Features
• Fast Read Access Time – 70 ns
• 5-volt Only Reprogramming
• Sector Program Operation
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– Single Cycle Reprogram (Erase and Program)
– 1024 Sectors (256 Bytes/Sector)
– Internal Address and Data Latches for 256 Bytes
Internal Program Control and Timer
Hardware and Software Data Protection
Two 8K Bytes Boot Blocks with Lockout
Fast Sector Program Cycle Time – 10 ms
DATA Polling for End of Program Detection
Low Power Dissipation
– 40 mA Active Current
– 100 µA CMOS Standby Current
Typical Endurance > 10,000 Cycles
Single 5V ±10% Supply
CMOS and TTL Compatible Inputs and Outputs
Commercial and Industrial Temperature Ranges
Green (Pb/Halide-free) Packaging Option
2-megabit
(256K x 8)
5-volt Only
Flash Memory
AT29C020
1. Description
The AT29C020 is a 5-volt-only in-system Flash programmable and erasable read-only
memory (PEROM). Its 2 megabits of memory is organized as 262,144 bytes. Manufactured with Atmel’s advanced nonvolatile CMOS technology, the device offers
access times to 70 ns with power dissipation of just 220 mW over the commercial temperature range. When the device is deselected, the CMOS standby current is less
than 100 µA. Device endurance is such that any sector can typically be written to in
excess of 10,000 times.
To allow for simple in-system reprogrammability, the AT29C020 does not require high
input voltages for programming. Five-volt-only commands determine the operation of
the device. Reading data out of the device is similar to reading from an EPROM.
Reprogramming the AT29C020 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 256 bytes of data are 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.
0291Q–FLASH–11/05
