AT29BV020 Features • • • • • • • • • • • • • Single Supply Voltage, Range 2.7V to 3.6V Single Supply for Read and Write Software Protected Programming Fast Read Access Time - 250 ns Low Power Dissipation 15 mA Active Current 20 µA CMOS Standby Current Sector Program Operation Single Cycle Reprogram (Erase and Program) 1024 Sectors (256 bytes/sector) Internal Address and Data Latches for 256-Bytes Two 8 KB Boot Blocks with Lockout Fast Sector Program Cycle Time - 20 ms Max. Internal Program Control and Timer DATA Polling for End of Program Detection Typical Endurance > 10,000 Cycles CMOS and TTL Compatible Inputs and Outputs Commercial and Industrial Temperature Ranges 2 Megabit (256K x 8) Single 2.7-volt Battery-Voltage CMOS Flash Memory Description The AT29BV020 is a 2.7-volt-only in-system Flash Programmable and Erasable Read Only Memory (PEROM). Its 2 megabits of memory is organized as 262,144 words by 8 bits. Manufactured with Atmel’s advanced nonvolatile CMOS EEPROM technology, the device offers access times up to 250 ns, and a low 54 mW power dissipation. When the device is deselected, the CMOS standby current is less than 20 µA. The device endurance is such that any sector can typically be written to in excess of 10,000 times. The programming algorithm is compatible with other devices in Atmel’s Low Voltage Flash family of products. (continued) AT29BV020 Pin Configurations Pin Name Function A0 - A17 Addresses CE Chip Enable OE Output Enable WE Write Enable I/O0 - I/O7 Data Inputs/Outputs NC No Connect TSOP Top View PLCC Top View Type 1 0402B 4-13 Description (Continued) To allow for simple in-system reprogrammability, the AT29BV020 does not require high input voltages for programming. The device can be operated with a single 2.7V to 3.6V supply. Reading data out of the device is similar to reading from an EPROM. Reprogramming the AT29BV020 is performed on a sector basis; 256-bytes of data are loaded into the device and then simultaneously programmed. During a reprogram cycle, the address locations and 256bytes of data are captured at microprocessor speed and internally latched, freeing the address and data bus for other operations. Following the initiation of a program cycle, the device will automatically erase the sector and then program the latched data using an internal control timer. The end of a program cycle can be detected by DATA polling of I/O7. Once the end of a program cycle has been detected, a new access for a read or program can begin. Block Diagram Device Operation READ: The AT29BV020 is accessed like an EPROM. 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 the high impedance state whenever CE or OE is high. This dualline control gives designers flexibility in preventing bus contention. will not reset the software data protection feature, however the software feature will guard against inadvertent program cycles during power transitions. SOFTWARE DATA PROTECTION PROGRAMMING: The AT29BV020 has 1024 individual sectors, each 256bytes. Using the software data protection feature, byte loads are used to enter the 256-bytes of a sector to be programmed. The AT29BV020 can only be programmed or reprogrammed using the software data protection feature. The device is programmed on a sector basis. If a byte of data within the sector is to be changed, data for the entire 256-byte sector must be loaded into the device. The data in any byte that is not loaded during the programming of its sector will be indeterminate. The AT29BV020 automatically does a sector erase prior to loading the data into the sector. An erase command is not required. After the software data protection’s 3-byte command code is given, a byte load is performed by applying a low pulse on the WE or CE input with CE or WE low (respectively) and OE high. The address is latched on the falling edge of CE or WE, whichever occurs last. The data is latched by the first rising edge of CE or WE. Software data protection protects the device from inadvertent programming. A series of three program commands to specific addresses with specific data must be presented to the device before programming may occur. The same three program commands must begin each program operation. All software program commands must obey the sector program timing specifications. Power transitions Any attempt to write to the device without the 3-byte command sequence will start the internal write timers. No data will be written to the device; however, for the duration of tWC, a read operation will effectively be a polling operation. The 256-bytes of data must be loaded into each sector. Any byte that is not loaded during the programming of its sector will be indeterminate. Once the bytes of a sector are loaded into the device, they are simultaneously programmed during the internal programming period. After the first data byte has been loaded into the device, successive bytes are entered in the same manner. Each new byte to be programmed must have its high to low transition on WE (or CE) within 150 µs of the low to high transition of WE (or CE) of the preceding byte. If a high to low transition is not detected within 150 µs of the last low to high transition, the load period will end and the internal programming period will start. A8 to A17 specify the sector address. The (continued) 4-14 AT29BV020 AT29BV020 Device Operation (Continued) sector address must be valid during each high to low transition of WE (or CE). A0 to A7 specify the byte address within the sector. The bytes may be loaded in any order; sequential loading is not required. HARDWARE DATA PROTECTION: Hardware features protect against inadvertent programs to the AT29BV020 in the following ways: (a) VCC sense— if VCC is below 2.0V (typical), the program function is inhibited. (b) VCC power on delay— once VCC has reached the VCC sense level, the device will automatically time out 10 ms (typical) before programming. (c) Program inhibit— holding any one of OE low, CE high or WE high inhibits program cycles. (d) Noise filter— pulses of less than 15 ns (typical) on the WE or CE inputs will not initiate a program cycle. INPUT LEVELS: While operating with a 2.7V to 3.6V power supply, the address inputs and control inputs (OE, CE and WE) may be driven from 0 to 5.5V without adversely affecting the operation of the device. The I/O lines can only be driven from 0 to VCC + 0.6V. PRODUCT IDENTIFICATION: The product identification mode identifies the device and manufacturer as Atmel. It may be accessed by hardware or software operation. The hardware operation mode can be used by an external programmer to identify the correct programming algorithm for the Atmel product. In addition, users may wish to use the software product identification mode to identify the part (i.e. using the device code), and have the system software use the appropriate sector size for program operations. In this manner, the user can have a common board design for 256K to 4-megabit densities and, with each density’s sector size in a memory map, have the system software apply the appropriate sector size. For details, see Operating Modes (for hardware operation) or Software Product Identification. The manufacturer and device code is the same for both methods of identification. 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 A9 (including NC Pins) with Respect to Ground ................... -0.6V to +13.5V DATA POLLING: The AT29BV020 features DATA polling to indicate the end of a program cycle. During a program cycle an attempted read of the last byte loaded will result in the complement of the loaded data on I/O7. Once the program cycle has been completed, true data is valid on all outputs and the next cycle may begin. DATA polling may begin at any time during the program cycle. TOGGLE BIT: I n a d d i t i o n t o DATA p o l l i n g t h e AT29BV020 provides another method for determining the end of a program or erase cycle. During a program or erase operation, successive attempts to read data from the device will result in I/O6 toggling between one and zero. Once the program cycle has completed, I/O6 will stop toggling and valid data will be read. Examining the toggle bit may begin at any time during a program cycle. OPTIONAL CHIP ERASE MODES: The entire device may be erased by using a 6-byte software code. Please see Software Chip Erase application note for details. BOOT BLOCK PROGRAMMING LOCKOUT: The AT29BV020 has two designated memory blocks that have a programming lockout feature. This feature prevents programming of data in the designated block once the feature has been enabled. Each of these blocks consists of 8K bytes; the programming lockout feature can be set independently for either block. While the lockout feature does not have to be activated, it can be activated for either or both blocks. These two 8K memory sections are referred to as boot blocks. Secure code which will bring up a system can be contained in a boot block. The AT29BV020 blocks are located in the first 8K bytes of memory and the last 8K bytes of memory. The boot block programming lockout feature can therefore support systems that boot from the lower addresses of memory or the higher addresses. Once the programming lockout feature has been activated, the data in that block can no longer be erased or programmed; data in other memory locations can still be changed through the regular programming methods. To activate the lockout feature, a series of seven program commands to specific addresses with specific data must be performed. Please see Boot Block Lockout Feature Enable Algorithm. If the boot block lockout feature has been activated on either block, the chip erase function will be disabled. (continued) *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. 4-15 Device Operation (Continued) BOOT BLOCK LOCKOUT DETECTION: A software method is available to determine whether programming of either boot block section is locked out. See Software Product Identification Entry and Exit sections. When the device is in the software product identification mode, a read from location 00002H will show if programming the lower address boot block is locked out while reading location FFFF2H will do so for the upper boot block. If the data is FE, the corresponding block can be programmed; if the data is FF, the program lockout feature has been activated and the corresponding block cannot be programmed. The software product identification exit mode should be used to return to standard operation. DC and AC Operating Range Operating Temperature (Case) VCC Power Supply Com. Ind. (1) AT29BV020-25 AT29BV020-35 0°C - 70°C 0°C - 70°C -40°C - 85°C -40°C - 85°C 2.7V to 3.6V 2.7V to 3.6V 1. After power is applied and VCC is at the minimum specified data sheet value, the system should wait 20 ms before an operational mode is started. Operating Modes Mode Read CE OE WE Ai I/O DOUT VIL VIL VIH Ai (2) VIL VIH VIL Ai DIN Standby/Write Inhibit VIH X (1) X X High Z X X VIH Program Program Inhibit Program Inhibit X VIL X Output Disable X VIH X High Z Product Identification Hardware VIL VIL A1 - A17 = VIL, A9 = VH (3), A0 = VIL A1 - A17 = VIL, A9 = VH (3), A0 = VIH VIH Software (5) Notes: 1. X can be VIL or VIH. 2. Refer to AC Programming Waveforms. 3. VH = 12.0V ± 0.5V. Manufacturer Code (4) Device Code (4) A0 = VIL, A1 - A17 = VIL Manufacturer Code (4) A0 = VIH, A1 - A17 = VIL Device Code (4) 4. Manufacturer Code is 1F. The Device Code is BA. 5. See details under Software Product Identification Entry/Exit. DC Characteristics Symbol Parameter Condition ILI Input Load Current VIN = 0V to VCC ILO Output Leakage Current VI/O = 0V to VCC Min 1 µA 1 µA 20 µA Ind. 50 µA 1 mA 15 mA 0.6 V VCC Standby Current CMOS CE = VCC - 0.3V to VCC ISB2 VCC Standby Current TTL CE = 2.0V to VCC ICC VCC Active Current f = 5 MHz; IOUT = 0 mA; VCC = 3.6V VIL Input Low Voltage VIH Input High Voltage VOL Output Low Voltage IOL = 1.6 mA; VCC = 3.0V VOH Output High Voltage IOH = -100 µA; VCC = 3.0V AT29BV020 Units Com. ISB1 4-16 Max 2.0 V 0.45 2.4 V V AT29BV020 AC Read Characteristics AT29BV020-25 Max Units 250 350 ns 250 350 ns 0 150 ns 0 75 ns Symbol Parameter tACC Address to Output Delay tCE (1) CE to Output Delay tOE (2) OE to Output Delay 0 120 tDF (3, 4) CE or OE to Output Float 0 60 tOH Output Hold from OE, CE or Address, whichever occurred first 0 Min AT29BV020-35 Max Min 0 ns AC Read Waveforms 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 < 5 ns Pin Capacitance (f = 1 MHz, T = 25°C) (1) CIN COUT Note: Typ Max Units Conditions 4 6 pF VIN = 0V 8 12 pF VOUT = 0V 1. These parameters are characterized and not 100% tested. 4-17 AC Byte Load Characteristics Symbol Parameter Min tAS, tOES Address, OE Set-up Time 10 ns tAH Address Hold Time 100 ns tCS Chip Select Set-up Time 0 ns tCH Chip Select Hold Time 0 ns tWP Write Pulse Width (WE or CE) 200 ns tDS Data Set-up Time 100 ns tDH, tOEH Data, OE Hold Time 10 ns tWPH Write Pulse Width High 200 ns AC Byte Load Waveforms (1, 2) WE Controlled CE Controlled 4-18 AT29BV020 Max Units AT29BV020 Program Cycle Characteristics Symbol Parameter Min Max Units tWC Write Cycle Time 20 ms tAS Address Set-up Time 10 ns tAH Address Hold Time 100 ns tDS Data Set-up Time 100 ns tDH Data Hold Time 10 ns tWP Write Pulse Width 200 ns tBLC Byte Load Cycle Time tWPH Write Pulse Width High 150 200 µs ns Software Protected Program Waveform Notes: 1. OE must be high when WE and CE are both low. 2. A8 through A17 must specify the sector address during each high to low transition of WE (or CE) after the software code has been entered. Programming Algorithm 3. Data in bytes not loaded within a sector being programmed may be altered by the program operation; therefore, all bytes within a sector must be loaded. (1) LOAD DATA AA TO ADDRESS 5555 LOAD DATA 55 TO ADDRESS 2AAA LOAD DATA A0 TO ADDRESS 5555 LOAD DATA TO (3) SECTOR (256 BYTES) WRITES ENABLED ENTER DATA PROTECT STATE (2) Notes for software program code: 1. Data Format: I/O7 - I/O0 (Hex); Address Format: A14 - A0 (Hex). 2. Data Protect state will be re-activated at end of program cycle. 3. 256-bytes of data MUST BE loaded. 4-19 Data Polling Characteristics (1, 2) Symbol Parameter Min Typ Max tDH Data Hold Time 10 ns tOEH OE Hold Time 10 ns Delay (2) tOE OE to Output tWR Write Recovery Time Units ns 0 ns Notes: 1. These parameters are characterized and not 100% tested. 2. See tOE spec in AC Read Characteristics. Data Polling Waveforms Toggle Bit Characteristics Symbol Parameter tDH Data Hold Time tOEH OE Hold Time (1) Min Typ OE to Output Delay tOEHP OE High Pulse tWR Write Recovery Time Units 10 ns 10 ns (2) tOE Max ns 150 ns 0 ns Notes: 1. These parameters are characterized and not 100% tested. 2. See tOE spec in AC Read Characteristics. Toggle Bit Waveforms (1, 3) Notes: 1. Toggling either OE or CE or both OE and CE will operate toggle bit. 4-20 AT29BV020 2. Beginning and ending state of I/O6 will vary. 3. Any address location may be used but the address should not vary. AT29BV020 Boot Block Lockout (1) Feature Enable Algorithm Software Product (1) Identification Entry LOAD DATA AA TO ADDRESS 5555 LOAD DATA AA TO ADDRESS 5555 LOAD DATA 55 TO ADDRESS 2AAA LOAD DATA 55 TO ADDRESS 2AAA LOAD DATA 90 TO ADDRESS 5555 LOAD DATA 80 TO ADDRESS 5555 PAUSE 20 mS LOAD DATA AA TO ADDRESS 5555 ENTER PRODUCT IDENTIFICATION (2, 3) MODE LOAD DATA 55 TO ADDRESS 2AAA Software Product (1) Identification Exit LOAD DATA 40 TO ADDRESS 5555 LOAD DATA AA TO ADDRESS 5555 LOAD DATA 55 TO ADDRESS 2AAA LOAD DATA F0 TO ADDRESS 5555 PAUSE 20 mS EXIT PRODUCT IDENTIFICATION (4) MODE LOAD DATA 00 TO ADDRESS 00000H (2) LOAD DATA FF TO ADDRESS FFFFFH (3) PAUSE 20 mS PAUSE 20 mS Notes for boot block lockout feature enable: 1. Data Format: I/O7 - I/O0 (Hex); Address Format: A14 - A0 (Hex). 2. Lockout feature set on lower address boot block. 3. Lockout feature set on higher address boot block. Notes for software product identification: 1. Data Format: I/O7 - I/O0 (Hex); Address Format: A14 - A0 (Hex). 2. A1 - A17 = VIL. Manufacture Code is read for A0 = VIL; Device Code is read for A0 = VIH. 3. The device does not remain in identification mode if powered down. 4. The device returns to standard operation mode. 5. Manufacturer Code is 1F. The Device Code is BA. 4-21 Ordering Information tACC ICC (mA) Ordering Code Package 0.02 AT29BV020-25JC AT29BV020-25TC 32J 32T Commercial (0° to 70°C) 15 0.05 AT29BV020-25JI AT29BV020-25TI 32J 32T Industrial (-40° to 85°C) 15 0.02 AT29BV020-35JC AT29BV020-35TC 32J 32T Commercial (0° to 70°C) 15 0.05 AT29BV020-35JI AT29BV020-35TI 32J 32T Industrial (-40° to 85°C) (ns) Active Standby 250 15 350 Package Type 32J 32 Lead, Plastic J-Leaded Chip Carrier (PLCC) 32T 32 Lead, Thin Small Outline Package (TSOP) 4-22 AT29BV020 Operation Range