Advanced CAT28HT64 Extended Temperature: 170˚C 64K-Bit CMOS PARALLEL E2PROM FEATURES ■ Fast Read Access Times: ■ Hardware and Software Write Protection – 150/200ns ■ Automatic Page Write Operation: ■ Low Power CMOS Dissipation: – 1 to 32 Bytes in 5ms – Page Load Timer – Active: 25 mA Max. – Standby: 300 µA Max. ■ End of Write Detection: ■ Simple Write Operation: – Toggle Bit – DATA Polling – On-Chip Address and Data Latches – Self-Timed Write Cycle with Auto-Clear ■ 100,000 Program/Erase Cycles ■ Fast Write Cycle Time: ■ 100 Year Data Retention – 5ms Max. ■ CMOS and TTL Compatible I/O DESCRIPTION The CAT28HT64 is a fast, low power, 5V-only CMOS parallel E2PROM organized as 8K x 8-bits. It requires a simple interface for in-system programming. On-chip address and data latches, self-timed write cycle with auto-clear and VCC power up/down write protection eliminate additional timing and protection hardware. DATA Polling and Toggle status bits signal the start and end of the self-timed write cycle. Additionally, the CAT28HT64 features hardware and software write protection. The CAT28HT64 is manufactured using Catalyst’s advanced CMOS floating gate technology. It is designed to endure 100,000 program/erase cycles and has a data retention of 100 years. The device is available in JEDECapproved 28-pin Ceramic DIP package. BLOCK DIAGRAM A5–A12 ADDR. BUFFER & LATCHES ROW DECODER VCC INADVERTENT WRITE PROTECTION HIGH VOLTAGE GENERATOR CE OE WE CONTROL LOGIC 32 BYTE PAGE REGISTER I/O BUFFERS TIMER A0–A4 8,192 x 8 E2PROM ARRAY DATA POLLING AND TOGGLE BIT ADDR. BUFFER & LATCHES I/O0–I/O7 COLUMN DECODER 5094 FHD F02 © 1998 by Catalyst Semiconductor, Inc. Characteristics subject to change without notice 8-39 CAT28HT64 Advanced PIN CONFIGURATION PIN FUNCTIONS CERDIP Package (D) Pin Name Function NC A12 A7 A6 1 2 28 27 VCC WE A0–A12 Address Inputs 3 4 26 25 NC A8 I/O0–I/O7 Data Inputs/Outputs A5 A4 A3 5 6 24 23 22 A9 A11 CE Chip Enable OE Output Enable 21 A10 CE WE Write Enable VCC 5V Supply 17 I/O7 I/O6 I/O5 VSS Ground 16 15 I/O4 I/O3 NC No Connect I/O Power A2 A1 A0 7 8 9 10 I/O0 I/O1 11 12 I/O2 VSS 13 14 OE 20 19 18 MODE SELECTION Mode CE WE OE Read L H L DOUT ACTIVE Byte Write (WE Controlled) L H DIN ACTIVE L H DIN ACTIVE Byte Write (CE Controlled) Standby, and Write Inhibit H X X High-Z STANDBY Read and Write Inhibit X H H High-Z ACTIVE CAPACITANCE TA = 25°C, f = 1.0 MHz, VCC = 5V Symbol Test Max. Units Conditions CI/O(1) Input/Output Capacitance 10 pF VI/O = 0V CIN(1) Input Capacitance 6 pF VIN = 0V RELIABILITY CHARACTERISTICS Symbol Units Test Method Endurance 105 Cycles/Byte MIL-STD-883, Test Method 1033 TDR(1) Data Retention 100 Years MIL-STD-883, Test Method 1008 VZAP(1) ESD Susceptibility 2000 Volts MIL-STD-883, Test Method 3015 ILTH(1)(2) Latch-Up 100 mA NEND (1) Parameter Min. Max. JEDEC Standard 17 Note: (1) This parameter is tested initially and after a design or process change that affects the parameter. (2) Latch-up protection is provided for stresses up to 100mA on address and data pins from –1V to VCC +1V. Stock No. 21064-04 2/98 8-40 CAT28HT64 Advanced ABSOLUTE MAXIMUM RATINGS* *COMMENT Temperature Under Bias ................. –55°C to +170°C Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions outside of those listed in the operational sections of this specification is not implied. Exposure to any absolute maximum rating for extended periods may affect device performance and reliability. Storage Temperature ....................... –65°C to +170°C Voltage on Any Pin with Respect to Ground(3) ........... –2.0V to +VCC + 2.0V VCC with Respect to Ground ............... –2.0V to +7.0V Package Power Dissipation Capability (Ta = 25°C) ................................... 1.0W Lead Soldering Temperature (10 secs) ............ 300°C Output Short Circuit Current(4) ........................ 100 mA D.C. OPERATING CHARACTERISTICS VCC = 5V ±10%, unless otherwise specified. (Temperature 0˚C to 170˚C) Limits Symbol Parameter Min. Typ. Max. Units Test Conditions ICC VCC Current (Operating, TTL) 30 mA CE = OE = VIL, f = 1/tRC min, All I/O’s Open ICCC(1) VCC Current (Operating, CMOS) 25 mA CE = OE = VILC, f = 1/tRC min, All I/O’s Open ISB VCC Current (Standby, TTL) 1 mA CE = VIH, All I/O’s Open ISBC(2) VCC Current (Standby, CMOS) 300 µA CE = VIHC, All I/O’s Open ILI Input Leakage Current –10 20 µA VIN = GND to VCC ILO Output Leakage Current –10 20 µA VOUT = GND to VCC, CE = VIH VIH(2) High Level Input Voltage 2 VCC +0.3 V VIL(1) Low Level Input Voltage –0.3 0.8 V VOH High Level Output Voltage 2.4 VOL Low Level Output Voltage VWI Write Inhibit Voltage 0.4 3.5 V IOH = –400µA V IOL = 2.1mA V Note: (1) VILC = –0.3V to +0.3V. (2) VIHC = VCC –0.3V to VCC +0.3V. (3) The minimum DC input voltage is –0.5V. During transitions, inputs may undershoot to –2.0V for periods of less than 20 ns. Maximum DC voltage on output pins is VCC +0.5V, which may overshoot to VCC +2.0V for periods of less than 20 ns. (4) Output shorted for no more than one second. No more than one output shorted at a time. 8-41 Stock No. 21064-04 2/98 CAT28HT64 Advanced A.C. CHARACTERISTICS, Read Cycle VCC = 5V ±10%, unless otherwise specified. (Temperature 0˚C to 170˚C) Symbol Parameter 28HT64-15 28HT64-20 Min. Min. Max. 150 Max. 200 Units tRC Read Cycle Time tCE CE Access Time 150 200 ns tAA Address Access Time 150 200 ns tOE OE Access Time 70 80 ns tLZ(1) CE Low to Active Output 0 0 ns tOLZ(1) OE Low to Active Output 0 0 ns tHZ(1)(2) CE High to High-Z Output 50 55 ns tOHZ(1)(2) OE High to High-Z Output 50 55 ns tOH(1) Output Hold from Address Change 0 0 ns ns Figure 1. A.C. Testing Input/Output Waveform(3) 2.4 V 2.0 V INPUT PULSE LEVELS REFERENCE POINTS 0.8 V 0.45 V 5096 FHD F03 Figure 2. A.C. Testing Load Circuit (example) 1.3V 1N914 3.3K DEVICE UNDER TEST OUT CL = 100 pF CL INCLUDES JIG CAPACITANCE 5096 FHD F04 Note: (1) This parameter is tested initially and after a design or process change that affects the parameter. (2) Output floating (High-Z) is defined as the state when the external data line is no longer driven by the output buffer. (3) Input rise and fall times (10% and 90%) < 10 ns. Stock No. 21064-04 2/98 8-42 CAT28HT64 Advanced A.C. CHARACTERISTICS, Write Cycle VCC = 5V ±10%, unless otherwise specified. (Temperature 0˚C to 170˚C) Symbol Parameter 28HT64-12 28HT64-15 28HT64-20 Min. Min. Min. Max. 5 Max. 5 Max. Units 5 ms tWC Write Cycle Time tAS Address Setup Time 0 0 0 ns tAH Address Hold Time 100 100 100 ns tCS CE Setup Time 0 0 0 ns tCH CE Hold Time 0 0 0 ns tCW(2) CE Pulse Time 110 110 110 ns tOES OE Setup Time 0 0 0 ns tOEH OE Hold Time 0 0 0 ns tWP(2) WE Pulse Width 110 110 110 ns tDS Data Setup Time 60 60 60 ns tDH Data Hold Time 0 0 0 ns tINIT(1) Write Inhibit Period After Power-up 5 10 5 10 5 10 ms tBLC(1)(3) Byte Load Cycle Time .05 100 .05 100 .05 100 µs Note: (1) This parameter is tested initially and after a design or process change that affects the parameter. (2) A write pulse of less than 20ns duration will not initiate a write cycle. (3) A timer of duration tBLC max. begins with every LOW to HIGH transition of WE. If allowed to time out, a page or byte write will begin; however a transition from HIGH to LOW within tBLC max. stops the timer. 8-43 Stock No. 21064-04 2/98 CAT28HT64 Advanced Byte Write DEVICE OPERATION A write cycle is executed when both CE and WE are low, and OE is high. Write cycles can be initiated using either WE or CE, with the address input being latched on the falling edge of WE or CE, whichever occurs last. Data, conversely, is latched on the rising edge of WE or CE, whichever occurs first. Once initiated, a byte write cycle automatically erases the addressed byte and the new data is written within 5 ms. Read Data stored in the CAT28HT64 is transferred to the data bus when WE is held high, and both OE and CE are held low. The data bus is set to a high impedance state when either CE or OE goes high. This 2-line control architecture can be used to eliminate bus contention in a system environment. Figure 3. Read Cycle tRC ADDRESS tCE CE tOE OE VIH tLZ WE tOHZ DATA OUT tHZ tOH tOLZ HIGH-Z DATA VALID DATA VALID tAA 28HT64 F06 Figure 4. Byte Write Cycle [WE Controlled] tWC ADDRESS tAS tAH tCH tCS CE OE tOES tWP tOEH WE tBLC DATA OUT DATA IN HIGH-Z DATA VALID tDS tDH 5096 FHD F06 Stock No. 21064-04 2/98 8-44 CAT28HT64 Advanced Page Write (which can be loaded in any order) during the first and subsequent write cycles. Each successive byte load cycle must begin within tBLC MAX of the rising edge of the preceding WE pulse. There is no page write window limitation as long as WE is pulsed low within tBLC MAX. The page write mode of the CAT28HT64 (essentially an extended BYTE WRITE mode) allows from 1 to 32 bytes of data to be programmed within a single E2PROM write cycle. This effectively reduces the byte-write time by a factor of 32. Upon completion of the page write sequence, WE must stay high a minimum of tBLC MAX for the internal automatic program cycle to commence. This programming cycle consists of an erase cycle, which erases any data that existed in each addressed cell, and a write cycle, which writes new data back into the cell. A page write will only write data to the locations that were addressed and will not rewrite the entire page. Following an initial WRITE operation (WE pulsed low, for tWP, and then high) the page write mode can begin by issuing sequential WE pulses, which load the address and data bytes into a 32 byte temporary buffer. The page address where data is to be written, specified by bits A5 to A12, is latched on the last falling edge of WE. Each byte within the page is defined by address bits A0 to A4 Figure 5. Byte Write Cycle [CE Controlled] tWC ADDRESS tAS tAH tBLC tCW CE tOEH OE tCS tOES tCH WE HIGH-Z DATA OUT DATA IN DATA VALID tDS tDH 5094 FHD F07 Figure 6. Page Mode Write Cycle OE CE t WP t BLC WE ADDRESS t WC I/O LAST BYTE BYTE 0 BYTE 1 BYTE 2 BYTE n BYTE n+1 BYTE n+2 5096 FHD F10 8-45 Stock No. 21064-04 2/98 CAT28HT64 Advanced DATA Polling Toggle Bit DATA polling is provided to indicate the completion of write cycle. Once a byte write or page write cycle is initiated, attempting to read the last byte written will output the complement of that data on I/O7 (I/O0–I/O6 are indeterminate) until the programming cycle is complete. Upon completion of the self-timed write cycle, all I/O’s will output true data during a read cycle. In addition to the DATA Polling feature, the device offers an additional method for determining the completion of a write cycle. While a write cycle is in progress, reading data from the device will result in I/O6 toggling between one and zero. However, once the write is complete, I/O6 stops toggling and valid data can be read from the device. Figure 7. DATA Polling ADDRESS CE WE tOEH tOES tOE OE tWC I/O7 DIN = X DOUT = X DOUT = X 28HT64 F10 Figure 8. Toggle Bit WE CE tOEH tOES tOE OE I/O6 (1) (1) tWC 28HT64 F11 Note: (1) Beginning and ending state of I/O6 is indeterminate. Stock No. 21064-04 2/98 8-46 CAT28HT64 Advanced HARDWARE DATA PROTECTION The following is a list of hardware data protection features that are incorporated into the CAT28HT64. (1) VCC sense provides for write protection when VCC falls below 3.5V min. (2) A power on delay mechanism, tINIT (see AC characteristics), provides a 5 to 10 ms delay before a write sequence, after VCC has reached 3.5V min. (4) Noise pulses of less than 20 ns on the WE or CE inputs will not result in a write cycle. SOFTWARE DATA PROTECTION The CAT28HT64 features a software controlled data protection scheme which, once enabled, requires a data algorithm to be issued to the device before a write can be performed. The device is shipped from Catalyst with the software protection NOT ENABLED (the CAT28HT64 is in the standard operating mode). (3) Write inhibit is activated by holding any one of OE low, CE high or WE high. Figure 9. Write Sequence for Activating Software Data Protection WRITE DATA: ADDRESS: WRITE DATA: ADDRESS: WRITE DATA: ADDRESS: Figure 10. Write Sequence for Deactivating Software Data Protection WRITE DATA: AA ADDRESS: 1555 WRITE DATA: 55 ADDRESS: 0AAA WRITE DATA: A0 ADDRESS: 1555 SOFTWARE DATA (1) PROTECTION ACTIVATED WRITE DATA: WRITE DATA: XX WRITE DATA: TO ANY ADDRESS ADDRESS: WRITE LAST BYTE TO LAST ADDRESS WRITE DATA: ADDRESS: ADDRESS: 5094 FHD F08 AA 1555 55 0AAA 80 1555 AA 1555 55 0AAA 20 1555 5094 FHD F09 Note: (1) Write protection is activated at this point whether or not any more writes are completed. Writing to addresses must occur within tBLC Max., after SDP activation. 8-47 Stock No. 21064-04 2/98 CAT28HT64 Advanced To activate the software data protection, the device must be sent three write commands to specific addresses with specific data (Figure 9). This sequence of commands (along with subsequent writes) must adhere to the page write timing specifications (Figure 11). Once this is done, all subsequent byte or page writes to the device must be preceded by this same set of write commands. The data protection mechanism is activated until a deactivate sequence is issued regardless of power on/off transitions. This gives the user added inadvertent write protection on power-up in addition to the hardware protection provided. To allow the user the ability to program the device with an E2PROM programmer (or for testing purposes) there is a software command sequence for deactivating the data protection. The six step algorithm (Figure 10) will reset the internal protection circuitry, and the device will return to standard operating mode (Figure 12 provides reset timing). After the sixth byte of this reset sequence has been issued, standard byte or page writing can commence. Figure 11. Software Data Protection Timing DATA ADDRESS AA 1555 55 0AAA tWC A0 1555 CE tWP tBLC BYTE OR PAGE WRITES ENABLED WE 5094 FHD F13 Figure 12. Resetting Software Data Protection Timing DATA ADDRESS AA 1555 55 0AAA 80 1555 AA 1555 55 0AAA 20 1555 tWC SDP RESET CE DEVICE UNPROTECTED WE 5094 FHD F14 ORDERING INFORMATION Prefix Device # CAT 28HT64 Suffix -20 D Product Number Optional Company ID Package D: CERDIP Speed 15: 150ns 20: 200ns Notes: (1) The device used in the above example is a CAT28HT64D-20 (CERDIP, 200 ns Access Time). Stock No. 21064-04 2/98 8-48 28HT64 F15