2 Mbit / 4 Mbit SPI Serial Flash
SST25LF020A / SST25LF040A
Data Sheet
Byte-Program
The Byte-Program instruction programs the bits in the
selected byte to the desired data. The selected byte must
be in the erased state (FFH) when initiating a Program
operation. A Byte-Program instruction applied to a pro-
tected 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 Byte-Program instruction. The Byte-
Program instruction is initiated by executing an 8-bit com-
mand, 02H, followed by address bits [A
23
-A
0
]. Following the
address, the data is input in order from MSB (bit 7) to LSB
(bit 0). 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
BP
for the completion of the internal
self-timed Byte-Program operation. See Figure 6 for the
Byte-Program sequence.
CE#
MODE 3
0 1 2 3 4 5 6 7 8
15 16
23 24
31 32
39
SCK
MODE 0
SI
MSB
02
ADD.
MSB
ADD.
ADD.
D
IN
MSB
LSB
SO
HIGH IMPEDANCE
1242 F06.0
FIGURE 6: B
YTE
-P
ROGRAM
S
EQUENCE
©2006 Silicon Storage Technology, Inc.
S71242-05-000
1/06
11
SST [ SILICON STORAGE TECHNOLOGY, INC ]
