8 Mbit Multi-Purpose Flash
SST39LF080 / SST39VF080
EOL 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.
The SST39LF/VF080 also have the
Auto Low Power
mode which puts the device in a near standby mode after
data has been accessed with a valid Read operation. This
reduces the I
DD
active read current from typically 15 mA to
typically 4 µA. The Auto Low Power mode reduces the typi-
cal I
DD
active read current to the range of 1 mA/MHz of
Read cycle time. The device exits the Auto Low Power
mode with any address transition or control signal transition
used to initiate another Read cycle, with no access time
penalty. Note that the device does not enter Auto Low
Power mode after power-up with CE# held steadily low until
the first address transition or CE# is driven high.
operation, the host is free to perform additional tasks. Any
commands issued during the internal Program operation
are ignored.
Sector/Block-Erase Operation
The Sector- (or Block-) Erase operation allows the system
to erase the device on a sector-by-sector (or block-by-
block) basis. The SST39LF/VF080 offer both Sector-Erase
and Block-Erase mode. The sector architecture is based
on uniform sector size of 4 KByte. The Block-Erase mode
is based on uniform block size of 64 KByte. The Sector-
Erase operation is initiated by executing a six-byte com-
mand sequence with Sector-Erase command (30H) and
sector address (SA) in the last bus cycle. 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 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 9 and 10 for tim-
ing waveforms. Any commands issued during the Sector-
or Block-Erase operation are ignored.
Read
The Read operation of the SST39LF/VF080 is controlled
by CE# and OE#, both have to be low for the system to
obtain data from the outputs. CE# is used for device selec-
tion. When CE# is high, the chip is deselected and only
standby power is consumed. 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 for further details
Chip-Erase Operation
The SST39LF/VF080 provide a Chip-Erase operation,
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 8 for timing diagram,
and Figure 19 for the flowchart. Any commands issued dur-
ing the Chip-Erase operation are ignored.
Byte-Program Operation
The SST39LF/VF080 are programmed on a byte-by-byte
basis. Before programming, 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 rising edge of either CE# or WE#,
whichever occurs first. The third step is the internal Pro-
gram operation which is initiated after the rising edge of the
fourth WE# or CE#, whichever occurs first. The Program
operation, once initiated, will be completed within 20 µs.
See Figures 4 and 5 for WE# and CE# controlled Program
operation timing diagrams and Figure 16 for flowcharts.
During the Program operation, the only valid reads are
Data# Polling and Toggle Bit. During the internal Program
Write Operation Status Detection
The SST39LF/VF080 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.
©2007 Silicon Storage Technology, Inc.
S71146-07-EOL
6/07
2
SST [ SILICON STORAGE TECHNOLOGY, INC ]
