AT28C17 Features • • • • • • • • • • Fast Read Access Time - 150 ns Fast Byte Write - 200 µs or 1 ms Self-Timed Byte Write Cycle Internal Address and Data Latches Internal Control Timer Automatic Clear Before Write Direct Microprocessor Control DATA POLLING READY/BUSY Open Drain Output Low Power 30 mA Active Current 100 µa CMOS Standby Current High Reliability Endurance: 104 or 105 Cycles Data Retention: 10 Years 5V ± 10% Supply CMOS & TTL Compatible Inputs and Outputs JEDEC Approved Byte Wide Pinout Commercial and Industrial Temperature Ranges 16K (2K x 8) CMOS E2PROM Description The AT28C17 is a low-power, high-performance Electrically Erasable and Programmable Read Only Memory with easy to use features. The AT28C17 is a 16K memory organized as 2,048 words by 8 bits. The device is manufactured with Atmel’s reliable nonvolatile CMOS technology. (continued) Pin Configurations Pin Name Function A0 - A10 Addresses CE Chip Enable OE Output Enable WE Write Enable I/O0 - I/O7 Data Inputs/Outputs RDY/BUSY Ready/Busy Output NC No Connect DC Don’t Connect PDIP, SOIC Top View AT28C17 PLCC Top View Note: PLCC package pins 1 and 17 are DON’T CONNECT. 0541A 2-183 Description (Continued) The AT28C17 is accessed like a static RAM for the read or write cycles without the need of external components. During a byte write, the address and data are latched internally, freeing the microprocessor address and data bus for other operations. Following the initiation of a write cycle, the device will go to a busy state and automatically clear and write the latched data using an internal control timer. The device includes two methods for detecting the end of a write cycle, level detection of RDY/BUSY and DATA POLLING of I/O7. Once the end of a write cycle has been detected, a new access for a read or a write can begin. The CMOS technology offers fast access times of 150 ns at low power dissipation. When the chip is deselected the standby current is less than 100 µA. Atmel’s 28C17 has additional features to ensure high quality and manufacturability. The device utilizes error correction internally for extended endurance and for improved data retention characteristics. An extra 32-bytes of E2PROM are available for device identification or tracking. Block Diagram Absolute Maximum Ratings* Temperature Under Bias................. -55°C to +125°C Storage Temperature...................... -65°C to +150°C All Input Voltages (including NC Pins) with Respect to Ground ................... -0.6V to +6.25V All Output Voltages with Respect to Ground .............-0.6V to VCC + 0.6V Voltage on OE and A9 with Respect to Ground ................... -0.6V to +13.5V 2-184 AT28C17 *NOTICE: Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. AT28C17 Device Operation READ: The AT28C17 is accessed like a Static RAM. When CE and OE are low and WE is high, the data stored at the memory location determined by the address pins is asserted on the outputs. The outputs are put in a high impedance state whenever CE or OE is high. This dual line control gives designers increased flexibility in preventing bus contention. BYTE WRITE: Writing data into the AT28C17 is similar to writing into a Static RAM. A low pulse on the WE or CE input with OE high and CE or WE low (respectively) initiates a byte write. The address location is latched on the last falling edge of WE (or CE); the new data is latched on the first rising edge. Internally, the device performs a selfclear before write. Once a byte write has been started, it will automatically time itself to completion. Once a programming operation has been initiated and for the duration of tWC, a read operation will effectively be a polling operation. FAST BYTE WRITE: The AT28C17E offers a byte write time of 200 µs maximum. This feature allows the entire device to be rewritten in 0.4 seconds. READY/BUSY: Pin 1 is an open drain READY/BUSY output that can be used to detect the end of a write cycle. RDY/BUSY is actively pulled low during the write cycle and is released at the completion of the write. The open drain connection allows for OR-tying of several devices to the same RDY/BUSY line. DATA POLLING: The AT28C17 provides DATA POLLING to signal the completion of a write cycle. During a write cycle, an attempted read of the data being written results in the complement of that data for I/O7 (the other outputs are indeterminate). When the write cycle is finished, true data appears on all outputs. WRITE PROTECTION: Inadvertent writes to the device are protected against in the following ways. (a) VCC sense— if VCC is below 3.8V (typical) the write function is inhibited. (b) VCC power on delay— once VCC h a s reached 3.8V the device will automatically time out 5 ms (typical) before allowing a byte write. (c) Write Inhibit— holding any one of OE low, CE high or WE high inhibits byte write cycles. CHIP CLEAR: The contents of the entire memory of the AT28C17 may be set to the high state by the CHIP CLEAR operation. By setting CE low and OE to 12 volts, the chip is cleared when a 10 msec low pulse is applied to WE. DEVICE IDENTIFICATION: A n e x t r a 3 2 - b y t e s o f E2PROM memory are available to the user for device identification. By raising A9 to 12 ± 0.5V and using address locations 7E0H to 7FFH the additional bytes may be written to or read from in the same manner as the regular memory array. 2-185 DC and AC Operating Range AT28C17-15 Com. Operating Temperature (Case) 0°C - 70°C Ind. -40°C - 85°C 5V ± 10% VCC Power Supply Operating Modes Mode CE OE WE I/O Read VIL VIL VIH DOUT VIL VIH VIL DIN VIH (1) Write (2) Standby/Write Inhibit X X High Z Write Inhibit X X VIH Write Inhibit X VIL X Output Disable X VIH X High Z VIL High Z Chip Erase VH VIL (3) 3. VH = 12.0V ± 0.5V. Notes: 1. X can be VIL or VIH. 2. Refer to AC Programming Waveforms. DC Characteristics Symbol Parameter Condition Min Max Units ILI Input Load Current VIN = 0V to VCC + 1V 10 µA ILO Output Leakage Current VI/O = 0V to VCC 10 µA ISB1 VCC Standby Current CMOS CE = VCC - 0.3V to VCC + 1.0V 100 µA ISB2 VCC Standby Current TTL CE = 2.0V to VCC + 1.0V Com. 2 mA Ind. 3 mA ICC VCC Active Current AC f = 5 MHz; IOUT = 0 mA CE = VIL Com. 30 mA Ind. 45 mA VIL Input Low Voltage 0.8 V VIH Input High Voltage VOL Output Low Voltage IOL = 2.1 mA = 4.0 for RDY/BUSY VOH Output High Voltage IOH = -400 µA 2-186 AT28C17 2.0 V .4 2.4 V V AT28C17 AC Read Characteristics AT28C17-15 Symbol Parameter tACC Min Max Units Address to Output Delay 150 ns tCE (1) CE to Output Delay 150 ns tOE (2) OE to Output Delay 10 70 ns tDF (3, 4) CE or OE High to Output Float 0 50 ns Output Hold from OE, CE or Address, whichever occurred first 0 tOH ns AC Read Waveforms (1, 2, 3, 4) Notes: 1. CE may be delayed up to tACC - tCE after the address transition without impact on tACC. 2. OE may be delayed up to tCE - tOE after the falling edge of CE without impact on tCE or by tACC - tOE after an address change without impact on tACC. 3. tDF is specified from OE or CE whichever occurs first (CL = 5 pF). 4. This parameter is characterized and is not 100% tested. Input Test Waveforms and Measurement Level Output Test Load tR, tF < 20 ns Pin Capacitance (f = 1 MHz, T = 25°C) (1) Typ Max Units CIN 4 6 pF VIN = 0V COUT 8 12 pF VOUT = 0V Note: Conditions 1. This parameter is characterized and is not 100% tested. 2-187 AC Write Characteristics Symbol Parameter Min tAS, tOES Address, OE Set-up Time 10 ns tAH Address Hold Time 50 ns tWP Write Pulse Width (WE or CE) 100 tDS Data Set-up Time 50 ns tDH, tOEH Data, OE Hold Time 10 ns tCS, tCH CE to WE and WE to CE Set-up and Hold Time 0 ns tDB Time to Device Busy tWC Write Cycle Time AC Write Waveforms WE Controlled CE Controlled 2-188 AT28C17 Typ Max 1000 Units ns 50 ns AT28C17 0.5 1.0 ms AT28C17E 100 200 µs AT28C17 Data Polling Characteristics (1) Symbol Parameter tDH Data Hold Time tOEH OE Hold Time Min OE to Output Delay tWR Write Recovery Time Max Units 10 ns 10 ns (2) tOE Typ ns 0 ns Notes: 1. These parameters are characterized and not 100% tested. 2. See AC Read Characteristics. Data Polling Waveforms Chip Erase Waveforms tS = tH = 1 µsec (min.) tW = 10 msec (min.) VH = 12.0V ± 0.5V 2-189 2-190 AT28C17 AT28C17 Ordering Information (1) tACC ICC (mA) Ordering Code Package 0.1 AT28C17(E)-15JC AT28C17(E)-15PC AT28C17(E)-15SC 32J 28P6 28S Commercial (0°C to 70°C) 45 0.1 AT28C17(E)-15JI AT28C17(E)-15PI AT28C17(E)-15SI 32J 28P6 28S Industrial (-40°C to 85°C) 30 0.1 AT28C17-W DIE (ns) Active Standby 150 30 250 Operation Range Commercial (0°C to 70°C) Notes: 1. See Valid Part Number table below. 2. The 28C17 200 ns and 250 ns speed selections have been removed from valid selections table and are replaced by the faster 150 ns TAA offering. 3. The 28C17 ceramic and LCC package offerings have been removed. New designs should utilize the 28C256 ceramic offerings. Valid Part Numbers The following table lists standard Atmel products that can be ordered. Device Numbers Speed Package and Temperature Combinations AT28C17 15 JC, JI, PC, PI, SC, SI AT28C17E 15 JC, JI, PC, PI, SC, SI AT28C17 - W Package Type 32J 32 Lead, Plastic J-Leaded Chip Carrier (PLCC) 28P6 28 Lead, 0.600" Wide, Plastic Dual Inline Package (PDIP) 28S 28 Lead, 0.300" Wide, Plastic Gull Wing, Small Outline (SOIC) W Die Options Blank Standard Device: Endurance = 10K Write Cycles; Write Time = 1 ms E High Endurance Option: Endurance = 100K Write Cycles; Write Time = 200 µs 2-191