AT49F040A ATMEL Corporation, AT49F040A Datasheet - Page 2

• Manufacturer Part Number: AT49F040A
• Description: 4-megabit (512K x 8) 5-volt Only Flash Memory
• Manufacturer: ATMEL Corporation

Block Diagram
2
AT49F040A
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 contention. Reprogramming the AT49F040A is per-
formed 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 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 10,000 cycles.
The device is erased by executing the erase command sequence; the device internally con-
trols 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 reprogramming lock out fea-
ture 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.
ADDRESS
INPUTS
RESET
GND
VCC
WE
OE
CE
Y DECODER
X DECODER
CONTROL
LOGIC
DATA INPUTS/OUTPUTS
DATA LATCHES
INPUT/OUTPUT
MAIN MEMORY
MAIN MEMORY
MAIN MEMORY
MAIN MEMORY
MAIN MEMORY
MAIN MEMORY
MAIN MEMORY
MAIN MEMORY
BOOT BLOCK
PARAMETER
PARAMETER
(64K BYTES)
(64K BYTES)
(64K BYTES)
(64K BYTES)
(64K BYTES)
(64K BYTES)
(64K BYTES)
(32K BYTES)
(16K BYTES)
(8K BYTES)
(8K BYTES)
AT49F040A
PROGRAM
Y-GATING
I/O7 - I/O0
BUFFERS
BLOCK 8
BLOCK 7
BLOCK 6
BLOCK 5
BLOCK 4
BLOCK 3
BLOCK 2
BLOCK 1
BLOCK 2
BLOCK 1
8
7FFFF
70000
6FFFF
60000
5FFFF
50000
4FFFF
40000
3FFFF
30000
2FFFF
20000
1FFFF
10000
0FFFF
08000
07FFF
06000
05FFF
04000
03FFF
00000
3359B–FLASH–10/04