ATMEL AT29C020

Features
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Fast Read Access Time - 90 ns
5-Volt-Only Reprogramming
Sector Program Operation
Single Cycle Reprogram (Erase and Program)
1024 Sectors (256 bytes/sector)
Internal Address and Data Latches for 256-Bytes
Internal Program Control and Timer
Hardware and Software Data Protection
Two 8 KB Boot Blocks with Lockout
Fast Sector Program Cycle Time - 10 ms
DATA Polling for End of Program Detection
Low Power Dissipation
40 mA Active Current
100 µA CMOS Standby Current
Typical Endurance > 10,000 Cycles
Single 5V ±10% Supply
CMOS and TTL Compatible Inputs and Outputs
Commercial and Industrial Temperature Ranges
2-Megabit
(256K x 8)
5-volt Only
CMOS Flash
Memory
Description
The AT29C020 is a 5-volt-only in-system Flash programmable and erasable read only
memory (PEROM). Its 2 megabits of memory is organized as 262,144 bytes. Manufactured with Atmel’s advanced nonvolatile CMOS technology, the device offers access times to 90 ns with power dissipation of just 220 mW over the commercial temperature range. When the device is deselected, the CMOS standby current is less
than 100 µA. Device endurance is such that any sector can typically be written to in
excess of 10,000 times.
(continued)
DIP Top View
AT29C020
AT29C020
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
PLCC Top View
TSOP Top View
Type 1
0291I/G20-I–6/97
Description (Continued)
To allow for simple in-system reprogrammability, the
AT29C020 does not require high input voltages for programming. Five-volt-only commands determine the operation of the device. Reading data out of the device is similar
to reading from an EPROM. Reprogramming the
AT29C020 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 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 AT29C020 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.
period will start. A8 to A17 specify the sector address. The
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. Once a programming
operation has been initiated, and for the duration of tWC, a
read operation will effectively be a polling operation.
BYTE LOAD: Byte loads are used to enter the 256bytes of a sector to be programmed or the software codes
for data protection. 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: A software controlled data protection feature is available on the AT29C020.
Once the software protection is enabled a software algorithm must be issued to the device before a program may
be performed. The software protection feature may be enabled or disabled by the user; when shipped from Atmel,
the software data protection feature is disabled. To enable
the software data protection, a series of three program
commands to specific addresses with specific data must
be performed. After the software data protection is enabled the same three program commands must begin
each program cycle in order for the programs to occur. All
software program commands must obey the sector program timing specifications. Once set, the software data
protection feature remains active unless its disable command is issued. Power transitions will not reset the software data protection feature, however the software feature will guard against inadvertent program cycles during
power transitions.
PROGRAM: The device is reprogrammed on a sector
basis. If a byte of data within a sector is to be changed,
data for the entire sector must be loaded into the device.
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
After setting SDP, any attempt to write to the device without the 3-byte command sequence will start the internal
(continued)
2
AT29C020
AT29C020
Device Operation (Continued)
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 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.
After the software data protection’s 3-byte command code
is given, a sector of data is loaded into the device using the
sector program timing specifications.
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
AT29C020 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.
HARDWARE DATA PROTECTION: Hardware features
protect against inadvertent programs to the AT29C020 in
the following ways: (a) VCC sense— if VCC is below 3.8V
(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 5 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.
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 modes.
DATA POLLING: The AT29C020 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
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
OPTIONAL CHIP ERASE MODE: The entire device
can be erased by using a 6-byte software code. Please
see Software Chip Erase application note for details.
BOOT BLOCK PROGRAMMING LOCKOUT: The
AT29C020 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 AT29C020 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.
BOOT BLOCK LOCKOUT DETECTION: A software
method is available to determine whether programming of
(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.
3
Device Operation (Continued)
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
AT29C020-90
AT29C020-10
AT29C020-12
AT29C020-15
0°C - 70°C
0°C - 70°C
0°C - 70°C
0°C - 70°C
-40°C - 85°C
-40°C - 85°C
-40°C - 85°C
5V ± 10%
5V ± 10%
5V ± 10%
Com.
Operating
Temperature (Case)
Ind.
5V ± 10%
VCC Power Supply
Operating Modes
CE
OE
WE
Ai
I/O
VIL
VIL
VIH
Ai
DOUT
VIL
VIH
VIL
Ai
DIN
5V Chip Erase
VIL
VIH
VIL
Ai
Standby/Write Inhibit
VIH
X (1)
X
X
Program Inhibit
X
X
VIH
Program Inhibit
X
VIL
X
Output Disable
X
VIH
X
Mode
Read
Program
(2)
High Z
High Z
Product Identification
Hardware
VIL
VIL
A1 - A17 = VIL, A9 = VH, (3)
A0 = VIL
A1 - A17 = VIL, A9 = VH,
A0 = VIH
A0 = VIL
VIH
Software (5)
Device Code (4)
Manufacturer Code (4)
Device Code (4)
A0 = VIH
Notes: 1. X can be VIL or VIH.
2. Refer to AC Programming Waveforms.
3. VH = 12.0V ± 0.5V.
Manufacturer Code (4)
4. Manufacturer Code: 1F, Device Code: DA
5. See details under Software Product Identification Entry/Exit.
DC Characteristics
Symbol
4
Max
Units
ILI
Input Load Current
Parameter
VIN = 0V to VCC
10
µA
ILO
Output Leakage Current
VI/O = 0V to VCC
10
µA
ISB1
VCC Standby Current CMOS
CE = VCC - 0.3V to VCC
Com.
100
µA
Ind.
300
ISB2
VCC Standby Current TTL
CE = 2.0V to VCC
3
µA
mA
ICC
VCC Active Current
f = 5 MHz; IOUT = 0 mA
40
mA
VIL
Input Low Voltage
0.8
V
VIH
Input High Voltage
VOL
Output Low Voltage
IOL = 2.1 mA
VOH1
Output High Voltage
IOH = -400 µA
2.4
V
VOH2
Output High Voltage CMOS
IOH = -100 µA; VCC = 4.5V
4.2
V
AT29C020
Condition
Min
2.0
V
.45
V
AT29C020
AC Read Characteristics
AT29C020-90
Symbol
Parameter
tACC
Address to Output Delay
AT29C020-10
Min
Max
Min
Max
0
90
100
90
100
AT29C020-12
Min
AT29C020-15
Max
Units
120
150
ns
120
150
ns
Max
Min
tCE
(1)
CE to Output Delay
tOE
(2)
OE to Output Delay
0
40
0
50
0
50
0
70
ns
tDF
(3, 4)
CE or OE to Output Float
0
25
0
25
0
30
0
40
ns
Output Hold from OE, CE or
Address, whichever
occurred first
0
tOH
0
0
0
ns
AC Read Waveforms (1, 2, 3, 4)
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
Note: While CE is active, any address inputs that cause VIH to drop
below 2.0V or VIL to rise above 0.8V for a duration of up to 15 ns
may cause the device to read incorrectly.
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. This parameter is characterized and is not 100% tested.
5
AC Byte Load Characteristics
Symbol
Parameter
tAS, tOES
Address, OE Set-up Time
0
ns
tAH
Address Hold Time
50
ns
tCS
Chip Select Set-up Time
0
ns
tCH
Chip Select Hold Time
0
ns
tWP
Write Pulse Width (WE or CE)
90
ns
tDS
Data Set-up Time
50
ns
tDH, tOEH
Data, OE Hold Time
0
ns
tWPH
Write Pulse Width High
100
ns
AC Byte Load Waveforms
WE Controlled
CE Controlled
6
AT29C020
Min
Max
Units
AT29C020
Program Cycle Characteristics
Symbol
Parameter
Min
Max
Units
tWC
Write Cycle Time
10
ms
tAS
Address Set-up Time
0
ns
tAH
Address Hold Time
50
ns
tDS
Data Set-up Time
50
ns
tDH
Data Hold Time
0
ns
tWP
Write Pulse Width
90
ns
tBLC
Byte Load Cycle Time
tWPH
Write Pulse Width High
150
100
µs
ns
Program Cycle Waveforms (1, 2, 3)
Notes: 1. A8 through A17 must specify the sector address
during each high to low transition of WE (or CE).
2. OE must be high when WE and CE are both low.
3. All bytes that are not loaded within the sector being
programmed will be indeterminate.
7
Software Data
(1)
Protection Enable Algorithm
Software Data
(1)
Protection Disable Algorithm
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 A0
TO
ADDRESS 5555
LOAD DATA 80
TO
ADDRESS 5555
LOAD DATA
TO
(4)
SECTOR (256 BYTES)
WRITES ENABLED
LOAD DATA AA
TO
ADDRESS 5555
ENTER DATA
(2)
PROTECT STATE
Notes for software program code:
1. Data Format: I/O7 - I/O0 (Hex);
Address Format: A14 - A0 (Hex).
2. Data Protect state will be activated at end of program cycle.
3. Data Protect state will be deactivated at end of program
period.
4. 256-bytes of data MUST BE loaded.
LOAD DATA 55
TO
ADDRESS 2AAA
LOAD DATA 20
TO
ADDRESS 5555
EXIT DATA
(3)
PROTECT STATE
LOAD DATA
TO
(4)
SECTOR (256 BYTES)
Software Protected Program Cycle Waveform (1, 2, 3)
Notes: 1. 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.
2. OE must be high when WE and CE are both low.
8
AT29C020
3. All bytes that are not loaded within the sector being
programmed will be indeterminate.
AT29C020
Data Polling Characteristics
Symbol
Parameter
tDH
Data Hold Time
tOEH
OE Hold Time
(1)
Min
Typ
Max
10
ns
10
ns
(2)
tOE
OE to Output Delay
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, 2, 3)
Notes: 1. Toggling either OE or CE or both OE and CE will
operate toggle bit.
2. Beginning and ending state of I/O6 will vary.
3. Any address location may be used but the address
should not vary.
9
Software Product (1)
Identification Entry
Boot Block Lockout
(1)
Feature Enable Algorithm
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 10 mS
LOAD DATA AA
TO
ADDRESS 5555
ENTER PRODUCT
IDENTIFICATION
MODE (2, 3, 5)
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 10 mS
EXIT PRODUCT
IDENTIFICATION
(4)
MODE
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: 1F
Device Code: DA
10
AT29C020
LOAD DATA 00
TO
ADDRESS 00000H (2)
LOAD DATA FF
TO
ADDRESS FFFFFH (3)
PAUSE 10 mS
PAUSE 10 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.
AT29C020
Ordering Information
ICC (mA)
tACC
(ns)
Active
Standby
90
40
100
120
150
Ordering Code
Package
Operation Range
0.1
AT29C020-90JC
AT29C020-90PC
AT29C020-90TC
32J
32P6
32T
Commercial
(0° to 70°C)
40
0.1
AT29C020-10JC
AT29C020-10PC
AT29C020-10TC
32J
32P6
32T
Commercial
(0° to 70°C)
40
0.3
AT29C020-10JI
AT29C020-10PI
AT29C020-10TI
32J
32P6
32T
Industrial
(-40° to 85°C)
40
0.1
AT29C020-12JC
AT29C020-12PC
AT29C020-12TC
32J
32P6
32T
Commercial
(0° to 70°C)
40
0.3
AT29C020-12JI
AT29C020-12PI
AT29C020-12TI
32J
32P6
32T
Industrial
(-40° to 85°C)
40
0.1
AT29C020-15JC
AT29C020-15PC
AT29C020-15TC
32J
32P6
32T
Commercial
(0° to 70°C)
40
0.3
AT29C020-15JI
AT29C020-15PI
AT29C020-15TI
32J
32P6
32T
Industrial
(-40° to 85°C)
Package Type
32J
32 Lead, Plastic J-Leaded Chip Carrier (PLCC)
32P6
32 Lead, 0.600" Wide, Plastic Dual Inline Package (PDIP)
32T
32 Lead, Thin Small Outline Package (TSOP)
11