AT28LV010
Features
∙Single 3.3V ± 10% Supply
∙Fast Read Access Time - 200 ns
∙Automatic Page Write Operation
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Internal Address and Data Latches for 128-Bytes |
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Internal Control Timer |
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Fast Write Cycle Time |
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Page Write Cycle Time - 10 ms Maximum |
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1 to 128-Byte Page Write Operation |
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Low Power Dissipation |
1 Megabit |
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15 mA Active Current |
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20 μA CMOS Standby Current |
(128K x 8) |
Hardware and Software Data Protection |
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DATA Polling for End of Write Detection |
Low Voltage |
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High Reliability CMOS Technology |
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Endurance: 100,000K Cycles |
Paged CMOS |
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Data Retention: 10 Years |
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JEDEC Approved Byte-Wide Pinout |
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Commercial and Industrial Temperature Ranges |
2 |
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E PROM |
Description
The AT28LV010 is a high-performance 3-volt only Electrically Erasable and Programmable Read Only Memory. Its 1 megabit of memory is organized as 131,072 words by 8 bits. Manufactured with Atmel’s advanced nonvolatile CMOS technology, the device offers access times to 200 ns with power dissipation of just 54 mW. When the device is deselected, the CMOS standby current is less than 20 μA.
Pin Configurations |
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Pin Name |
Function |
PDIP |
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A0 - A16 |
Addresses |
Top View |
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CE |
Chip Enable |
AT28LV010 |
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OE |
Output Enable |
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WE |
Write Enable |
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I/O0 - I/O7 |
Data |
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Inputs/Outputs |
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NC |
No Connect |
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DC |
Don’t Connect |
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PLCC |
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Top View |
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TSOP |
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Top View |
0395A
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Description (Continued)
The AT28LV010 is accessed like a Static RAM for the read or write cycle without the need for external components. The device contains a 128-byte page register to allow writing of up to 128-bytes simultaneously. During a write cycle, the address and 1 to 128-bytes of data are internally latched, freeing the address and data bus for other operations. Following the initiation of a write cycle, the device will automatically write the latched data using an internal control timer. The end of a write cycle can be detected by DATA polling of I/O7. Once the end of a write cycle has been detected a new access for a read or write can begin.
Atmel’s 28LV010 has additional features to ensure high quality and manufacturability. The device utilizes internal error correction for extended endurance and improved data retention characteristics. Software data protection is implemented to guard against inadvertent writes. The device also includes an extra 128-bytes of E2PROM for device identification or tracking.
Block Diagram
Absolute Maximum Ratings*
Temperature Under Bias |
................. -55°C to +125°C |
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Storage Temperature...................... |
-65°C to +150°C |
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All Input Voltages |
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(including NC Pins) |
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with Respect to Ground ................... |
-0.6V to +6.25V |
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All Output Voltages |
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with Respect to Ground ............. |
- 0.6V to VCC + 0.6V |
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Voltage on OE and A9 |
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with Respect to Ground ................... |
-0.6V to +13.5V |
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*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.
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Device Operation
READ: The AT28LV010 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 the high impedance state when either CE or OE is high. This dualline control gives designers flexibility in preventing bus contention in their system.
WRITE: The write operation of the AT28LV010 allows 1 to 128-bytes of data to be written into the device during a single internal programming period. Each write operation must be preceded by the software data protection (SDP) command sequence. This sequence is a series of three unique write command operations that enable the internal write circuitry. The command sequence and the data to be written must conform to the software protected write cycle timing. Addresses are latched on the falling edge of WE or CE, whichever occurs last and data is latched on the rising edge of WE or CE, whichever occurs first. Each successive byte must be written within 150 μs (tBLC) of the previous byte. If the tBLC limit is exceeded the AT28LV010 will cease accepting data and commence the interal programming operation. If more than one data byte is to be written during a single programming operation, they must reside on the same page as defined by the state of the A7 - A16 inputs. For each WE high to low transition during the page write operation, A7 - A16 must be the same.
The A0 to A6 inputs are used to specify which bytes within the page are to be written. The bytes may be loaded in any order and may be altered within the same load period. Only bytes which are specified for writing will be written; unnecessary cycling of other bytes within the page does not occur.
DATA POLLING: The AT28LV010 features DATA Polling to indicate the end of a write cycle. During a byte or page write cycle an attempted read of the last byte written will result in the complement of the written data to be presented on I/O7. Once the write cycle has been completed, true data is valid on all outputs, and the next write cycle may begin. DATA Polling may begin at anytime during the write cycle.
AT28LV010
TOGGLE BIT: In addition to DATA Polling the AT28LV010 provides another method for determining the end of a write cycle. During the write operation, successive attempts to read data from the device will result in I/O6 toggling between one and zero. Once the write has completed, I/O6 will stop toggling and valid data will be read. Reading the toggle bit may begin at any time during the write cycle.
DATA PROTECTION: If precautions are not taken, inadvertent writes may occur during transitions of the host system power supply. Atmel has incorporated both hardware and software features that will protect the memory against inadvertent writes.
HARDWARE PROTECTION: Hardware features protect against inadvertent writes to the AT28LV010 in the following ways: (a) VCC power-on delay - once VCC has reached 2.0V (typical) the device will automatically time out 5 ms (typical) before allowing a write: (b) write inhibit - holding any one of OE low, CE high or WE high inhibits write cycles; (c) noise filter - pulses of less than 15 ns (typical) on the WE or CE inputs will not initiate a write cycle.
SOFTWARE DATA PROTECTION: The AT28LV010 incorporates the industry standard software data protection (SDP) function. Unlike standard 5-volt only E2PROM’s, the AT28LV010 has SDP enabled at all times. Therefore, all write operations must be preceded by the SDP command sequence.
The data in the 3-byte command sequence is not written to the device; the addresses in the command sequence can be utilized just like any other location in the device. Any attempt to write to the device without the 3-byte sequence will start the internal timers. No data will be written to the device. However, for the duration of tWC, read operations will effectively be polling operations.
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