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The SST logo and SuperFlash are registered trademarks of Silicon Storage Technology, Inc.

MPF and ComboMemory are trademarks of Silicon Storage Technology, Inc.

These specifications are subject to change without notice.

Data Sheet

FEATURES:

MPF + SRAM ComboMemory

SST32HF802: 512K x16 Flash + 128K x16 SRAM
SST32HF162: 1M x16 Flash + 128K x16 SRAM
SST32HF164: 1M x16 Flash + 256K x16 SRAM

Single 2.7-3.3V Read and Write Operations

Concurrent Operation

Read from or write to SRAM while

Erase/Program Flash

Superior Reliability

Endurance: 100,000 Cycles (typical)
Greater than 100 years Data Retention

Low Power Consumption:

Active Current: 15 mA (typical) for

Flash or SRAM Read

Standby Current: 20 µA (typical)

Flexible Erase Capability

Uniform 2 KWord sectors
Uniform 32 KWord size blocks

Fast Read Access Times:

Flash: 70 ns and 90 ns
SRAM: 70 ns and 90 ns

Latched Address and Data for Flash

Flash Fast Erase and Word-Program:

Sector-Erase Time: 18 ms (typical)
Block-Erase Time: 18 ms (typical)
Chip-Erase Time: 70 ms (typical)
Word-Program Time: 14 µs (typical)
Chip Rewrite Time:

SST32HF802: 8 seconds (typical)
SST32HF162/164: 15 seconds (typical)

Flash Automatic Erase and Program Timing

Internal V

Generation

Flash End-of-Write Detection

Toggle Bit
Data# Polling

CMOS I/O Compatibility

JEDEC Standard Command Set

Package Available

48-lead TSOP (12mm x 20mm)
48-ball TBGA (10mm x 12mm)

PRODUCT DESCRIPTION

The SST32HF802/162/164 ComboMemory devices inte-
grate a 512K x16 or 1M x16 CMOS flash memory bank
with a 128K x16 or 256K x16 CMOS SRAM memory bank
in a Multi-Chip Package (MCP), manufactured with SST's
proprietary, high performance SuperFlash technology.

Featuring high performance Word-Program, the flash
memory bank provides a maximum Word-Program time of
14 µsec. The entire flash memory bank can be erased and
programmed word-by-word in typically 8 seconds for the
SST32HF802 and 15 seconds for the SST32HF162/164,
when using interface features such as Toggle Bit or Data#
Polling to indicate the completion of Program operation. To
protect against inadvertent flash write, the SST32HF802/
162/164 devices contain on-chip hardware and software
data protection schemes.The SST32HF802/162/164
devices offer a guaranteed endurance of 10,000 cycles.
Data retention is rated at greater than 100 years.

The SST32HF802/162/164 devices consist of two inde-
pendent memory banks with respective bank enable sig-
nals. The Flash and SRAM memory banks are
superimposed in the same memory address space. Both
memory banks share common address lines, data lines,
WE# and OE#. The memory bank selection is done by
memory bank enable signals. The SRAM bank enable sig-
nal, BES# selects the SRAM bank. The flash memory

bank enable signal, BEF# selects the flash memory bank.
The WE# signal has to be used with Software Data Protec-
tion (SDP) command sequence when controlling the Erase
and Program operations in the flash memory bank. The
SDP command sequence protects the data stored in the
flash memory bank from accidental alteration.

The SST32HF802/162/164 provide the added functionality
of being able to simultaneously read from or write to the
SRAM bank while erasing or programming in the flash
memory bank. The SRAM memory bank can be read or
written while the flash memory bank performs Sector-
Erase, Bank-Erase, or Word-Program concurrently. All
flash memory Erase and Program operations will automati-
cally latch the input address and data signals and complete
the operation in background without further input stimulus
requirement. Once the internally controlled erase or pro-
gram cycle in the flash bank has commenced, the SRAM
bank can be accessed for read or write.

The SST32HF802/162/164 devices are suited for applica-
tions that use both flash memory and SRAM memory to
store code or data. For systems requiring low power and
small form factor, the SST32HF802/162/164 devices signif-
icantly improve performance and reliability, while lowering
power consumption, when compared with multiple chip
solutions. The SST32HF802/162/164 inherently use less
energy during erase and program than alternative flash

Multi-Purpose Flash (MPF) + SRAM ComboMemory

SST32HF802 / SST32HF162 / SST32HF164

SST32HF802 / 162 / 164MPF (x16) + 1Mb SRAM (x16) ComboMemories

Data Sheet

Multi-Purpose Flash (MPF) + SRAM ComboMemory

SST32HF802 / SST32HF162 / SST32HF164

S71171-05-000

8/01

520

technologies. The total energy consumed is a function of
the applied voltage, current, and time of application. Since
for any given voltage range, the SuperFlash technology
uses less current to program and has a shorter erase time,
the total energy consumed during any Erase or Program
operation is less than alternative flash technologies.

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.

Device Operation

The ComboMemory uses BES# and BEF# to control oper-
ation of either the SRAM or the flash memory bank. When
BES# is low, the SRAM Bank is activated for Read and
Write operation. When BEF# is low the flash bank is acti-
vated for Read, Program or Erase operation. BES# and
BEF# cannot be at low level at the same time. If BES# and
BEF# are both asserted to low level bus contention will
result and the device may suffer permanent damage. All
address, data, and control lines are shared by SRAM Bank
and flash bank which minimizes power consumption and
loading. The device goes into standby when both bank
enables are high.

SRAM Operation

With BES# low and BEF# high, the SST32HF802/162
operate as 128K x16 CMOS SRAM, and the SST32HF164
operates as 256K x16 CMOS SRAM, with fully static oper-
ation requiring no external clocks or timing strobes. The
SST32HF802/162 SRAM is mapped into the first 128
KWord address space of the device, and the SST32HF164
SRAM is mapped into the first 256 KWord address space.
When BES# and BEF# are high, both memory banks are
deselected and the device enters standby mode. Read and
Write cycle times are equal. The control signals UBS# and
LBS# provide access to the upper data byte and lower data
byte. See Table 3 for SRAM read and write data byte con-
trol modes of operation.

SRAM Read

The SRAM Read operation of the SST32HF802/162/164 is
controlled by OE# and BES#, both have to be low with
WE# high for the system to obtain data from the outputs.
BES# is used for SRAM bank selection. OE# is the output
control and is used to gate data from the output pins. The
data bus is in high impedance state when OE# is high. See
Figure 3 for the Read cycle timing diagram.

SRAM Write

The SRAM Write operation of the SST32HF802/162/164
is controlled by WE# and BES# being low for the system
to write to the SRAM. During the Word-Write operation,
the addresses and data are referenced to the rising edge
of WE# or BES#, which ever occurs first. The write time is
measured from the last falling edge to the rising edge of
WE# or BES#. Refer to the Write cycle timing diagrams,
Figures 4 and 5, for further details.

Flash Operation

With BEF# active, the SST32HF162/164 operate as 1M
x16 flash memory and the SST32HF802 operates as 512K
x16 flash memory. The flash memory bank is read using
the common address lines, data lines, WE# and OE#.
Erase and Program operations are initiated with the
JEDEC standard SDP command sequences. Address and
data are latched during the SDP commands and during the
internally timed Erase and Program operations.

Flash Read

The Read operation of the SST32HF802/162/164 devices
is controlled by BEF# and OE#. Both have to be low, with
WE# high, for the system to obtain data from the outputs.
BEF# is used for flash memory bank selection. When
BEF# and BES# are high, both banks are deselected and
only standby power is consumed. OE# is the output con-
trol and is used to gate data from the output pins. The data
bus is in high impedance state when OE# is high. Refer to
Figure 6 for further details.

Flash Erase/Program Operation

SDP commands are used to initiate the flash memory bank
Program and Erase operations of the SST32HF802/162/
164. SDP commands are loaded to the flash memory bank
using standard microprocessor write sequences. A com-
mand is loaded by asserting WE# low while keeping BEF#
low and OE# high. The address is latched on the falling
edge of WE# or BEF#, whichever occurs last. The data is
latched on the rising edge of WE# or BEF#, whichever
occurs first.

Flash Word-Program Operation

The flash memory bank of the SST32HF802/162/164
devices is programmed on a word-by-word basis. Before
the Program operations, the memory must be erased first.
The Program operation consists of three steps. The first
step is the three-byte load sequence for Software Data Pro-
tection. The second step is to load word address and word
data. During the Word-Program operation, the addresses

Data Sheet

Multi-Purpose Flash (MPF) + SRAM ComboMemory
SST32HF802 / SST32HF162 / SST32HF164

S71171-05-000

8/01

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are latched on the falling edge of either BEF# or WE#,
whichever occurs last. The data is latched on the rising
edge of either BEF# 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 BEF#,
whichever occurs first. The Program operation, once initi-
ated, will be completed, within 20 µs. See Figures 7 and 8
for WE# and BEF# controlled Program operation timing
diagrams and Figure 18 for flowcharts. During the Program
operation, the only valid flash Read operations are Data#
Polling and Toggle Bit. During the internal Program opera-
tion, the host is free to perform additional tasks. Any SDP
commands loaded during the internal Program operation
will be ignored.

Flash Sector/Block-Erase Operation

The Flash Sector/Block-Erase operation allows the system
to erase the device on a sector-by-sector (or block-by-
block) basis. The SST32HF802/162/164 offer both Sector-
Erase and Block-Erase mode. The sector architecture is
based on uniform sector size of 2 KWord. The Block-Erase
mode is based on uniform block size of 32 KWord. The
Sector-Erase operation is initiated by executing a six-byte
command sequence with Sector-Erase command (30H)
and sector address (SA) in the last bus cycle. The address
lines A

-A

, for SST32HF162/164, and A

-A

, for

SST32HF802, are used to determine the sector address.
The Block-Erase operation is initiated by executing a six-
byte command sequence with Block-Erase command
(50H) and block address (BA) in the last bus cycle. The
address lines A

-A

, for SST32HF162/164, and A

-A

for SST32HF802, are used to determine the block address.
The sector or block address is latched on the falling edge of
the sixth WE# pulse, while the command (30H or 50H) 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. See Figures 12
and 13 for timing waveforms. Any commands issued during
the Sector- or Block-Erase operation are ignored.

Flash Chip-Erase Operation

The SST32HF802/162/164 provide a Chip-Erase opera-
tion, which allows the user to erase the entire memory
array to the "1" state. This is useful when the entire device
must be quickly erased.

The Chip-Erase operation is initiated by executing a six-
byte command sequence with Chip-Erase command (10H)
at address 5555H in the last byte sequence. The Erase
operation begins with the rising edge of the sixth WE# or
CE#, whichever occurs first. During the Erase operation,

the only valid read is Toggle Bit or Data# Polling. See Table
4 for the command sequence, Figure 10 for timing diagram,
and Figure 21 for the flowchart. Any commands issued dur-
ing the Chip-Erase operation are ignored.

Write Operation Status Detection

The SST32HF802/162/164 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 soft-
ware detection includes two status bits: Data# Polling
(DQ

) and Toggle Bit (DQ

). The End-of-Write detection

mode is enabled after the rising edge of WE#, which ini-
tiates the internal program or erase operation.

The actual completion of the nonvolatile write is asynchro-
nous with the system; therefore, either a Data# Polling 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 con-
flict with either DQ

or DQ

In order to prevent 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 rejec-
tion is valid.

Flash Data# Polling (DQ

)

When the SST32HF802/162/164 flash memory banks are
in the internal Program operation, any attempt to read DQ

will produce the complement of the true data. Once the
Program operation is completed, DQ

will produce true

data. Note that even though DQ

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. During internal Erase operation,
any attempt to read DQ

will produce a `0'. Once the inter-

nal Erase operation is completed, DQ

will produce a `1'.

The Data# Polling is valid after the rising edge of the fourth
WE# (or BEF#) pulse for Program operation. For Sector- or
Block-Erase, the Data# Polling is valid after the rising edge
of the sixth WE# (or BEF#) pulse. See Figure 9 for Data#
Polling timing diagram and Figure 19 for a flowchart.

Flash Toggle Bit (DQ

)

During the internal Program or Erase operation, any con-
secutive attempts to read DQ

will produce alternating 1s

and 0s, i.e., toggling between 1 and 0. When the internal
Program or Erase operation is completed, the toggling will
stop. The flash memory bank is then ready for the next
operation. The Toggle Bit is valid after the rising edge of the
fourth WE# (or BEF#) pulse for Program operation. For

Data Sheet

Multi-Purpose Flash (MPF) + SRAM ComboMemory

SST32HF802 / SST32HF162 / SST32HF164

S71171-05-000

8/01

520

Sector- or Bank-Erase, the Toggle Bit is valid after the rising
edge of the sixth WE# (or BEF#) pulse. See Figure 10 for
Toggle Bit timing diagram and Figure 19 for a flowchart.

Flash Memory Data Protection

The SST32HF802/162/164 flash memory bank provides
both hardware and software features to protect nonvolatile
data from inadvertent writes.

Flash Hardware Data Protection

Noise/Glitch Protection: A WE# or BEF# pulse of less than
5 ns will not initiate a Write cycle.

Power Up/Down Detection: The Write operation is

inhibited when V

is less than 1.5V.

Write Inhibit Mode: Forcing OE# low, BEF# high, or WE#
high will inhibit the Flash Write operation. This prevents
inadvertent writes during power-up or power-down.

Flash Software Data Protection (SDP)

The SST32HF802/162/164 provide the JEDEC approved
software data protection scheme for all flash memory bank
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 six-byte load sequence. The
SST32HF802/162/164 devices are shipped with the soft-
ware data protection permanently enabled. See Table 4 for
the specific software command codes. During SDP com-
mand sequence, invalid SDP commands will abort the
device to the read mode, within Read Cycle Time (T

Concurrent Read and Write Operations

The SST32HF802/162/164 provide the unique benefit of
being able to read from or write to SRAM, while simulta-
neously erasing or programming the Flash. This allows data
alteration code to be executed from SRAM, while altering
the data in Flash. The following table lists all valid states.

The device will ignore all SDP commands when an Erase
or Program operation is in progress. Note that Product
Identification commands use SDP; therefore, these com-
mands will also be ignored while an Erase or Program
operation is in progress.

Product Identification

The product identification mode identifies the devices as
the SST32HFxxx and manufacturer as SST. This mode
may be accessed by software operations only. The
hardware device ID Read operation, which is typically
used by programmers, cannot be used on this device
because of the shared lines between flash and SRAM
in the multi-chip package. Therefore, application of
high voltage to pin A

may damage this device. Users

may use the software product identification operation to
identify the part (i.e., using the device ID) when using multi-
ple manufacturers in the same socket. For details, see
Tables 3 and 4 for software operation, Figure 14 for the
software ID entry and read timing diagram and Figure 20
for the ID entry command sequence flowchart.

Product Identification Mode Exit/Reset

In order to return to the standard read mode, the Software
Product Identification mode must be exited. Exiting is
accomplished by issuing the Exit ID command sequence,
which returns the device to the Read operation. Please
note that the software-reset command is ignored during an
internal Program or Erase operation. See Table 4 for soft-
ware command codes, Figure 15 for timing waveform and
Figure 20 for a flowchart.

Design Considerations

SST recommends a high frequency 0.1 µF ceramic capac-
itor to be placed as close as possible between V

and

, e.g., less than 1 cm away from the V

pin of the

device. Additionally, a low frequency 4.7 µF electrolytic
capacitor from V

to V

should be placed within 1 cm of

the V

pin.

ONCURRENT

EAD

RITE

TATE

ABLE

Flash

SRAM

Program/Erase

Read

Program/Erase

Write

TABLE

1: P

RODUCT

DENTIFICATION

Address

Data

Manufacturer's ID

0000H

00BFH

Device ID

SST32HF802

0001H

2781H

SST32HF162/164

0001H

2782H

T1.1 520

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