ATMEL AT29BV020-25TC 2 megabit 256k x 8 single 2.7-volt battery-voltage cmos flash memory Datasheet

AT29BV020
Features
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Single Supply Voltage, Range 2.7V to 3.6V
Single Supply for Read and Write
Software Protected Programming
Fast Read Access Time - 250 ns
Low Power Dissipation
15 mA Active Current
20 µA CMOS Standby Current
Sector Program Operation
Single Cycle Reprogram (Erase and Program)
1024 Sectors (256 bytes/sector)
Internal Address and Data Latches for 256-Bytes
Two 8 KB Boot Blocks with Lockout
Fast Sector Program Cycle Time - 20 ms Max.
Internal Program Control and Timer
DATA Polling for End of Program Detection
Typical Endurance > 10,000 Cycles
CMOS and TTL Compatible Inputs and Outputs
Commercial and Industrial Temperature Ranges
2 Megabit
(256K x 8)
Single 2.7-volt
Battery-Voltage
CMOS Flash
Memory
Description
The AT29BV020 is a 2.7-volt-only in-system Flash Programmable and Erasable Read
Only Memory (PEROM). Its 2 megabits of memory is organized as 262,144 words by
8 bits. Manufactured with Atmel’s advanced nonvolatile CMOS EEPROM technology,
the device offers access times up to 250 ns, and a low 54 mW power dissipation.
When the device is deselected, the CMOS standby current is less than 20 µA. The
device endurance is such that any sector can typically be written to in excess of
10,000 times. The programming algorithm is compatible with other devices in Atmel’s
Low Voltage Flash family of products.
(continued)
AT29BV020
Pin Configurations
Pin Name
Function
A0 - A17
Addresses
CE
Chip Enable
OE
Output Enable
WE
Write Enable
I/O0 - I/O7
Data Inputs/Outputs
NC
No Connect
TSOP Top View
PLCC Top View
Type 1
0402B
4-13
Description (Continued)
To allow for simple in-system reprogrammability, the
AT29BV020 does not require high input voltages for programming. The device can be operated with a single 2.7V
to 3.6V supply. Reading data out of the device is similar to
reading from an EPROM. Reprogramming the
AT29BV020 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 256bytes of data are captured at microprocessor speed and
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.
Block Diagram
Device Operation
READ: The AT29BV020 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 dualline control gives designers flexibility in preventing bus
contention.
will not reset the software data protection feature, however
the software feature will guard against inadvertent program cycles during power transitions.
SOFTWARE DATA PROTECTION PROGRAMMING:
The AT29BV020 has 1024 individual sectors, each 256bytes. Using the software data protection feature, byte
loads are used to enter the 256-bytes of a sector to be
programmed. The AT29BV020 can only be programmed
or reprogrammed using the software data protection feature. The device is programmed on a sector basis. If a byte
of data within the sector is to be changed, data for the entire 256-byte sector must be loaded into the device. The
data in any byte that is not loaded during the programming
of its sector will be indeterminate. The AT29BV020 automatically does a sector erase prior to loading the data into
the sector. An erase command is not required.
After the software data protection’s 3-byte command code
is given, a byte load is performed by applying a low pulse
on the WE or CE input with CE or WE low (respectively)
and OE high. The address is latched on the falling edge of
CE or WE, whichever occurs last. The data is latched by
the first rising edge of CE or WE.
Software data protection protects the device from inadvertent programming. A series of three program commands
to specific addresses with specific data must be presented
to the device before programming may occur. The same
three program commands must begin each program operation. All software program commands must obey the
sector program timing specifications. Power transitions
Any attempt to write to the device without the 3-byte command sequence will start the internal write timers. No data
will be written to the device; however, for the duration of
tWC, a read operation will effectively be a polling operation.
The 256-bytes of data must be loaded into each sector.
Any byte that is not loaded during the programming of its
sector will be indeterminate. Once the bytes of a sector
are loaded into the device, they are simultaneously programmed during the internal programming period. After
the first data byte has been loaded into the device, successive bytes are entered in the same manner. Each new
byte to be programmed must have its high to low transition
on WE (or CE) within 150 µs of the low to high transition of
WE (or CE) of the preceding byte. If a high to low transition
is not detected within 150 µs of the last low to high transition, the load period will end and the internal programming
period will start. A8 to A17 specify the sector address. The
(continued)
4-14
AT29BV020
AT29BV020
Device Operation (Continued)
sector address must be valid during each high to low transition of WE (or CE). A0 to A7 specify the byte address
within the sector. The bytes may be loaded in any order;
sequential loading is not required.
HARDWARE DATA PROTECTION: Hardware features
protect against inadvertent programs to the AT29BV020 in
the following ways: (a) VCC sense— if VCC is below 2.0V
(typical), the program function is inhibited. (b) VCC power
on delay— once VCC has reached the VCC sense level,
the device will automatically time out 10 ms (typical) before programming. (c) Program inhibit— holding any one
of OE low, CE high or WE high inhibits program cycles. (d)
Noise filter— pulses of less than 15 ns (typical) on the WE
or CE inputs will not initiate a program cycle.
INPUT LEVELS: While operating with a 2.7V to 3.6V
power supply, the address inputs and control inputs (OE,
CE and WE) may be driven from 0 to 5.5V without adversely affecting the operation of the device. The I/O lines
can only be driven from 0 to VCC + 0.6V.
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. In addition, users may wish
to use the software product identification mode to identify
the part (i.e. using the device code), and have the system
software use the appropriate sector size for program operations. In this manner, the user can have a common
board design for 256K to 4-megabit densities and, with
each density’s sector size in a memory map, have the system software apply the appropriate sector size.
For details, see Operating Modes (for hardware operation)
or Software Product Identification. The manufacturer and
device code is the same for both methods of identification.
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 VCC + 0.6V
Voltage on A9
(including NC Pins)
with Respect to Ground ................... -0.6V to +13.5V
DATA POLLING: The AT29BV020 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.
TOGGLE BIT: I n a d d i t i o n t o DATA p o l l i n g t h e
AT29BV020 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.
OPTIONAL CHIP ERASE MODES: The entire device
may be erased by using a 6-byte software code. Please
see Software Chip Erase application note for details.
BOOT BLOCK PROGRAMMING LOCKOUT: The
AT29BV020 has two designated memory blocks that have
a programming lockout feature. This feature prevents programming of data in the designated block once the feature
has been enabled. Each of these blocks consists of 8K
bytes; the programming lockout feature can be set independently for either block. While the lockout feature does
not have to be activated, it can be activated for either or
both blocks.
These two 8K memory sections are referred to as boot
blocks. Secure code which will bring up a system can be
contained in a boot block. The AT29BV020 blocks are located in the first 8K bytes of memory and the last 8K bytes
of memory. The boot block programming lockout feature
can therefore support systems that boot from the lower
addresses of memory or the higher addresses. Once the
programming lockout feature has been activated, the data
in that block can no longer be erased or programmed;
data in other memory locations can still be changed
through the regular programming methods. To activate the
lockout feature, a series of seven program commands to
specific addresses with specific data must be performed.
Please see Boot Block Lockout Feature Enable Algorithm.
If the boot block lockout feature has been activated on
either block, the chip erase function will be disabled.
(continued)
*NOTICE: Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage 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.
4-15
Device Operation (Continued)
BOOT BLOCK LOCKOUT DETECTION: A software
method is available to determine whether programming of
either boot block section is locked out. See Software Product Identification Entry and Exit sections. When the device
is in the software product identification mode, a read from
location 00002H will show if programming the lower address boot block is locked out while reading location
FFFF2H will do so for the upper boot block. If the data is
FE, the corresponding block can be programmed; if the
data is FF, the program lockout feature has been activated
and the corresponding block cannot be programmed. The
software product identification exit mode should be used
to return to standard operation.
DC and AC Operating Range
Operating
Temperature (Case)
VCC Power Supply
Com.
Ind.
(1)
AT29BV020-25
AT29BV020-35
0°C - 70°C
0°C - 70°C
-40°C - 85°C
-40°C - 85°C
2.7V to 3.6V
2.7V to 3.6V
1. After power is applied and VCC is at the minimum specified data sheet value, the system should wait 20 ms before an
operational mode is started.
Operating Modes
Mode
Read
CE
OE
WE
Ai
I/O
DOUT
VIL
VIL
VIH
Ai
(2)
VIL
VIH
VIL
Ai
DIN
Standby/Write Inhibit
VIH
X (1)
X
X
High Z
X
X
VIH
Program
Program Inhibit
Program Inhibit
X
VIL
X
Output Disable
X
VIH
X
High Z
Product Identification
Hardware
VIL
VIL
A1 - A17 = VIL, A9 = VH (3),
A0 = VIL
A1 - A17 = VIL, A9 = VH (3),
A0 = VIH
VIH
Software (5)
Notes: 1. X can be VIL or VIH.
2. Refer to AC Programming Waveforms.
3. VH = 12.0V ± 0.5V.
Manufacturer Code (4)
Device Code (4)
A0 = VIL, A1 - A17 = VIL
Manufacturer Code (4)
A0 = VIH, A1 - A17 = VIL
Device Code (4)
4. Manufacturer Code is 1F. The Device Code is BA.
5. See details under Software Product Identification Entry/Exit.
DC Characteristics
Symbol
Parameter
Condition
ILI
Input Load Current
VIN = 0V to VCC
ILO
Output Leakage Current
VI/O = 0V to VCC
Min
1
µA
1
µA
20
µA
Ind.
50
µA
1
mA
15
mA
0.6
V
VCC Standby Current CMOS
CE = VCC - 0.3V to VCC
ISB2
VCC Standby Current TTL
CE = 2.0V to VCC
ICC
VCC Active Current
f = 5 MHz; IOUT = 0 mA; VCC = 3.6V
VIL
Input Low Voltage
VIH
Input High Voltage
VOL
Output Low Voltage
IOL = 1.6 mA; VCC = 3.0V
VOH
Output High Voltage
IOH = -100 µA; VCC = 3.0V
AT29BV020
Units
Com.
ISB1
4-16
Max
2.0
V
0.45
2.4
V
V
AT29BV020
AC Read Characteristics
AT29BV020-25
Max
Units
250
350
ns
250
350
ns
0
150
ns
0
75
ns
Symbol
Parameter
tACC
Address to Output Delay
tCE (1)
CE to Output Delay
tOE (2)
OE to Output Delay
0
120
tDF (3, 4)
CE or OE to Output Float
0
60
tOH
Output Hold from OE, CE or Address,
whichever occurred first
0
Min
AT29BV020-35
Max
Min
0
ns
AC Read Waveforms
Notes: 1. CE may be delayed up to tACC - tCE after the address
transition without impact on tACC .
2. OE may be delayed up to tCE - tOE after the falling
edge of CE without impact on tCE or by tACC - tOE
after an address change without impact on tACC .
3. tDF is specified from OE or CE whichever occurs first
(CL = 5 pF).
4. This parameter is characterized and is not 100% tested.
Input Test Waveforms and Measurement Level
Output Test Load
tR, tF < 5 ns
Pin Capacitance (f = 1 MHz, T = 25°C) (1)
CIN
COUT
Note:
Typ
Max
Units
Conditions
4
6
pF
VIN = 0V
8
12
pF
VOUT = 0V
1. These parameters are characterized and not 100% tested.
4-17
AC Byte Load Characteristics
Symbol
Parameter
Min
tAS, tOES
Address, OE Set-up Time
10
ns
tAH
Address Hold Time
100
ns
tCS
Chip Select Set-up Time
0
ns
tCH
Chip Select Hold Time
0
ns
tWP
Write Pulse Width (WE or CE)
200
ns
tDS
Data Set-up Time
100
ns
tDH, tOEH
Data, OE Hold Time
10
ns
tWPH
Write Pulse Width High
200
ns
AC Byte Load Waveforms
(1, 2)
WE Controlled
CE Controlled
4-18
AT29BV020
Max
Units
AT29BV020
Program Cycle Characteristics
Symbol
Parameter
Min
Max
Units
tWC
Write Cycle Time
20
ms
tAS
Address Set-up Time
10
ns
tAH
Address Hold Time
100
ns
tDS
Data Set-up Time
100
ns
tDH
Data Hold Time
10
ns
tWP
Write Pulse Width
200
ns
tBLC
Byte Load Cycle Time
tWPH
Write Pulse Width High
150
200
µs
ns
Software Protected Program Waveform
Notes: 1. OE must be high when WE and CE are both low.
2. A8 through A17 must specify the sector address
during each high to low transition of WE (or CE)
after the software code has been entered.
Programming Algorithm
3. Data in bytes not loaded within a sector being programmed
may be altered by the program operation; therefore, all
bytes within a sector must be loaded.
(1)
LOAD DATA AA
TO
ADDRESS 5555
LOAD DATA 55
TO
ADDRESS 2AAA
LOAD DATA A0
TO
ADDRESS 5555
LOAD DATA
TO
(3)
SECTOR (256 BYTES)
WRITES ENABLED
ENTER DATA
PROTECT STATE
(2)
Notes for software program code:
1. Data Format: I/O7 - I/O0 (Hex);
Address Format: A14 - A0 (Hex).
2. Data Protect state will be re-activated at end of program cycle.
3. 256-bytes of data MUST BE loaded.
4-19
Data Polling Characteristics
(1, 2)
Symbol
Parameter
Min
Typ
Max
tDH
Data Hold Time
10
ns
tOEH
OE Hold Time
10
ns
Delay (2)
tOE
OE to Output
tWR
Write Recovery Time
Units
ns
0
ns
Notes: 1. These parameters are characterized and not 100% tested.
2. See tOE spec in AC Read Characteristics.
Data Polling Waveforms
Toggle Bit Characteristics
Symbol
Parameter
tDH
Data Hold Time
tOEH
OE Hold Time
(1)
Min
Typ
OE to Output Delay
tOEHP
OE High Pulse
tWR
Write Recovery Time
Units
10
ns
10
ns
(2)
tOE
Max
ns
150
ns
0
ns
Notes: 1. These parameters are characterized and not 100% tested.
2. See tOE spec in AC Read Characteristics.
Toggle Bit Waveforms
(1, 3)
Notes: 1. Toggling either OE or CE or both OE and CE will
operate toggle bit.
4-20
AT29BV020
2. Beginning and ending state of I/O6 will vary.
3. Any address location may be used but the address
should not vary.
AT29BV020
Boot Block Lockout
(1)
Feature Enable Algorithm
Software Product (1)
Identification Entry
LOAD DATA AA
TO
ADDRESS 5555
LOAD DATA AA
TO
ADDRESS 5555
LOAD DATA 55
TO
ADDRESS 2AAA
LOAD DATA 55
TO
ADDRESS 2AAA
LOAD DATA 90
TO
ADDRESS 5555
LOAD DATA 80
TO
ADDRESS 5555
PAUSE 20 mS
LOAD DATA AA
TO
ADDRESS 5555
ENTER PRODUCT
IDENTIFICATION
(2, 3)
MODE
LOAD DATA 55
TO
ADDRESS 2AAA
Software Product (1)
Identification Exit
LOAD DATA 40
TO
ADDRESS 5555
LOAD DATA AA
TO
ADDRESS 5555
LOAD DATA 55
TO
ADDRESS 2AAA
LOAD DATA F0
TO
ADDRESS 5555
PAUSE 20 mS
EXIT PRODUCT
IDENTIFICATION
(4)
MODE
LOAD DATA 00
TO
ADDRESS 00000H (2)
LOAD DATA FF
TO
ADDRESS FFFFFH (3)
PAUSE 20 mS
PAUSE 20 mS
Notes for boot block lockout feature enable:
1. Data Format: I/O7 - I/O0 (Hex);
Address Format: A14 - A0 (Hex).
2. Lockout feature set on lower address boot block.
3. Lockout feature set on higher address boot block.
Notes for software product identification:
1. Data Format: I/O7 - I/O0 (Hex);
Address Format: A14 - A0 (Hex).
2. A1 - A17 = VIL.
Manufacture Code is read for A0 = VIL;
Device Code is read for A0 = VIH.
3. The device does not remain in identification mode if
powered down.
4. The device returns to standard operation mode.
5. Manufacturer Code is 1F. The Device Code is BA.
4-21
Ordering Information
tACC
ICC (mA)
Ordering Code
Package
0.02
AT29BV020-25JC
AT29BV020-25TC
32J
32T
Commercial
(0° to 70°C)
15
0.05
AT29BV020-25JI
AT29BV020-25TI
32J
32T
Industrial
(-40° to 85°C)
15
0.02
AT29BV020-35JC
AT29BV020-35TC
32J
32T
Commercial
(0° to 70°C)
15
0.05
AT29BV020-35JI
AT29BV020-35TI
32J
32T
Industrial
(-40° to 85°C)
(ns)
Active
Standby
250
15
350
Package Type
32J
32 Lead, Plastic J-Leaded Chip Carrier (PLCC)
32T
32 Lead, Thin Small Outline Package (TSOP)
4-22
AT29BV020
Operation Range
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