Features
•
Single Voltage Operation
– 5V Read
– 5V Reprogramming
Fast Read Access Time – 55 ns
Internal Program Control and Timer
8K Bytes Boot Block With Lockout
Fast Erase Cycle Time – 10 Seconds
Byte-by-byte Programming – 10 µs/Byte
Hardware Data Protection
DATA Polling For End of Program Detection
Low Power Dissipation
– 30 mA Active Current
– 100 µA CMOS Standby Current
Typical 10,000 Write Cycles
Green (Pb/Halide-free) Packaging Option
•
•
•
•
•
•
•
•
512K (64K x 8)
5-volt Only
Flash Memory
AT49F512
•
•
1. Description
The AT49F512 is a 5-volt-only in-system programmable and erasable Flash memory.
Its 512K of memory is organized as 65,536 words by 8 bits. Manufactured with
Atmel’s advanced nonvolatile CMOS technology, the devices offer access times to
55 ns with a power dissipation of just 165 mW over the commercial temperature
range. When the device is deselected, the CMOS standby current is less than 100 µA.
To allow for simple in-system reprogrammability, the AT49F512 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. Reprogramming the AT49F512 is performed by erasing the
entire 512K of memory and then programming on a byte-by-byte basis. The typical
byte programming time is a fast 10 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 pro-
gram and erase cycles is in excess of 10,000 cycles.
The optional 8K bytes boot block section includes a reprogramming write 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.
1027F–FLASH–3/05
2. Pin Configurations
Pin Name
A0 - A15
CE
OE
WE
I/O0 - I/O7
NC
Function
Addresses
Chip Enable
Output Enable
Write Enable
Data Inputs/Outputs
No Connect
2.1
32-lead PLCC Top View
A12
A15
NC
NC
VCC
WE
NC
2.2
32-lead VSOP Top View (8 x 14 mm) or 32-lead TSOP (Type 1)Top View (8 x 20 mm)
I/O1
I/O2
GND
I/O3
I/O4
I/O5
I/O6
14
15
16
17
18
19
20
A7
A6
A5
A4
A3
A2
A1
A0
I/O0
5
6
7
8
9
10
11
12
13
4
3
2
1
32
31
30
29
28
27
26
25
24
23
22
21
A14
A13
A8
A9
A11
OE
A10
CE
I/O7
A11
A9
A8
A13
A14
NC
WE
VCC
NC
NC
A15
A12
A7
A6
A5
A4
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
32
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
OE
A10
CE
I/O7
I/O6
I/O5
I/O4
I/O3
GND
I/O2
I/O1
I/O0
A0
A1
A2
A3
2
AT49F512
1027F–FLASH–3/05
AT49F512
3. Block Diagram
FFFFH
2000H
1FFFH
0000H
4. Device Operation
4.1
Read
The AT49F512 is accessed like an EPROM. 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 whenever CE or OE is high. This dual-line control
gives designers flexibility in preventing bus contention.
4.2
Erasure
Before a byte can be reprogrammed, the 64K bytes memory array (or 56K bytes if the boot block
featured is used) must be erased. The erased state of the memory bits is a logical “1”. The entire
device can be erased at one time by using a 6-byte software code. The chip erase code consists
of 6-byte load commands to specific address locations with a specific data pattern (please refer
to the Chip Erase Cycle Waveforms).
After the chip erase has been initiated, the device will internally time the erase operation so that
no external clocks are required. The maximum time needed to erase the whole chip is t
EC
. If the
boot block lockout feature has been enabled, the data in the boot sector will not be erased.
4.3
Byte Programming
Once the memory array is erased, the device is programmed (to a logical “0”) on a byte-by-byte
basis. Please note that a data “0” cannot be programmed back to a “1”; only erase operations
can convert “0”s to “1”s. Programming is accomplished via the internal device command register
and is a 4 bus cycle operation (please refer to the Command Definitions table). The device will
automatically generate the required internal program pulses.
The program cycle has addresses latched on the falling edge of WE or CE, whichever occurs
last, and the data latched on the rising edge of WE or CE, whichever occurs first. Programming
is completed after the specified t
BP
cycle time. The DATA polling feature may also be used to
indicate the end of a program cycle.
3
1027F–FLASH–3/05
4.4
Boot Block Programming Lockout
The device has one designated block that has a programming lockout feature. This feature pre-
vents programming of data in the designated block once the feature has been enabled. The size
of the block is 8K bytes. This block, referred to as the boot block, can contain secure code that is
used to bring up the system. Enabling the lockout feature will allow the boot code to stay in the
device while data in the rest of the device is updated. This feature does not have to be activated;
the boot block’s usage as a write protected region is optional to the user. The address range of
the boot block is 0000H to 1FFFH.
Once the feature is enabled, the data in the boot block can no longer be erased or programmed.
Data in the main memory block can still be changed through the regular programming method.
To activate the lockout feature, a series of six program commands to specific addresses with
specific data must be performed. Please refer to the Command Definitions table.
4.4.1
Boot Block Lockout Detection
A software method is available to determine if programming of the boot block section is locked
out. When the device is in the software product identification mode (see Software Product Iden-
tification Entry and Exit sections) a read from address location 00002H will show if programming
the boot block is locked out. If the data on I/O0 is low, the boot block can be programmed; if the
data on I/O0 is high, the program lockout feature has been activated and the block cannot be
programmed. The software product identification code should be used to return to standard
operation.
4.5
Product Identification
The product identification mode identifies the device and manufacturer as Atmel. It may be
accessed by hardware or software operation. The hardware operation mode can be used by an
external programmer to identify the correct programming algorithm for the Atmel product.
For details, see Operating Modes (for hardware operation) or Software Product Identification.
The manufacturer and device code is the same for both modes.
4.6
DATA Polling
The AT49F512 features DATA polling to indicate the end of a program cycle. During a program
cycle an attempted read of the last byte loaded will result in the complement of the loaded data
on I/O7. Once the program cycle has been completed, true data is valid on all outputs and the
next cycle may begin. DATA polling may begin at any time during the program cycle.
4.7
Toggle Bit
In addition to DATA polling the AT49F512 provides another method for determining the end of a
program or erase cycle. During a program or erase operation, successive attempts to read data
from the device will result in I/O6 toggling between one and zero. Once the program cycle has
completed, I/O6 will stop toggling and valid data will be read. Examining the toggle bit may begin
at any time during a program cycle.
4.8
Hardware Data Protection
Hardware features protect against inadvertent programs to the AT49F512 in the following ways:
(a) V
CC
sense: if V
CC
is below 3.8V (typical), the program function is inhibited. (b) Program
inhibit: holding any one of OE low, CE high or WE high inhibits program cycles. (c) Noise filter:
Pulses of less than 15 ns (typical) on the WE or CE inputs will not initiate a program cycle.
4
AT49F512
1027F–FLASH–3/05
AT49F512
5. Command Definition Table
Command
Sequence
Read
Chip Erase
Byte Program
Boot Block
Lockout
(1)
Product ID
Entry
Product ID
Exit
(2)
Product ID
Exit
(2)
Notes:
Bus
Cycles
1
6
4
6
3
3
1
1st Bus
Cycle
Addr
Addr
5555
5555
5555
5555
5555
XXXX
Data
D
OUT
AA
AA
AA
AA
AA
F0
2AAA
2AAA
2AAA
2AAA
2AAA
55
55
55
55
55
5555
5555
5555
5555
5555
80
A0
80
90
F0
5555
Addr
5555
AA
D
IN
AA
2AAA
55
5555
40
2AAA
55
5555
10
2nd Bus
Cycle
Addr
Data
3rd Bus
Cycle
Addr
Data
4th Bus
Cycle
Addr
Data
5th Bus
Cycle
Addr
Data
6th Bus
Cycle
Addr
Data
1. The 8K byte boot sector has the address range 0000H to 1FFFH.
2. Either one of the Product ID exit commands can be used.
6. Absolute Maximum Ratings*
Temperature Under Bias................................ -55°C to +125°C
Storage Temperature ..................................... -65°C to +150°C
All Input Voltages
(including NC pins)
with Respect to Ground ...................................-0.6V to +6.25V
All Output Voltages
with Respect to Ground .............................-0.6V to V
CC
+ 0.6V
Voltage on OE
with Respect to Ground ...................................-0.6V to +13.5V
*NOTICE:
Stresses beyond those listed under “Absolute
Maximum Ratings” may cause permanent dam-
age 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.
5
1027F–FLASH–3/05
京公网安备 11010802033920号
EEWORLD
