24FC32 32K 5.0V 1 MHz I2C Smart Serial EEPROM FEATURES PACKAGE TYPES -40˚C to +85˚C DESCRIPTION A0 1 8 VCC A1 2 7 NC A2 3 6 SCL VSS 4 5 SDA A0 1 8 VCC A1 2 7 NC A2 3 6 SCL VSS 4 5 SDA SOIC 24FC32 - Industrial (I): PDIP 24FC32 • Voltage operating range: 4.5V to 5.5V - Maximum write current 3 mA at 5.5V - Maximum read current 150 µA at 5.5V - Standby current 1 µA typical • 1 MHz SE2.bus two wire protocol • Self-timed write cycle (including auto-erase) • Power on/off data protection circuitry • Endurance: - 10,000,000 Erase/Write cycles guaranteed for a 4K block - 1,000,000 E/W cycles guaranteed for a 28K block • 8-byte page, or byte modes available • 1 page x 8 line input cache (64 bytes) for fast write loads • Schmitt trigger inputs for noise suppression • 2 ms typical write cycle time, byte or page • Up to 8 chips 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/SOIC packages • Temperature ranges - Commercial (C): 0˚C to +70˚C BLOCK DIAGRAM A0..A2 HV GENERATOR I/O CONTROL LOGIC MEMORY CONTROL LOGIC XDEC EEPROM ARRAY PAGE LATCHES The Microchip Technology Inc. 24FC32 is a 4K x 8 (32K bit) Serial Electrically Erasable PROM (EEPROM) with a high-speed 1 MHz SE2.bus whose protocol is functionally equivalent to the industry-standard I2C bus. This device has been developed for advanced, low power applications such as personal communications or data acquisition. The 24FC32 features an input cache for fast write loads with a capacity of eight 8-byte pages, or 64 bytes. It also features a fixed 4K-bit block of ultra-high endurance memory for data that changes frequently. The 24FC32 is capable of both random and sequential reads up to the 32K boundary. Functional address lines allow up to 8 - 24FC32 devices on the same bus, for up to 256K bits address space. The 24FC32 is available in the standard 8-pin plastic DIP and 8-pin surface mount SOIC package. I/O SCL CACHE SDA YDEC VCC VSS SENSE AMP R/W CONTROL I2C is a trademark of Philips Corporation. Smart Serial is a trademark of Microchip Technology Inc. 1996 Microchip Technology Inc. DS21126B-page 3-1 This document was created with FrameMaker 4 0 4 24FC32 1.0 ELECTRICAL CHARACTERISTICS 1.1 Maximum Ratings* TABLE 1-1: Name A0..A2 VSS SDA SCL VCC NC VCC ..................................................................................7.0V All inputs and outputs w.r.t. VSS ............... -0.6V to VCC +1.0V Storage temperature ..................................... -65˚C to +150˚C Ambient temp. with power applied ................ -65˚C to +125˚C Soldering temperature of leads (10 seconds) ............. +300˚C 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: PIN FUNCTION TABLE Function User Configurable Chip Selects Ground Serial Address/Data I/O Serial Clock +4.5V to 5.5V Power Supply No Internal Connection DC CHARACTERISTICS VCC = +4.5V to +5.5V Commercial (C): Tamb = 0˚C to +70˚C Industrial (I): Tamb = -40˚C to +85˚C Parameter A0, A1, A2, SCL and SDA pins: High level input voltage Low level input voltage Hysteresis of SCL and SDA Low level output voltage of SDA Input leakage current Output leakage current Pin capacitance (all inputs/outputs) Operating current Symbol Min Max Units VIH VIL VHYS VOL ILI ILO CINT 0.7 Vcc — 0.05 Vcc — -10 -10 — — 0.3 Vcc — 0.40 10 10 10 V V V V µA µA pF ICC WRITE ICC Read ICCS — — — 3 150 Standby current 5 (1 typical) Note 1: This parameter is periodically sampled and not 100% tested. FIGURE 1-1: mA µA µA Conditions (Note 1) IOL = 3.0 mA VIN = 0.1V TO VCC VOUT = 0.1V to VCC VCC = 5.0V (Note 1) Tamb = 25˚C, Fclk = 1 MHz VCC = 5.5V, SCL = 1 MHz VCC = 5.5V, SCL = 1 MHz VCC = 5.5V, SCL = SDA = VCC (Note 1) BUS TIMING START/STOP VHYS SCL THD:STA TSU:STA TSU:STO SDA START DS21126B-page 3-2 STOP 1996 Microchip Technology Inc. 24FC32 TABLE 1-3: AC CHARACTERISTICS 1 MHz Bus Parameter Symbol Units Min Max Remarks Clock frequency FCLK 0 1000 kHz Clock high time THIGH 500 — ns Clock low time TLOW 500 — ns SDA and SCL rise time TR — 300 ns (Note 1) SDA and SCL fall time TF — 100 ns (Note 1) START condition hold time THD:STA 250 — ns After this period the first clock pulse is generated START condition setup time TSU:STA 250 — ns Only relevant for repeated START condition Data input hold time THD:DAT 0 — ns Data input setup time TSU:DAT 100 — ns STOP condition setup time TSU:STO 250 — ns Output valid from clock TAA — 350 ns (Note 2) Bus free time TBUF 500 — ns Time the bus must be free before a new transmission can start Write cycle time TWR — 5 — — 10M 1M — — Endurance High Endurance Block Rest of Array ms/page Note 3 10M 1M 25°C, Vcc = 5.0V, Block Mode (Note 4) Note 1: Not 100 percent tested. 2: As a transmitter, the device must provide an internal minimum delay time to bridge the undefined region (minimum 100 ns) of the falling edge of SCL to avoid unintended generation of START or STOP conditions. 3: The times shown are for a single page of 8 bytes. Multiply by the number of pages loaded into the write cache for total time. 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 TR THIGH TLOW SCL TSU:STA THD:DAT TSU:DAT THD:STA SDA IN TSP TSU:STO TBUF TAA TAA SDA OUT 1996 Microchip Technology Inc. DS21126B-page 3-3 24FC32 2.0 FUNCTIONAL DESCRIPTION The 24FC32 supports a bidirectional two-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 24FC32 works as slave. Both master and slave can operate as transmitter or receiver but the master device determines which mode is activated. 3.0 BUS CHARACTERISTICS 3.4 Data Valid (D) 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. The following bus protocol has been defined: 3.5 • 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. 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: Accordingly, the following bus conditions have been defined (Figure 3-1). 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) Acknowledge The 24FC32 does not generate any acknowledge bits if an internal programming cycle is in progress. 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 (24FC32) 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) DATA TRANSFER SEQUENCE ON THE SERIAL BUS (B) (D) (D) (C) (A) SCL SDA START CONDITION DS21126B-page 3-4 ADDRESS DATA ALLOWED OR TO CHANGE ACKNOWLEDGE VALID STOP CONDITION 1996 Microchip Technology Inc. 24FC32 3.6 Device Addressing FIGURE 3-2: A control byte is the first byte received following the start condition from the master device. The control byte consists of a four bit control code; for the 24FC32 this is set as 1010 binary for read and write 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 (R/W) 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 24FC32 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 24FC32 will select a read or write operation. FIGURE 3-3: START READ/WRITE SLAVE ADDRESS 1 0 1 0 R/W A2 A1 A A0 X = Don’t care Operation Control Code Device Select R/W Read 1010 Device Address 1 Write 1010 Device Address 0 ADDRESS SEQUENCE BIT ASSIGNMENTS ADDRESS BYTE 1 CONTROL BYTE 1 CONTROL BYTE ALLOCATION 0 1 Slave Address 0 A A 2 1 A 0 R /W 0 0 0 A A A 0 11 10 9 ADDRESS BYTE 0 A 8 A 7 • • • • • • A 0 Device Select Bits 1996 Microchip Technology Inc. DS21126B-page 3-5 24FC32 4.0 WRITE OPERATION 4.3 4.1 Split Endurance The write control byte, word address and the first data byte are transmitted to the 24FC32 in the same way as in a byte write. But instead of generating a stop condition, the master transmits up to eight pages of eight data bytes each (64 bytes total) which are temporarily stored in the on-chip page cache of the 24FC32. They will be written from cache into the EEPROM array after the master has transmitted a stop condition. After the receipt of each word, the six lower order address pointer bits are internally incremented by one. The higher order seven bits of the word address remain constant. If the master should transmit more than eight bytes prior to generating the stop condition (writing across a page boundary), the address counter (lower three bits) will roll over and the pointer will be incremented to point to the next line in the cache. This can continue to occur up to eight times or until the cache is full, at which time a stop condition should be generated by the master. If a stop condition is not received, the cache pointer will roll over to the first line (byte 0) of the cache, and any further data received will overwrite previously captured data. The stop condition can be sent at any time during the transfer. As with the byte write operation, once a stop condition is received, an internal write cycle will begin. The 64-byte cache will continue to capture data until a stop condition occurs or the operation is aborted (Figure 4-2). The 24FC32 is organized as a continuous 32K block of memory. However, the first 4K, starting at address 000, is rated at 10,000,000 E/W cycles guaranteed. The remainder of the array, 28K bits, is rated at 100K E/W cycles guaranteed. This feature is helpful in applications in which some data change frequently, while a majority of the data change infrequently. One example would be a cellular telephone in which last-number redial and microcontroller scratch pad require a high-endurance block, while speed dials and lookup tables change infrequently and so require only a standard endurance rating. 4.2 Byte 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 24FC32. The next byte is the least significant address byte. After receiving another acknowledge signal from the 24FC32 the master device will transmit the data word to be written into the addressed memory location. The 24FC32 acknowledges again and the master generates a stop condition. This initiates the internal write cycle, and during this time the 24FC32 will not generate acknowledge signals (Figure 4-1). FIGURE 4-1: BYTE WRITE BUS ACTIVITY: MASTER S T A R T CONTROL BYTE WORD ADDRESS (1) A C K BUS ACTIVITY BUS ACTIVITY MASTER T A R T WORD ADDRESS (0) S T O P DATA 0 0 0 0 SDA LINE FIGURE 4-2: S Page Write A C K A C K A C K PAGE WRITE WORD ADDRESS (1) CONTROL BYTE SDA LINE BUS ACTIVITY DS21126B-page 3-6 WORD ADDRESS (0) S T O P DATA n+7 DATA n 0 0 0 0 A C K A C K A C K A C K A C K 1996 Microchip Technology Inc. 24FC32 5.0 ACKNOWLEDGE POLLING 6.0 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. ACK polling 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. FIGURE 5-1: ACKNOWLEDGE POLLING FLOW Send Write Command 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 Random Read 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 24FC32 as part of a write operation (R/W bit set to 0). 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 24FC32 will then issue an acknowledge and transmit the eight bit data word. The master will not acknowledge the transfer but does generate a stop condition which causes the 24FC32 to discontinue transmission (Figure 6-2). Send Start Send Control Byte with R/W = 0 Did Device Acknowledge (ACK = 0)? Current Address Read The 24FC32 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 24FC32 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 24FC32 discontinues transmission (Figure 6-1). 6.2 Send Stop Condition to Initiate Write Cycle READ OPERATION No Yes Next Operation FIGURE 6-1: CURRENT ADDRESS READ BUS ACTIVITY MASTER S T A R T CONTROL BYTE S T O P DATA n SDA LINE BUS ACTIVITY 1996 Microchip Technology Inc. A C K N O A C K DS21126B-page 3-7 24FC32 6.3 Contiguous Addressing Across Multiple Devices To provide sequential reads the 24FC32 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 address pointer, however, will not roll over from address 07FF to address 0000. It will roll from 07FF to unused memory space. 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 24FC32'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. 6.4 6.5 The SCL and SDA inputs incorporate Schmitt triggers which suppress noise spikes to ensure proper device operation even on a noisy bus. Sequential Read Sequential reads are initiated in the same way as a random read except that after the 24FC32 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 24FC32 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. FIGURE 6-2: S T BUS A ACTIVITY: R MASTER T Noise Protection RANDOM READ WORD ADDRESS (1) CONTROL BYTE CONTROL BYTE S T O P DATA n 0 0 0 0 SDA LINE A C K A C K BUS ACTIVITY: FIGURE 6-3: S T A R T WORD ADDRESS (0) A C K N O A C K A C K SEQUENTIAL READ BUS ACTIVITY MASTER CONTROL BYTE DATA n DATA n + 1 DATA n + 2 S T O P DATA n + X P SDA LINE BUS ACTIVITY A C K A C K A C K A C K N O A C K DS21126B-page 3-8 1996 Microchip Technology Inc. 24FC32 7.0 PAGE CACHE AND ARRAY MAPPING The cache is a 64 byte (8 pages x 8 bytes) FIFO buffer. The cache allows the loading of up to 64 bytes of data before the write cycle is actually begun, effectively providing a 64-byte burst write at the maximum bus rate. Whenever a write command is initiated, the cache starts loading and will continue to load until a stop bit is received to start the internal write cycle. The total length of the write cycle will depend on how many pages are loaded into the cache before the stop bit is given. Maximum cycle time for each page is 5 ms. Even if a page is only partially loaded, it will still require the same cycle time as a full page. If more than 64 bytes of data are loaded before the stop bit is given, the address pointer will' wrap around' to the beginning of cache page 0 and existing bytes in the cache will be overwritten. The device will not respond to any commands while the write cycle is in progress. 7.1 Cache Write Starting at a Page Boundary If a write command begins at a page boundary (address bits A2, A1 and A0 are zero), then all data loaded into the cache will be written to the array in sequential addresses. This includes writing across a 4K block boundary. In the example shown below, (Figure 7-1) a write command is initiated starting at byte 0 of page 3 with a fully loaded cache (64 bytes). The first byte in the cache is written to byte 0 of page 3 (of the array), with the remaining pages in the cache written to sequential pages in the array. A write cycle is executed after each page is written. Since the write begins at page 3 and 8 pages are loaded into the cache, the last 3 pages of the cache are written to the next row in the array. 1996 Microchip Technology Inc. 7.2 Cache Write Starting at a Non-Page Boundary When a write command is initiated that does not begin at a page boundary (i.e., address bits A2, A1 and A0 are not all zero), it is important to note how the data is loaded into the cache, and how the data in the cache is written to the array. When a write command begins, the first byte loaded into the cache is always loaded into page 0. The byte within page 0 of the cache where the load begins is determined by the three least significant address bits (A2, A1, A0) that were sent as part of the write command. If the write command does not start at byte 0 of a page and the cache is fully loaded, then the last byte(s) loaded into the cache will roll around to page 0 of the cache and fill the remaining empty bytes. If more than 64 bytes of data are loaded into the cache, data already loaded will be overwritten. In the example shown in Figure 7-2, a write command has been initiated starting at byte 2 of page 3 in the array with a fully loaded cache of 64 bytes. Since the cache started loading at byte 2, the last two bytes loaded into the cache will 'roll over' and be loaded into the first two bytes of page 0 (of the cache). When the stop bit is sent, page 0 of the cache is written to page 3 of the array. The remaining pages in the cache are then loaded sequentially to the array. A write cycle is executed after each page is written. If a partially loaded page in the cache remains when the STOP bit is sent, only the bytes that have been loaded will be written to the array. 7.3 Power Management 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, ie. not receiving an acknowledge or stop condition per the two-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. DS21126B-page 3-9 24FC32 FIGURE 7-1: 1 CACHE WRITE TO THE ARRAY STARTING AT A PAGE BOUNDARY Write command initiated at byte 0 of page 3 in the array; First data byte is loaded into the cache byte 0. 2 64 bytes of data are loaded into cache. cache page 0 cache byte 0 3 cache byte 1 • • • cache byte 7 cache page 1 bytes 8-15 cache page 2 bytes 16-23 Write from cache into array initiated by STOP bit. Page 0 of cache written to page 3 of array. Write cycle is executed after every page is written. page 0 page 1 page 2 byte 0 byte 1 • • • page 0 page 1 page 2 page 3 4 • • • cache page 7 bytes 56-63 Remaining pages in cache are written to sequential pages in array. byte 7 page 4 • • • page 7 array row n page 4 • • • page 7 array row n + 1 5 Last page in cache written to page 2 in next row. FIGURE 7-2: CACHE WRITE TO THE ARRAY STARTING AT A NON-PAGE BOUNDARY 1 3 cache byte 0 Write command initiated; 64 bytes of data loaded into cache starting at byte 2 of page 0. cache byte 1 cache byte 2 Last 2 bytes loaded into page 0 of cache. 4 • • • cache byte 7 2 Last 2 bytes ‘roll ever’ to beginning. cache page 1 cache page 2 bytes 8-15 bytes 16-23 Write from cache into array initiated by STOP bit. Page 0 of cache written to page 3 of array. Write cycle is executed after every page is written. • • • 5 cache page 7 bytes 56-63 Remaining bytes in cache are written sequentially to array. array row n page 0 page 1 page 2 byte 0 byte 1 byte 2 byte 3 byte 4 • • • byte 7 page 4 • • • page 7 page 0 page 1 page 2 page 3 page 4 • • • page 7 array row n+1 6 Last 3 pages in cache written to next row in array. DS21126B-page 3-10 1996 Microchip Technology Inc. 24FC32 8.0 PIN DESCRIPTIONS 8.1 A0, A1, A2 Chip Address Inputs The A0..A2 inputs are used by the 24FC32 for multiple device operation and conform to the two-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). 8.2 SDA Serial Address/Data Input/Output This is a bidirectional 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 1KΩ, must consider total bus capacitance and maximum rise/fall times). 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. 8.3 SCL Serial Clock This input is used to synchronize the data transfer from and to the device. 1996 Microchip Technology Inc. DS21126B-page 3-11 24FC32 24FC32 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. 24FC32 – /P Package: P = Plastic DIP (300 mil Body) SM = Plastic SOIC (207 mil Body, EIAJ standard) Temperature Range: Device: Blank = 0°C to +70°C I = -40°C to +85°C 24FC32 24FC32T 32K, 1MHz I2C Serial EEPROM 32K, 1MHz I2C Serial EEPROM (Tape & Reel) AMERICAS AMERICAS (CONT) EUROPE 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 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 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 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. Printed on recycled paper. 1996, Microchip Technology Incorporated 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. DS21126B-page 3-12 1996 Microchip Technology Inc.