwan, R.O.C Microchip Technology 10F-1C 207 Tung Hua North Road Taipei, Taiwan, ROC Tel: 886 2 717 7175 Fax: 886 2 545 0139 EUROPE United Kingdom Arizona Microchip Technology Ltd. Unit 6, The Courtyard Meadow Bank, Furlong Road Bourne End, Buckinghamshire SL8 5AJ Tel: 44 1628 850303 Fax: 44 1628 850178 France Arizona Microchip Technology SARL Zone Industrielle de la Bonde 2 Rue du Buisson aux Fraises 91300 Massy - France Tel: 33 1 69 53 63 20 Fax: 33 1 69 30 90 79 Germany Arizona Microchip Technology GmbH Gustav-Heinemann-Ring 125 D-81739 Muenchen, Germany Tel: 49 89 627 144 0 Fax: 49 89 627 144 44 Italy Arizona Microchip Technology SRL Centro Direzionale Colleone Pas Taurus 1 Viale Colleoni 1 20041 Agrate Brianza Milan Italy Tel: 39 39 6899939 Fax: 39 39 689 9883 JAPAN Microchip Technology Intl. Inc. Benex S-1 6F 3-18-20, Shin Yokohama Kohoku-Ku, Yokohama Kanagawa 222 Japan Tel: 81 45 471 6166 Fax: 81 45 471 6122 9/3/96 All rights reserved. (c) 1996, Microchip Technology Incorporated, USA. 9/96 Printed on recycled paper. Information contained in this publication regarding device applications and the like is intended through suggestion only and may be superseded by updates. No representation or warranty is given and no liability is assumed by Microchip Technology Incorporated with respect to the accuracy or use of such information, or infringement of patents or other intellectual property rights arising from such use or otherwise. Use of Microchip's products as critical components in life support systems is not authorized except with express written approval by Microchip. No licenses are conveyed, implicitly or otherwise, under any intellectual property rights. The Microchip logo and name are registered trademarks of Microchip Technology Inc. All rights reserved. All other trademarks mentioned herein are the property of their respective companies. DS21144B-page 12 Preliminary (c) 1996 Microchip Technology Inc. |
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