2
Preliminary Specifications
32 Mbit Multi-Purpose Flash Plus
SST39VF3201C / SST39VF3202C
©2010 Silicon Storage Technology, Inc. S71410-01-000 08/10
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 SST39VF3201C/3202C 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 IDD active read current from
typically 9 mA to typically 4 µA. The Auto Low Power mode
reduces the typical IDD active read current to the range of 2
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.
Read
The Read operation of the SST39VF3201C/3202C 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 selection. When CE# is high, the chip is dese-
lected 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 (Figure 5).
Word-Program Operation
The SST39VF3201C/3202C are programmed on a word-
by-word basis. Before programming, the sector where the
word 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 word address and word data. During the
Word-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
Program operation which is initiated after the rising edge of
the fourth WE# or CE#, whichever occurs first. The Pro-
gram operation, once initiated, will be completed within 10
µs. See Figure 6 and Figure 7 for WE# and CE# controlled
Program operation timing diagrams and Figure 21 for flow-
charts. During the Program operation, the only valid reads
are Data# Polling and Toggle Bit. During the internal Pro-
gram operation, the host is free to perform additional tasks.
Any commands issued during the internal Program opera-
tion are ignored. During the command sequence, WP#
should be statically held high or low.
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 SST39VF3201C/3202C offer both Sec-
tor-Erase and Block-Erase mode. The sector architecture
is based on uniform sector size of 2 KWord. The Block-
Erase mode is based on block sizes of 4 and 32 KWord.
The Sector-Erase operation is initiated by executing a six-
byte command sequence with Sector-Erase command
(50H) 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 (30H)
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 (50H or 30H) 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 Figure 11 and Figure 12
for timing waveforms and Figure 25 for the flowchart. Any
commands issued during the Sector- or Block-Erase oper-
ation are ignored. When WP# is low, any attempt to Sector-
(Block-) Erase the protected block will be ignored. During
the command sequence, WP# should be statically held
high or low.
Erase-Suspend/Erase-Resume Commands
The Erase-Suspend operation temporarily suspends a
Sector- or Block-Erase operation thus allowing data to be
read from any memory location, or program data into any
sector/block that is not suspended for an Erase operation.
The operation is executed by issuing one byte command
sequence with Erase-Suspend command (B0H). The
device automatically enters read mode typically within 10
µs after the Erase-Suspend command had been issued.
Valid data can be read from any sector or block that is not
suspended from an Erase operation. Reading at address
location within erase-suspended sectors/blocks will output
DQ2toggling and DQ6at ‘1’. While in Erase-Suspend
mode, a Word-Program operation is allowed except for the
sector or block selected for Erase-Suspend.
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.