16 Mbit / 32 Mbit / 64 Mbit Multi-Purpose Flash Plus
SST39VF1601 / SST39VF3201 / SST39VF6401
SST39VF1602 / SST39VF3202 / SST39VF6402
Preliminary Specifications
To resume Sector-Erase or Block-Erase operation which has
been suspended the system must issue Erase Resume
command. The operation is executed by issuing one byte
command sequence with Erase Resume command (30H)
at any address in the last Byte sequence.
ing 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 oper-
ation, 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-,
Block- or Chip-Erase, the Data# Polling is valid after the
rising edge of sixth WE# (or CE#) pulse. See Figure 6 for
Data# Polling timing diagram and Figure 20 for a flowchart.
Chip-Erase Operation
The SST39VF160x/320x/640x provide a Chip-Erase oper-
ation, 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 6 for the command sequence, Figure 9 for tim-
ing diagram, and Figure 23 for the flowchart. Any com-
mands issued during the Chip-Erase operation are
ignored. When WP# is low, any attempt to Chip-Erase will
be ignored. During the command sequence, WP# should
be statically held high or low.
Toggle Bits (DQ6 and DQ2)
During the internal Program or Erase operation, any con-
secutive attempts to read DQ
6
will produce alternating “1”s
and “0”s, i.e., toggling between 1 and 0. When the internal
Program or Erase operation is completed, the DQ
6
bit will
stop toggling. The device is then ready for the next opera-
tion. For Sector-, Block-, or Chip-Erase, the toggle bit (DQ
6
)
is valid after the rising edge of sixth WE# (or CE#) pulse.
DQ
6
will be set to “1” if a Read operation is attempted on an
Erase-Suspended Sector/Block. If Program operation is ini-
tiated in a sector/block not selected in Erase-Suspend
mode, DQ
6
will toggle.
An additional Toggle Bit is available on DQ
2
, which can be
used in conjunction with DQ
6
to check whether a particular
sector is being actively erased or erase-suspended. Table 1
shows detailed status bits information. The Toggle Bit
(DQ
2
) is valid after the rising edge of the last WE# (or CE#)
pulse of Write operation. See Figure 7 for Toggle Bit timing
diagram and Figure 20 for a flowchart.
TABLE 1: W
RITE
O
PERATION
S
TATUS
Status
Normal
Standard
Operation Program
Standard
Erase
Erase-
Suspend
Mode
Read from
Erase-Suspended
Sector/Block
Read from
Non- Erase-Suspended
Sector/Block
Program
Write Operation Status Detection
The SST39VF160x/320x/640x 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 rising 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.
DQ
7
DQ
7
#
0
1
DQ
6
Toggle
Toggle
1
DQ
2
No Toggle
Toggle
Toggle
Data
Data
Data
DQ
7
#
Toggle
N/A
T1.0 1223
Data# Polling (DQ
7
)
When the SST39VF160x/320x/640x are in the internal
Program operation, any attempt to read DQ
7
will produce
the complement of the true data. Once the Program oper-
ation is completed, DQ
7
will produce true data. Note that
even though DQ
7
may have valid data immediately follow-
©2003 Silicon Storage Technology, Inc.
Note:
DQ
7
and DQ
2
require a valid address when reading
status information.
S71223-03-000
11/03
3
SST [ SILICON STORAGE TECHNOLOGY, INC ]
