Features

– 5V Read

– 5V Reprogramming

– One 16K Bytes Boot Block with Programming Lockout

– Two 8K Bytes Parameter Blocks

– Eight Main Memory Blocks (One 32K Bytes, Seven 64K Bytes)

– 20 mA Active Current

– 70 µA CMOS Standby Current

1.

Description

The AT49F040A 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 70 µA. To

allow for simple in-system reprogrammability, the AT49F040A 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 AT49F040A is performed by erasing a block of data and

then programming on a byte-by-byte basis. The byte programming time is a fast 20

µs. The end of a program cycle can be optionally detected by the DATA polling fea-

ture. 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 10,000 cycles.

The device is erased by executing the erase command sequence; the device inter-

nally controls the erase operations. There are two 8K byte parameter block sections,

eight main memory blocks, and one boot block.

The device has the capability to protect the data in the boot block; this feature is

enabled by a command sequence. The 16K-byte boot block section includes a repro-

gramming 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 perma-

nently protected from being reprogrammed.

4-megabit

(512K x 8)

5-volt Only

Flash Memory

AT49F040A

3359C–FLASH–3/05