512 Kbit / 1 Mbit / 2 Mbit / 4 Mbit Multi-Purpose Flash
SST39LF512 / SST39LF010 / SST39LF020 / SST39LF040
SST39VF512 / SST39VF010 / SST39VF020 / SST39VF040
Data Sheet
Data# Polling (DQ7)
Software Data Protection (SDP)
When the SST39LF512/010/020/040 and SST39VF512/
010/020/040 are in the internal Program operation, any
attempt to read DQ7 will produce the complement of the
true data. Once the Program operation is completed, DQ7
will produce true data. The device is then ready for the next
operation. During internal Erase operation, any attempt to
read DQ7 will produce a ‘0’. Once the internal Erase opera-
tion is completed, DQ7 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 16 for a flowchart.
The SST39LF512/010/020/040 and SST39VF512/010/
020/040 provide the JEDEC approved Software Data Pro-
tection scheme for all data alteration operation, i.e., Pro-
gram 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 opera-
tion, 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. These devices are shipped with the
Software Data Protection permanently enabled. See Table
4 for the specific software command codes. During SDP
command sequence, invalid commands will abort the
device to read mode, within TRC
.
Toggle Bit (DQ6)
Product Identification
During the internal Program or Erase operation, any con-
secutive attempts to read DQ6 will produce alternating 0s
and 1s, 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 16 for a flowchart.
The Product Identification mode identifies the devices as
the SST39LF/VF512, SST39LF/VF010, SST39LF/VF020
and SST39LF/VF040 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 multi-
ple manufacturers 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 17 for the
Software ID entry command sequence flowchart.
Data Protection
TABLE 1: PRODUCT IDENTIFICATION
The SST39LF512/010/020/040 and SST39VF512/010/
020/040 provide both hardware and software features to
protect nonvolatile data from inadvertent writes.
Address
Data
Manufacturer’s ID
Device ID
0000H
BFH
Hardware Data Protection
SST39LF/VF512
SST39LF/VF010
SST39LF/VF020
SST39LF/VF040
0001H
0001H
0001H
0001H
D4H
D5H
D6H
D7H
Noise/Glitch Protection: A WE# or CE# pulse of less than 5
ns will not initiate a Write cycle.
VDD Power Up/Down Detection: The Write operation is
inhibited when VDD is less than 1.5V.
T1.1 395
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.
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 17 for a flowchart.
©2001 Silicon Storage Technology, Inc.
S71150-03-000 6/01 395
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SST [ SILICON STORAGE TECHNOLOGY, INC ]
