2 Mbit / 4 Mbit SPI Serial Flash
SST25LF020A / SST25LF040A
Data Sheet
Instructions
Instructions are used to Read, Write (Erase and Program),
and configure the SST25LF020A/040A. The instruction
bus cycles are 8 bits each for commands (Op Code), data,
and addresses. Prior to executing any Byte-Program, Auto
Address Increment (AAI) programming, Sector-Erase,
Block-Erase, or Chip-Erase instructions, the Write-Enable
(WREN) instruction must be executed first. The complete
list of the instructions is provided in Table 6. All instructions
are synchronized off a high to low transition of CE#. Inputs
will be accepted on the rising edge of SCK starting with the
most significant bit. CE# must be driven low before an
instruction is entered and must be driven high after the last
bit of the instruction has been shifted in (except for Read,
Read-ID and Read-Status-Register instructions). Any low
to high transition on CE#, before receiving the last bit of an
instruction bus cycle, will terminate the instruction in
progress and return the device to the standby mode.
Instruction commands (Op Code), addresses, and data are
all input from the most significant bit (MSB) first.
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TABLE 6: DEVICE OPERATION INSTRUCTIONS
Bus Cycle4
Max
Freq
MHz
1
2
3
4
5
6
Cycle Type/
Operation2,3
SIN
03H
0BH
20H
52H
60H
02H
AFH
SOUT
Hi-Z
Hi-Z
Hi-Z
Hi-Z
Hi-Z
Hi-Z
Hi-Z
SIN
SOUT
Hi-Z
Hi-Z
Hi-Z
Hi-Z
-
SIN
SOUT
Hi-Z
Hi-Z
Hi-Z
Hi-Z
-
SIN
A7-A0
A7-A0
A7-A0
A7-A0
-
SOUT SIN SOUT SIN SOUT
Read
20
A23-A16
A23-A16
A15-A8
A15-A8
A15-A8
A15-A8
-
Hi-Z
Hi-Z
Hi-Z
Hi-Z
-
X
X
DOUT
High-Speed-Read
Sector-Erase5,6
Block-Erase5,7
Chip-Erase6
Byte-Program6
X
X
DOUT
A
23-A16
-
-
-
A23-A16
-
-
-
-
A23-A16
Hi-Z
Hi-Z
A15-A8
A15-A8
Hi-Z
Hi-Z
A7-A0
A7-A0
Hi-Z
Hi-Z
DIN
DIN
Hi-Z
Hi-Z
Auto Address Increment
A
23-A16
(AAI) Single-Byte Program6,8
Read-Status-Register
(RDSR)
05H
50H
01H
Hi-Z
Hi-Z
Hi-Z
X
-
DOUT
-
-
-
-
Note9
-
-
Note9
-
-
-
Note9
33
Enable-Write-Status-Register
(EWSR)10
-
-
-
-
-
-
Write-Status-Register
(WRSR)10
Data
Hi-Z
-.
Write-Enable (WREN)
Write-Disable (WRDI)
Read-ID
06H
04H
Hi-Z
Hi-Z
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
12
90H or Hi-Z
ABH
00H
Hi-Z
00H
Hi-Z
ID
Hi-Z
X
DOUT
Addr11
T6.0 1242
1. AMS = Most Significant Address
AMS = A17 for SST25LF020A and A18 for SST25LF040A
Address bits above the most significant bit of each density can be VIL or VIH
2. Operation: SIN = Serial In, SOUT = Serial Out
3. X = Dummy Input Cycles (VIL or VIH); - = Non-Applicable Cycles (Cycles are not necessary)
4. One bus cycle is eight clock periods.
5. Sector addresses: use AMS-A12, remaining addresses can be VIL or VIH
6. Prior to any Byte-Program, AAI-Program, Sector-Erase, Block-Erase, or Chip-Erase operation, the Write-Enable (WREN) instruction
must be executed.
7. Block addresses for: use AMS-A15, remaining addresses can be VIL or VIH
8. To continue programming to the next sequential address location, enter the 8-bit command, AFH,
followed by the data to be programmed.
9. The Read-Status-Register is continuous with ongoing clock cycles until terminated by a low to high transition on CE#.
10. The Enable-Write-Status-Register (EWSR) instruction and the Write-Status-Register (WRSR) instruction must work in conjunction of
each other. The WRSR instruction must be executed immediately (very next bus cycle) after the EWSR instruction to make both
instructions effective.
11. Manufacturer’s ID is read with A0=0, and Device ID is read with A0=1. All other address bits are 00H. The Manufacturer and Device
ID output stream is continuous until terminated by a low to high transition on CE#
12. Device ID = 43H for SST25LF020A and 44H for SST25LF040A
©2006 Silicon Storage Technology, Inc.
S71242-05-000
1/06
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SST [ SILICON STORAGE TECHNOLOGY, INC ]
