2 Mbit / 4 Mbit (x8) Small-Sector Flash
SST29SF020 / SST29SF040
SST29VF020 / SST29VF040
SST29SF/VF020 / 0402Mb / 4Mb (x8)
Byte-Program, Small-Sector flash memories
Data Sheet
FEATURES:
• Organized as 256K x8 / 512K x8
• Single Voltage Read and Write Operations
– 4.5-5.5V for SST29SF020/040
– 2.7-3.6V for SST29VF020/040
• Superior Reliability
– Endurance: 100,000 Cycles (typical)
– Greater than 100 years Data Retention
• Low Power Consumption:
– Active Current: 10 mA (typical)
– Standby Current:
30 µA (typical) for SST29SF020/040
1 µA (typical) for SST29VF020/040
• Sector-Erase Capability
– Uniform 128 Byte sectors
• Fast Read Access Time:
– 55 ns for SST29SF020/040
– 70 ns for SST29VF020/040
• Latched Address and Data
• Fast Erase and Byte-Program:
– Sector-Erase Time: 18 ms (typical)
– Chip-Erase Time: 70 ms (typical)
– Byte-Program Time: 14 µs (typical)
– Chip Rewrite Time:
4 seconds (typical) for SST29SF/VF020
8 seconds (typical) for SST29SF/VF040
• Automatic Write Timing
– Internal V
PP
Generation
• End-of-Write Detection
– Toggle Bit
– Data# Polling
• TTL I/O Compatibility for SST29SF020/040
• CMOS I/O Compatibility for SST29VF020/040
• JEDEC Standard
– Flash EEPROM Pinouts and command sets
• Packages Available
– 32-lead PLCC
– 32-lead TSOP (8mm x 14mm)
• All non-Pb (lead-free) devices are RoHS compliant
PRODUCT DESCRIPTION
The SST29SF020/040 and SST29VF020/040 are 256K
x8 / 512K x8 CMOS Small-Sector Flash (SSF) manufac-
tured with SST’s proprietary, high-performance CMOS
SuperFlash technology. The split-gate cell design and
thick-oxide tunneling injector attain better reliability and
manufacturability compared with alternate approaches.
The SST29SF020/040 devices write (Program or Erase)
with a 4.5-5.5V power supply. The SST29VF020/040
devices write (Program or Erase) with a 2.7-3.6V power
supply. These devices conform to JEDEC standard pin
assignments for x8 memories.
Featuring high performance Byte-Program, the
SST29SF020/040 and SST29VF020/040 devices pro-
vide a maximum Byte-Program time of 20 µsec. To protect
against inadvertent write, they have on-chip hardware and
Software Data Protection schemes. Designed, manufac-
tured, and tested for a wide spectrum of applications, these
devices are offered with a guaranteed endurance of at least
10,000 cycles. Data retention is rated at greater than 100
years.
The SST29SF020/040 and SST29VF020/040 devices
are suited for applications that require convenient and eco-
nomical updating of program, configuration, or data mem-
©2009 Silicon Storage Technology, Inc.
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1
ory. For all system applications, they significantly improve
performance and reliability, while lowering power consump-
tion. They inherently use less energy during Erase and
Program than alternative flash technologies. The total
energy consumed is a function of the applied voltage, cur-
rent, and time of application. Since for any given voltage
range, the SuperFlash technology uses less current to pro-
gram and has a shorter erase time, the total energy con-
sumed during any Erase or Program operation is less than
alternative flash technologies. They also improve flexibility
while lowering the cost for program, data, and configuration
storage applications.
The SuperFlash technology provides fixed Erase and Pro-
gram times independent of the number of Erase/Program
cycles that have occurred. Therefore, the system software
or hardware does not have to be modified or de-rated as is
necessary with alternative flash technologies, whose Erase
and Program times increase with accumulated Erase/Pro-
gram cycles.
To meet high density, surface mount requirements, the
SST29SF020/040 and SST29VF020/040 devices are
offered in 32-lead PLCC and 32-lead TSOP packages. The
pin assignments are shown in Figures 2 and 3.
The SST logo and SuperFlash are registered trademarks of Silicon Storage Technology, Inc.
SSF is a trademark of Silicon Storage Technology, Inc.
These specifications are subject to change without notice.
2 Mbit / 4 Mbit Small-Sector Flash
SST29SF020 / SST29SF040
SST29VF020 / SST29VF040
Data Sheet
Device Operation
Commands are used to initiate the memory operation func-
tions of the device. Commands are written to the device
using standard microprocessor write sequences. A com-
mand is written by asserting WE# low while keeping CE#
low. The address bus is latched on the falling edge of WE#
or CE#, whichever occurs last. The data bus is latched on
the rising edge of WE# or CE#, whichever occurs first.
sixth WE# pulse, while the command (20H) is latched on
the rising edge of the sixth WE# pulse. The internal Erase
operation begins after the sixth WE# pulse. The End-of-
Erase operation can be determined using either Data#
Polling or Toggle Bit methods. For timing waveforms, see
Figure 9. Any commands issued during the Sector-Erase
operation are ignored.
Chip-Erase Operation
The SST29SF020/040 and SST29VF020/040 devices
provide a Chip-Erase operation, which allows the user to
erase the entire memory array to the “1s” state. This is use-
ful when the entire device must be quickly erased.
The Chip-Erase operation is initiated by executing a six-
byte Software Data Protection command sequence with
Chip-Erase command (10H) with address 555H in the last
byte sequence. The internal Erase operation begins with
the rising edge of the sixth WE# or CE#, whichever occurs
first. During the internal Erase operation, the only valid read
is Toggle Bit or Data# Polling. See Table 4 for the command
sequence, Figure 10 for the timing diagram, and Figure 19
for the flowchart. Any commands written during the Chip-
Erase operation will be ignored.
Read
The Read operation of the SST29SF020/040 and
SST29VF020/040 devices are controlled by CE# and
OE#, both have to be low for the system to obtain data from
the outputs. CE# is used for device selection. When CE# is
high, the chip is deselected and only standby power is con-
sumed. OE# is the output control and is used to gate data
from the output pins. The data bus is in high impedance
state when either CE# or OE# is high. Refer to the Read
cycle timing diagram in Figure 4 for further details.
Byte-Program Operation
The SST29SF020/040 and SST29VF020/040 devices
are programmed on a byte-by-byte basis. Before program-
ming, the sector where the byte exists must be fully erased.
The Program operation is accomplished in three steps. The
first step is the three-byte load sequence for Software Data
Protection. The second step is to load byte address and
byte data. During the Byte-Program operation, the
addresses are latched on the falling edge of either CE# or
WE#, whichever occurs last. The data is latched on the ris-
ing edge of either CE# or WE#, whichever occurs first. The
third step is the internal Program operation which is initi-
ated after the rising edge of the fourth WE# or CE#, which-
ever occurs first. The Program operation, once initiated, will
be completed, within 20 µs. See Figures 5 and 6 for WE#
and CE# controlled Program operation timing diagrams
and Figure 16 for flowcharts. During the Program opera-
tion, the only valid reads are Data# Polling and Toggle Bit.
During the internal Program operation, the host is free to
perform additional tasks. Any commands written during the
internal Program operation will be ignored.
Write Operation Status Detection
The SST29SF020/040 and SST29VF020/040 devices
provide two software means to detect the completion of a
Write (Program or Erase) cycle, in order to optimize the
system Write cycle time. The software detection includes
two status bits: Data# Polling (DQ
7
) and Toggle Bit (DQ
6
).
The End-of-Write detection mode is enabled after the ris-
ing edge of WE# which initiates the internal Program or
Erase operation.
The actual completion of the nonvolatile write is asyn-
chronous with the system; therefore, either a Data# Poll-
ing or Toggle Bit read may be simultaneous with the
completion of the Write cycle. If this occurs, the system
may possibly get an erroneous result, i.e., valid data may
appear to conflict with either DQ
7
or DQ
6
. In order to pre-
vent spurious rejection, if an erroneous result occurs, the
software routine should include a loop to read the
accessed location an additional two (2) times. If both
reads are valid, then the device has completed the Write
cycle, otherwise the rejection is valid.
Sector-Erase Operation
The Sector-Erase operation allows the system to erase the
device on a sector-by-sector basis. The SST29SF020/
040 and SST29VF020/040 offer Sector-Erase mode. The
sector architecture is based on uniform sector size of 128
Bytes. The Sector-Erase operation is initiated by executing
a six-byte command sequence with Sector-Erase com-
mand (20H) and sector address (SA) in the last bus cycle.
The sector address is latched on the falling edge of the
©2009 Silicon Storage Technology, Inc.
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2 Mbit / 4 Mbit Small-Sector Flash
SST29SF020 / SST29SF040
SST29VF020 / SST29VF040
Data Sheet
Data# Polling (DQ
7
)
When the SST29SF020/040 and SST29VF020/040
devices are in the internal Program operation, any
attempt to read DQ
7
will produce the complement of the
true data. Once the Program operation is completed,
DQ
7
will produce true data. Note that even though DQ
7
may have valid data immediately following the completion
of an internal Write operation, the remaining data outputs
may still be invalid: valid data on the entire data bus will
appear in subsequent successive Read cycles after an
interval of 1 µs. During internal Erase operation, any
attempt to read DQ
7
will produce a ‘0’. Once the internal
Erase operation is completed, DQ
7
will produce a ‘1’. The
Data# Polling is valid after the rising edge of fourth WE#
(or CE#) pulse for Program operation. For Sector- or
Chip-Erase, the Data# Polling is valid after the rising
edge of sixth WE# (or CE#) pulse. See Figure 7 for
Data# Polling timing diagram and Figure 17 for a flow-
chart.
Hardware Data Protection
Noise/Glitch Protection: A WE# or CE# pulse of less than 5
ns will not initiate a Write cycle.
V
DD
Power Up/Down Detection: The Write operation is
inhibited when V
DD
is less than 2.5V for SST29SF020/
040. The Write operation is inhibited when V
DD
is less than
1.5V. for SST29VF020/040.
Write Inhibit Mode: Forcing OE# low, CE# high, or WE#
high will inhibit the Write operation. This prevents inadvert-
ent writes during power-up or power-down.
Software Data Protection (SDP)
The SST29SF020/040 and SST29VF020/040 provide
the JEDEC approved Software Data Protection scheme for
all data alteration operations, i.e., Program and Erase. Any
Program operation requires the inclusion of a series of
three- byte sequence. The three-byte load sequence is
used to initiate the Program operation, providing optimal
protection from inadvertent Write operations, e.g., during
the system power-up or power-down. Any Erase operation
requires the inclusion of a six-byte load sequence. These
devices are shipped with the Software Data Protection per-
manently enabled. The specific software command codes
are shown in Table 4. During SDP command sequence,
invalid commands will abort the device to read mode, within
T
RC.
Toggle Bit (DQ
6
)
During the internal Program or Erase operation, any con-
secutive attempts to read DQ
6
will produce alternating ‘0’s
and ‘1’s, i.e., toggling between 0 and 1. When the internal
Program or Erase operation is completed, the toggling will
stop. The device is then ready for the next operation. The
Toggle Bit is valid after the rising edge of fourth WE# (or
CE#) pulse for Program operation. For Sector or Chip-
Erase, the Toggle Bit is valid after the rising edge of sixth
WE# (or CE#) pulse. See Figure 8 for Toggle Bit timing dia-
gram and Figure 17 for a flowchart.
Data Protection
The SST29SF020/040 and SST29VF020/040 devices
provide both hardware and software features to protect
nonvolatile data from inadvertent writes.
©2009 Silicon Storage Technology, Inc.
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2 Mbit / 4 Mbit Small-Sector Flash
SST29SF020 / SST29SF040
SST29VF020 / SST29VF040
Data Sheet
Product Identification
The Product Identification mode identifies the devices as
SST29SF020,
SST29SF040
and
SST29VF020,
SST29VF040 and manufacturer as SST. This mode may
be accessed by software operations. Users may use the
Software Product Identification operation to identify the part
(i.e., using the device ID) when using multiple manufactur-
ers in the same socket. For details, see Table 4 for software
operation, Figure 11 for the Software ID Entry and Read
timing diagram, and Figure 18 for the Software ID Entry
command sequence flowchart.
TABLE 1: Product Identification
Address
Manufacturer’s ID
Device ID
SST29SF020
SST29VF020
SST29SF040
SST29VF040
0001H
0001H
0001H
0001H
24H
25H
13H
14H
T1.3 1160
Product Identification Mode Exit/Reset
In order to return to the standard Read mode, the Software
Product Identification mode must be exited. Exit is accom-
plished by issuing the Software ID Exit command
sequence, which returns the device to the Read operation.
Please note that the Software ID Exit command is ignored
during an internal Program or Erase operation. See Table 4
for software command codes, Figure 12 for timing wave-
form, and Figure 18 for a flowchart.
Data
BFH
0000H
X-Decoder
SuperFlash
Memory
Memory
Address
Address Buffers & Latches
Y-Decoder
CE#
OE#
WE#
DQ
7
- DQ
0
1160 B1.0
Control Logic
I/O Buffers and Data Latches
FIGURE 1: Functional Block Diagram
©2009 Silicon Storage Technology, Inc.
S71160-15-000
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2 Mbit / 4 Mbit Small-Sector Flash
SST29SF020 / SST29SF040
SST29VF020 / SST29VF040
Data Sheet
SST29SF/VF020 SST29SF/VF040
WE#
WE#
VDD
A12
A15
A16
A18
VDD
A12
A15
A16
SST29SF/VF040 SST29SF/VF020
A17
SST29SF/VF020 SST29SF/VF040
A7
A6
A5
A4
A3
A2
A1
A0
DQ0
A7
A6
A5
A4
A3
A2
A1
A0
DQ0
5
6
7
8
9
10
11
12
13
SST29SF/VF040 SST29SF/VF020
4
3
2
1
NC
32 31 30
29
28
27
26
25
24
23
22
A17
A14
A13
A8
A9
A11
OE#
A10
CE#
DQ7
A14
A13
A8
A9
A11
OE#
A10
CE#
DQ7
32-lead PLCC
Top View
21
14 15 16 17 18 19 20
DQ1
DQ2
DQ3
DQ4
DQ5
DQ6
VSS
1160 32-plcc NH P1.2
DQ1
DQ2
VSS
DQ3
DQ4
DQ5
FIGURE 2: Pin Assignments for 32-lead PLCC
SST29SF/VF040 SST29SF/VF020
A11
A9
A8
A13
A14
A17
WE#
VDD
A18
A16
A15
A12
A7
A6
A5
A4
A11
A9
A8
A13
A14
A17
WE#
VDD
NC
A16
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
1160 32-tsop WH P2.2
DQ6
SST29SF/VF020 SST29SF/VF040
OE#
A10
CE#
DQ7
DQ6
DQ5
DQ4
DQ3
VSS
DQ2
DQ1
DQ0
A0
A1
A2
A3
OE#
A10
CE#
DQ7
DQ6
DQ5
DQ4
DQ3
VSS
DQ2
DQ1
DQ0
A0
A1
A2
A3
Standard Pinout
Top View
Die Up
FIGURE 3: Pin Assignments for 32-lead TSOP (8mm x 14mm)
©2009 Silicon Storage Technology, Inc.
S71160-15-000
2/09
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Microchip MCU
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