AT49F040B Datasheet, PDF (1/19 Pages) ATMEL Corporation – 4-megabit (512K x 8) 5-volt Only Flash Memory

Features
• Single Supply for Read and Write: 4.5 to 5.5V
• Fast Read Access Time – 55 ns
• Internal Program Control and Timer
• Flexible Sector Architecture
– One 16K Bytes Boot Sector with Programming Lockout
– Two 8K Bytes Parameter Sectors
– Eight Main Memory Sectors (One 32K Bytes, Seven 64K Bytes)
• Fast Erase Cycle Time – 8 Seconds
• Byte-by-Byte Programming – 12 µs/Byte Typical
• Hardware Data Protection
• DATA Polling or Toggle Bit for End of Program Detection
• Low Power Dissipation
– 20 mA Active Current
– 25 µA CMOS Standby Current
• Minimum 100,000 Write Cycles
4-megabit
(512K x 8)
5-volt Only
Flash Memory
1. Description
The AT49F040B is a 5-volt-only in-system reprogrammable Flash Memory. Its
4 megabits of memory is organized as 524,288 words by 8 bits. Manufactured with
Atmel’s advanced nonvolatile CMOS technology, the device offers access times to
55 ns with power dissipation of just 110 mW over the commercial temperature range.
When the device is deselected, the CMOS standby current is less than 25 µA. To
allow for simple in-system reprogrammability, the AT49F040B does not require high
input voltages for programming. Five-volt-only commands determine the read and
programming operation of the device. Reading data out of the device is similar to
reading from an EPROM; it has standard CE, OE, and WE inputs to avoid bus conten-
tion. Reprogramming the AT49F040B is performed by erasing a sector of data and
then programming on a byte by byte basis. The byte programming time is a fast 12 µs.
The end of a program or erase cycle can be optionally detected by the DATA polling
or toggle bit feature. Once the end of a byte program cycle has been detected, a new
access for a read or program can begin. The typical number of program and erase
cycles is in excess of 100,000 cycles.
The device is erased by executing a chip erase or a sector erase command sequence;
the device internally controls the erase operations. The memory array of the
AT49F040B is organized into two 8K byte parameter sectors, eight main memory sec-
tors, and one boot sector.
The device has the capability to protect the data in the boot sector; this feature is
enabled by a command sequence. The 16K-byte boot sector includes a reprogram-
ming lock out feature to provide data integrity. The boot sector is designed to contain
user secure code, and when the feature is enabled, the boot sector is permanently
protected from being reprogrammed.
AT49F040B
3606A–FLASH–12/05