©2011 Silicon Storage Technology, Inc. DS25080A 11/11
13
2 Mbit SPI Serial Flash
SST25LF020A
Not Recommended for New Designs
Microchip Technology Company
Sector-Erase
The Sector-Erase instruction clears all bits in the selected 4 KByte sector to FFH. A Sector-Erase
instruction applied to a protected memory area will be ignored. Prior to any Write operation, the Write-
Enable (WREN) instruction must be executed. CE# must remain active low for the duration of the any
command sequence. The Sector-Erase instruction is initiated by executing an 8-bit command, 20H, fol-
lowed by address bits [A
23
-A
0
]. Address bits [A
MS
-A
12
](A
MS
= Most Significant address) are used to
determine the sector address (SA
X
), remaining address bits can be V
IL
or V
IH.
CE# must be driven high
before the instruction is executed. The user may poll the Busy bit in the software status register or wait
T
SE
for the completion of the internal self-timed Sector-Erase cycle. See Figure 9 for the Sector-Erase
sequence.
Figure 9: Sector-Erase Sequence
Block-Erase
The Block-Erase instruction clears all bits in the selected 32 KByte block to FFH. A Block-Erase
instruction applied to a protected memory area will be ignored. Prior to any Write operation, the Write-
Enable (WREN) instruction must be executed. CE# must remain active low for the duration of any com-
mand sequence. The Block-Erase instruction is initiated by executing an 8-bit command, 52H, followed
by address bits [A
23
-A
0
]. Address bits [A
MS
-A
15
](A
MS
= Most significant address) are used to deter-
mine block address (BA
X
), remaining address bits can be V
IL
or V
IH
. CE# must be driven high before the
instruction is executed. The user may poll the Busy bit in the software status register or wait T
BE
for the com-
pletion of the internal self-timed Block-Erase cycle. See Figure 10 for the Block-Erase sequence.
Figure 10: Block-Erase Sequence
CE#
SO
SI
SCK
ADD.
012345678
ADD. ADD.
20
HIGH IMPEDANCE
15 16
23
24
31
MODE 0
MODE 3
1242 F08.0
MSBMSB
CE#
SO
SI
SCK
ADD.
012345678
ADD. ADD.
52
HIGH IMPEDANCE
15 16
23
24
31
MODE 0
MODE 3
1242 F09.0
MSB MSB