A
Microchip Technology Company
©2011 Silicon Storage Technology, Inc. DS25078A 11/11
Not Recommended for New Designs
www.microchip.com
Features
Single 2.7-3.6V Read and Write Operations
Serial Interface Architecture
SPI Compatible: Mode 0 and Mode 3
20 MHz Max Clock Frequency
Superior Reliability
Endurance: 100,000 Cycles (typical)
Greater than 100 years Data Retention
Low Power Consumption:
Active Read Current: 7 mA (typical)
Standby Current: 8 µA (typical)
Flexible Erase Capability
Uniform 4 KByte sectors
Uniform 32 KByte overlay blocks
Fast Erase and Byte-Program:
Chip-Erase Time: 70 ms (typical)
Sector- or Block-Erase Time: 18 ms (typical)
Byte-Program Time: 14 µs (typical)
Auto Address Increment (AAI) Programming
Decrease total chip programming time over Byte-Pro-
gram operations
End-of-Write Detection
Software Status
Hold Pin (HOLD#)
Suspends a serial sequence to the memory
without deselecting the device
Write Protection (WP#)
Enables/Disables the Lock-Down function of the status
register
Software Write Protection
Write protection through Block-Protection bits in status
register
Temperature Range
Commercial: 0°C to +70°C
Industrial: -40°C to +85°C
Extended: -20°C to +85°C
Packages Available
8-lead SOIC 150 mil body width
8-contact WSON (5mm x 6mm)
All non-Pb (lead-free) devices are RoHS compliant
2 Mbit SPI Serial Flash
SST25VF020
SST's serial flash family features a four-wire, SPI-compatible interface that allows
for a low pin-count package occupying less board space and ultimately lowering
total system costs. SST25VF020 SPI serial flash memory is manufactured with
SST proprietary, high performance CMOS SuperFlash Technology. The split-gate
cell design and thick-oxide tunneling injector attain better reliability and manufac-
turability compared with alternate approaches.
Not recommended for new designs.
Please use SST25VF020B
©2011 Silicon Storage Technology, Inc. DS25078A 11/11
2
2 Mbit SPI Serial Flash
SST25VF020
Not Recommended for New Designs
A
Microchip Technology Company
Product Description
The SST serial flash family features a four-wire, SPI-compatible interface that allows for a low pin-
count package occupying less board space and ultimately lowering total system costs. SST25VF020
SPI serial flash memories are manufactured with SST’s proprietary, high performance CMOS Super-
Flash Technology. The split-gate cell design and thick-oxide tunneling injector attain better reliability
and manufacturability compared with alternate approaches.
The SST25VF020 device significantly improves performance, while lowering power consumption. The
total energy consumed is a function of the applied voltage, current, and time of application. Since for
any given voltage range, the SuperFlash technology uses less current to program and has a shorter
erase time, the total energy consumed during any Erase or Program operation is less than alternative
flash memory technologies. The SST25VF020 device operates with a single 2.7-3.6V power supply.
The SST25VF020 device is offered in an 8-lead SOIC 150 mil body width (SA) package, and in an 8-
contact WSON package. See Figure 2 for the pin assignments.
©2011 Silicon Storage Technology, Inc. DS25078A 11/11
3
2 Mbit SPI Serial Flash
SST25VF020
Not Recommended for New Designs
A
Microchip Technology Company
Block Diagram
Figure 1: Functional Block Diagram
1231 B1.0
I/O Buffers
and
Data Latches
SuperFlash
Memory
X - Decoder
Control Logic
Address
Buffers
and
Latches
CE#
Y - Decoder
SCK SI SO WP# HOLD#
Serial Interface
©2011 Silicon Storage Technology, Inc. DS25078A 11/11
4
2 Mbit SPI Serial Flash
SST25VF020
Not Recommended for New Designs
A
Microchip Technology Company
Pin Description
Figure 2: Pin Assignments
Table 1: Pin Description
Symbol Pin Name Functions
SCK Serial Clock To provide the timing of the serial interface.
Commands, addresses, or input data are latched on the rising edge of the clock input,
while output data is shifted out on the falling edge of the clock input.
SI Serial Data
Input
To transfer commands, addresses, or data serially into the device.
Inputs are latched on the rising edge of the serial clock.
SO Serial Data
Output
To transfer data serially out of the device.
Data is shifted out on the falling edge of the serial clock.
CE# Chip Enable The device is enabled by a high to low transition on CE#. CE# must remain low for the
duration of any command sequence.
WP# Write Protect The Write Protect (WP#) pin is used to enable/disable BPL bit in the status register.
HOLD# Hold To temporarily stop serial communication with SPI flash memory without resetting the
device.
VDD Power Supply To provide power supply (2.7-3.6V).
VSS Ground
T1.0 25078
8-lead SOIC 8-contact WSON
1
2
3
4
8
7
6
5
CE#
SO
WP#
VSS
Top View
VDD
HOLD#
SCK
SI
1231 08-wson P2.0
1
2
3
4
8
7
6
5
CE#
SO
WP#
VSS
VDD
HOLD#
SCK
SI
Top View
1231 08-soic P1.0
©2011 Silicon Storage Technology, Inc. DS25078A 11/11
5
2 Mbit SPI Serial Flash
SST25VF020
Not Recommended for New Designs
A
Microchip Technology Company
Memory Organization
The SST25VF020 SuperFlash memory array is organized in 4 KByte sectors with 32 KByte overlay
blocks.
Device Operation
The SST25VF020 is accessed through the SPI (Serial Peripheral Interface) bus compatible protocol.
The SPI bus consist of four control lines; Chip Enable (CE#) is used to select the device, and data is
accessed through the Serial Data Input (SI), Serial Data Output (SO), and Serial Clock (SCK).
The SST25VF020 supports both Mode 0 (0,0) and Mode 3 (1,1) of SPI bus operations. The difference
between the two modes, as shown in Figure 3, is the state of the SCK signal when the bus master is in
Stand-by mode and no data is being transferred. The SCK signal is low for Mode 0 and SCK signal is
high for Mode 3. For both modes, the Serial Data In (SI) is sampled at the rising edge of the SCK clock
signal and the Serial Data Output (SO) is driven after the falling edge of the SCK clock signal.
Figure 3: SPI Protocol
1231 F02.1
MODE 3
SCK
SI
SO
CE#
MODE 3
DON T CARE
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
MODE 0MODE 0
HIGH IMPEDANCE
MSB
MSB
©2011 Silicon Storage Technology, Inc. DS25078A 11/11
6
2 Mbit SPI Serial Flash
SST25VF020
Not Recommended for New Designs
A
Microchip Technology Company
Hold Operation
HOLD# pin is used to pause a serial sequence underway with the SPI flash memory without resetting
the clocking sequence. To activate the HOLD# mode, CE# must be in active low state. The HOLD#
mode begins when the SCK active low state coincides with the falling edge of the HOLD# signal. The
HOLD mode ends when the HOLD# signal’s rising edge coincides with the SCK active low state.
If the falling edge of the HOLD# signal does not coincide with the SCK active low state, then the device
enters Hold mode when the SCK next reaches the active low state. Similarly, if the rising edge of the
HOLD# signal does not coincide with the SCK active low state, then the device exits in Hold mode
when the SCK next reaches the active low state. See Figure 4 for Hold Condition waveform.
Once the device enters Hold mode, SO will be in high-impedance state while SI and SCK can be VIL or
VIH.
If CE# is driven active high during a Hold condition, it returns the device to standby mode. As long as
HOLD# signal is low, the memory remains in the Hold condition. To resume communication with the
device, HOLD# must be driven active high, and CE# must be driven active low. See Figure 18 for Hold
timing.
Figure 4: Hold Condition Waveform
Write Protection
SST25VF020 provides software Write protection. The Write Protect pin (WP#) enables or disables the
lock-down function of the status register. The Block-Protection bits (BP1, BP0, and BPL) in the status
register provide Write protection to the memory array and the status register. See Table 4 for Block-
Protection description.
Write Protect Pin (WP#)
The Write Protect (WP#) pin enables the lock-down function of the BPL bit (bit 7) in the status register.
When WP# is driven low, the execution of the Write-Status-Register (WRSR) instruction is determined
by the value of the BPL bit (see Table 2). When WP# is high, the lock-down function of the BPL bit is
disabled.
Table 2: Conditions to execute Write-Status-Register (WRSR) Instruction
WP# BPL Execute WRSR Instruction
L 1 Not Allowed
L 0 Allowed
H X Allowed
T2.0 25078
Active Hold Active Hold Active
1231 F03.0
SCK
HOLD#
©2011 Silicon Storage Technology, Inc. DS25078A 11/11
7
2 Mbit SPI Serial Flash
SST25VF020
Not Recommended for New Designs
A
Microchip Technology Company
Status Register
The software status register provides status on whether the flash memory array is available for any
Read or Write operation, whether the device is Write enabled, and the state of the memory Write pro-
tection. During an internal Erase or Program operation, the status register may be read only to deter-
mine the completion of an operation in progress. Table 3 describes the function of each bit in the
software status register.
Busy
The Busy bit determines whether there is an internal Erase or Program operation in progress. A “1” for
the Busy bit indicates the device is busy with an operation in progress. A “0” indicates the device is
ready for the next valid operation.
Write Enable Latch (WEL)
The Write-Enable-Latch bit indicates the status of the internal memory Write Enable Latch. If the
Write-Enable-Latch bit is set to “1”, it indicates the device is Write enabled. If the bit is set to “0” (reset),
it indicates the device is not Write enabled and does not accept any memory Write (Program/Erase)
commands. The Write-Enable-Latch bit is automatically reset under the following conditions:
Power-up
Write-Disable (WRDI) instruction completion
Byte-Program instruction completion
Auto Address Increment (AAI) programming reached its highest memory address
Sector-Erase instruction completion
Block-Erase instruction completion
Chip-Erase instruction completion
Table 3: Software Status Register
Bit Name Function
Default at
Power-up Read/Write
0 BUSY 1 = Internal Write operation is in progress
0 = No internal Write operation is in progress
0R
1 WEL 1 = Device is memory Write enabled
0 = Device is not memory Write enabled
0R
2 BP0 Indicate current level of block write protection (See Table 4) 1 R/W
3 BP1 Indicate current level of block write protection (See Table 4) 1 R/W
4:5 RES Reserved for future use 0 N/A
6 AAI Auto Address Increment Programming status
1 = AAI programming mode
0 = Byte-Program mode
0R
7 BPL 1 = BP1, BP0 are read-only bits
0 = BP1, BP0 are read/writable
0 R/W
T3.0 25078
©2011 Silicon Storage Technology, Inc. DS25078A 11/11
8
2 Mbit SPI Serial Flash
SST25VF020
Not Recommended for New Designs
A
Microchip Technology Company
Block Protection (BP1, BP0)
The Block-Protection (BP1, BP0) bits define the size of the memory area, as defined in Table 4, to be
software protected against any memory Write (Program or Erase) operations. The Write-Status-Regis-
ter (WRSR) instruction is used to program the BP1 and BP0 bits as long as WP# is high or the Block-
Protect-Lock (BPL) bit is 0. Chip-Erase can only be executed if Block-Protection bits are both 0. After
power-up, BP1 and BP0 are set to 1.
Block Protection Lock-Down (BPL)
WP# pin driven low (VIL), enables the Block-Protection-Lock-Down (BPL) bit. When BPL is set to 1, it
prevents any further alteration of the BPL, BP1, and BP0 bits. When the WP# pin is driven high (VIH),
the BPL bit has no effect and its value is “Don’t Care”. After power-up, the BPL bit is reset to 0.
Auto Address Increment (AAI)
The Auto Address Increment Programming-Status bit provides status on whether the device is in AAI
programming mode or Byte-Program mode. The default at power up is Byte-Program mode.
Table 4: Software Status Register Block Protection1
1. Default at power-up for BP1 and BP0 is ‘11’.
Protection Level
Status
Register
Bit
Protected Memory Area
BP1 BP0 2 Mbit
0 0 0 None
1 (1/4 Memory Array) 0 1 030000H-03FFFFH
2 (1/2 Memory Array) 1 0 020000H-03FFFFH
3 (Full Memory Array) 1 1 000000H-03FFFFH
T4.0 25078
©2011 Silicon Storage Technology, Inc. DS25078A 11/11
9
2 Mbit SPI Serial Flash
SST25VF020
Not Recommended for New Designs
A
Microchip Technology Company
Instructions
Instructions are used to Read, Write (Erase and Program), and configure the SST25VF020. The
instruction bus cycles are 8 bits each for commands (Op Code), data, and addresses. Prior to execut-
ing 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 5. 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.
Table 5: Device Operation Instructions1
1. AMS = Most Significant Address
AMS =A
17 for SST25VF020
Address bits above the most significant bit of each density can be VIL or VIH
Bus Cycle2
2. One bus cycle is eight clock periods.
123 4 5
Cycle Type/Operation3,4
3. Operation: SIN = Serial In, SOUT = Serial Out
4. X = Dummy Input Cycles (VIL or VIH); - = Non-Applicable Cycles (Cycles are not necessary)
SIN SOUT SIN SOUT SIN SOUT SIN SOUT SIN SOUT
Read 03H Hi-Z A23-
A16
Hi-Z A15-
A8
Hi-Z A7-A0Hi-Z X DOUT
Sector-Erase5,6
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.
20H Hi-Z A23-
A16
Hi-Z A15-
A8
Hi-Z A7-A0Hi-Z - -
Block-Erase5,7
7. Block addresses for: use AMS-A15, remaining addresses can be VIL or VIH
52H Hi-Z A23-
A16
Hi-Z A15-
A8
Hi-Z A7-A0Hi-Z - -
Chip-Erase660H Hi-Z - - - - - - - -
Byte-Program602H Hi-Z A23-
A16
Hi-Z A15-
A8
Hi-Z A7-A0Hi-Z DI
N
Hi-Z
Auto Address Increment (AAI)
Program6,8
8. To continue programming to the next sequential address location, enter the 8-bit command, AFH,
followed by the data to be programmed.
AFH Hi-Z A23-
A16
Hi-Z A15-
A8
Hi-Z A7-A0Hi-Z DI
N
Hi-Z
Read-Status-Register (RDSR) 05H Hi-Z X DOU
T
- Note
9
9. The Read-Status-Register is continuous with ongoing clock cycles until terminated by a low to high transition on CE#.
- Note
9
- Note9
Enable-Write-Status-Register
(EWSR)10
50H Hi-Z - - - - - - - -
Write-Status-Register
(WRSR)10
01H Hi-Z Data Hi-Z - - -. - - -
Write-Enable (WREN) 06H Hi-Z - - - - - - - -
Write-Disable (WRDI) 04H Hi-Z - - - - - - - -
Read-ID 90H or
ABH
Hi-Z 00H Hi-Z 00H Hi-Z ID
Addr11
Hi-Z X DOUT
12
T5.0 25078
©2011 Silicon Storage Technology, Inc. DS25078A 11/11
10
2 Mbit SPI Serial Flash
SST25VF020
Not Recommended for New Designs
A
Microchip Technology Company
Read
The Read instruction outputs the data starting from the specified address location. The data output
stream is continuous through all addresses until terminated by a low to high transition on CE#. The
internal address pointer will automatically increment until the highest memory address is reached.
Once the highest memory address is reached, the address pointer will automatically increment to the
beginning (wrap-around) of the address space, i.e. for 2 Mbit density, once the data from address loca-
tion 3FFFFH had been read, the next output will be from address location 00000H.
The Read instruction is initiated by executing an 8-bit command, 03H, followed by address bits [A23-
A0]. CE# must remain active low for the duration of the Read cycle. See Figure 5 for the Read
sequence.
Figure 5: Read Sequence
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’s
and Device ID output stream is continuous until terminated by a low to high transition on CE#
12. Device ID = 43H for SST25VF020
1231 F04.1
CE#
SO
SI
SCK
ADD.
012345678
ADD. ADD.
03
HIGH IMPEDANCE
15 16 23 24 31 32 39 40 7047 48 55 56 63 64
N+2 N+3 N+4N N+1
DOUT
MSB MSB
MSB
MODE 0
MODE 3
DOUT DOUT DOUT DOUT
©2011 Silicon Storage Technology, Inc. DS25078A 11/11
11
2 Mbit SPI Serial Flash
SST25VF020
Not Recommended for New Designs
A
Microchip Technology Company
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 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 Byte-Program instruction. The Byte-Program instruction is initiated by
executing an 8-bit command, 02H, followed by address bits [A23-A0]. 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 exe-
cuted. The user may poll the Busy bit in the software status register or wait TBP for the completion of
the internal self-timed Byte-Program operation. See Figure 6 for the Byte-Program sequence.
Figure 6: Byte-Program Sequence
1231 F05.1
CE#
SO
SI
SCK
ADD.
012345678
ADD. ADD. DIN
02
HIGH IMPEDANCE
15 16 23 24 31 32 39
MODE 0
MODE 3
MSBMSB
MSB LSB
©2011 Silicon Storage Technology, Inc. DS25078A 11/11
12
2 Mbit SPI Serial Flash
SST25VF020
Not Recommended for New Designs
A
Microchip Technology Company
Auto Address Increment (AAI) Program
The AAI program instruction allows multiple bytes of data to be programmed without re-issuing the
next sequential address location. This feature decreases total programming time when the entire mem-
ory array is to be programmed. An AAI program instruction pointing to a protected memory area will be
ignored. The selected address range must be in the erased state (FFH) when initiating an AAI program
instruction.
Prior to any write operation, the Write-Enable (WREN) instruction must be executed. The AAI program
instruction is initiated by executing an 8-bit command, AFH, followed by address bits [A23-A0]. Follow-
ing the addresses, the data is input sequentially from MSB (bit 7) to LSB (bit 0). CE# must be driven
high before the AAI program instruction is executed. The user must poll the BUSY bit in the software
status register or wait TBP for the completion of each internal self-timed Byte-Program cycle. Once the
device completes programming byte, the next sequential address may be program, enter the 8-bit
command, AFH, followed by the data to be programmed. When the last desired byte had been pro-
grammed, execute the Write-Disable (WRDI) instruction, 04H, to terminate AAI. After execution of the
WRDI command, the user must poll the Status register to ensure the device completes programming.
See Figure 7 for AAI programming sequence.
There is no wrap mode during AAI programming; once the highest unprotected memory address is
reached, the device will exit AAI operation and reset the Write-Enable-Latch bit (WEL = 0).
Figure 7: Auto Address Increment (AAI) Program Sequence
CE#
SI
SCK
A[23:16] A[15:8] A[7:0]
AF Data Byte 1 AF DataByte2
CE#
SI
SO
SCK
Write Disable (WRDI)
Instruction to terminate
AAI Operation
Read Status Register (RDSR)
Instruction to verify end of
AAI Operation
04Last Data ByteAF 05
DOUT
MODE 3
MODE 0
TBP TBP
TBP
1231 F06.1
012345678 323334353637383915 16 23 24 31 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 01
012345670123456789101112131415 0123456789101112131415
©2011 Silicon Storage Technology, Inc. DS25078A 11/11
13
2 Mbit SPI Serial Flash
SST25VF020
Not Recommended for New Designs
A
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 [A23-A0]. Address bits [AMS-A12](A
MS = Most Significant address) are used to
determine the sector address (SAX), remaining address bits can be VIL or VIH. CE# must be driven high
before the instruction is executed. The user may poll the Busy bit in the software status register or wait
TSE for the completion of the internal self-timed Sector-Erase cycle. See Figure 8 for the Sector-Erase
sequence.
Figure 8: 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 [A23-A0]. Address bits [AMS-A15](A
MS = Most significant address) are used to deter-
mine block address (BAX), remaining address bits can be VIL or VIH. CE# must be driven high before the
instruction is executed. The user may poll the Busy bit in the software status register or wait TBE for the com-
pletion of the internal self-timed Block-Erase cycle. See Figure 9 for the Block-Erase sequence.
Figure 9: Block-Erase Sequence
CE#
SO
SI
SCK
ADD.
012345678
ADD. ADD.
20
HIGH IMPEDANCE
15 16 23 24 31
MODE 0
MODE 3
1231 F07.1
MSBMSB
CE#
SO
SI
SCK
ADD.
012345678
ADD. ADD.
52
HIGH IMPEDANCE
15 16 23 24 31
MODE 0
MODE 3
1231 F08.1
MSB MSB
©2011 Silicon Storage Technology, Inc. DS25078A 11/11
14
2 Mbit SPI Serial Flash
SST25VF020
Not Recommended for New Designs
A
Microchip Technology Company
Chip-Erase
The Chip-Erase instruction clears all bits in the device to FFH. A Chip-Erase instruction will be ignored
if any of the memory area is protected. Prior to any Write operation, the Write-Enable (WREN) instruction
must be executed. CE# must remain active low for the duration of the Chip-Erase instruction sequence.
The Chip-Erase instruction is initiated by executing an 8-bit command, 60H. CE# must be driven high
before the instruction is executed. The user may poll the Busy bit in the software status register or wait TCE
for the completion of the internal self-timed Chip-Erase cycle. See Figure 10 for the Chip-Erase
sequence.
Figure 10:Chip-Erase Sequence
Read-Status-Register (RDSR)
The Read-Status-Register (RDSR) instruction allows reading of the status register. The status register
may be read at any time even during a Write (Program/Erase) operation. When a Write operation is in
progress, the Busy bit may be checked before sending any new commands to assure that the new
commands are properly received by the device. CE# must be driven low before the RDSR instruction is
entered and remain low until the status data is read. Read-Status-Register is continuous with ongoing
clock cycles until it is terminated by a low to high transition of the CE#. See Figure 11 for the RDSR
instruction sequence.
Figure 11:Read-Status-Register (RDSR) Sequence
CE#
SO
SI
SCK
01234567
60
HIGH IMPEDANCE
MODE 0
MODE 3
1231 F09.1
MSB
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
1231 F10.1
MODE 3
SCK
SI
SO
CE#
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
05
MODE 0
HIGH IMPEDANCE
Status
Register Out
MSB
MSB
©2011 Silicon Storage Technology, Inc. DS25078A 11/11
15
2 Mbit SPI Serial Flash
SST25VF020
Not Recommended for New Designs
A
Microchip Technology Company
Write-Enable (WREN)
The Write-Enable (WREN) instruction sets the Write-Enable-Latch bit to 1 allowing Write operations to
occur. The WREN instruction must be executed prior to any Write (Program/Erase) operation. CE#
must be driven high before the WREN instruction is executed.
Figure 12:Write Enable (WREN) Sequence
Write-Disable (WRDI)
The Write-Disable (WRDI) instruction resets the Write-Enable-Latch bit and AAI bit to 0 disabling any
new Write operations from occurring. CE# must be driven high before the WRDI instruction is exe-
cuted.
Figure 13:Write Disable (WRDI) Sequence
Enable-Write-Status-Register (EWSR)
The Enable-Write-Status-Register (EWSR) instruction arms the Write-Status-Register (WRSR)
instruction and opens the status register for alteration. The Enable-Write-Status-Register instruction
does not have any effect and will be wasted, if it is not followed immediately by the Write-Status-Regis-
ter (WRSR) instruction. CE# must be driven low before the EWSR instruction is entered and must be
driven high before the EWSR instruction is executed.
CE#
SO
SI
SCK
01234567
06
HIGH IMPEDANCE
MODE 0
MODE 3
1231 F11.1
MSB
CE#
SO
SI
SCK
01234567
04
HIGH IMPEDANCE
MODE 0
MODE 3
1231 F12.1
MSB
©2011 Silicon Storage Technology, Inc. DS25078A 11/11
16
2 Mbit SPI Serial Flash
SST25VF020
Not Recommended for New Designs
A
Microchip Technology Company
Write-Status-Register (WRSR)
The Write-Status-Register instruction works in conjunction with the Enable-Write-Status-Register
(EWSR) instruction to write new values to the BP1, BP0, and BPL bits of the status register. The Write-
Status-Register instruction must be executed immediately after the execution of the Enable-Write-Sta-
tus-Register instruction (very next instruction bus cycle). This two-step instruction sequence of the
EWSR instruction followed by the WRSR instruction works like SDP (software data protection) com-
mand structure which prevents any accidental alteration of the status register values. The Write-Sta-
tus-Register instruction will be ignored when WP# is low and BPL bit is set to “1”. When the WP# is
low, the BPL bit can only be set from “0” to “1” to lock-down the status register, but cannot be reset
from “1” to “0”. When WP# is high, the lock-down function of the BPL bit is disabled and the BPL, BP0,
and BP1 bits in the status register can all be changed. As long as BPL bit is set to 0 or WP# pin is
driven high (VIH) prior to the low-to-high transition of the CE# pin at the end of the WRSR instruction,
the BP0, BP1, and BPL bit in the status register can all be altered by the WRSR instruction. In this
case, a single WRSR instruction can set the BPL bit to “1” to lock down the status register as well as
altering the BP0 and BP1 bit at the same time. See Table 2 for a summary description of WP# and BPL
functions. CE# must be driven low before the command sequence of the WRSR instruction is entered
and driven high before the WRSR instruction is executed. See Figure 14 for EWSR and WRSR instruc-
tion sequences.
Figure 14:Enable-Write-Status-Register (EWSR) and Write-Status-Register (WRSR)
Sequence
1231 F13.1
MODE 3
HIGH IMPEDANCE
MODE 0
STATUS
REGISTER IN
76543210
MSBMSBMSB
01
MODE 3
SCK
SI
SO
CE#
MODE 0
50
0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
©2011 Silicon Storage Technology, Inc. DS25078A 11/11
17
2 Mbit SPI Serial Flash
SST25VF020
Not Recommended for New Designs
A
Microchip Technology Company
Read-ID
The Read-ID instruction identifies the device as SST25VF020 and manufacturer as SST. The device
information can be read from executing an 8-bit command, 90H or ABH, followed by address bits [A23-
A0]. Following the Read-ID instruction, the manufacturer’s ID is located in address 00000H and the
device ID is located in address 00001H. Once the device is in Read-ID mode, the manufacturer’s and
device ID output data toggles between address 00000H and 00001H until terminated by a low to high
transition on CE#.
Figure 15:Read-ID Sequence
Table 6: Product Identification
Address Data
Manufacturer’s ID 00000H BFH
Device ID
SST25VF020 00001H 43H
T6.0 25078
1231 F14.1
CE#
SO
SI
SCK
00
012345678
00 ADD1
90 or AB
HIGH IMPEDANCE
15 16 23 24 31 32 39 40 47 48 55 56 63
BF Device ID BF Device ID
Note: The manufacturer s and device ID output stream is continuous until terminated by a low to high transition on CE#.
1. 00H will output the manfacturer s ID first and 01H will output device ID first before toggling between the two.
HIGH
IMPEDANCE
MODE 3
MODE 0
MSB MSB
MSB
©2011 Silicon Storage Technology, Inc. DS25078A 11/11
18
2 Mbit SPI Serial Flash
SST25VF020
Not Recommended for New Designs
A
Microchip Technology Company
Electrical Specifications
Absolute Maximum Stress Ratings (Applied conditions greater than those listed under “Absolute
Maximum Stress Ratings” may cause permanent damage to the device. This is a stress rating only and
functional operation of the device at these conditions or conditions greater than those defined in the
operational sections of this data sheet is not implied. Exposure to absolute maximum stress rating con-
ditions may affect device reliability.)
Temperature Under Bias .............................................. -55°C to +125°C
Storage Temperature................................................. -65°C to +150°C
D. C. Voltage on Any Pin to Ground Potential .............................-0.5V to VDD+0.5V
Transient Voltage (<20 ns) on Any Pin to Ground Potential ..................-2.0V to VDD+2.0V
Package Power Dissipation Capability (Ta = 25°C)................................... 1.0W
Surface Mount Solder Reflow Temperature ...........................260°C for 10 seconds
Output Short Circuit Current1................................................... 50mA
1. Output shorted for no more than one second. No more than one output shorted at a time.
Table 7: Operating Range
Range Ambient Temp VDD
Commercial 0°C to +70°C 2.7-3.6V
Industrial -40°C to +85°C 2.7-3.6V
Extended -20°C to +85°C 2.7-3.6V
T7.1 25078
Table 8: AC Conditions of Test1
1. See Figures 20 and 21
Input Rise/Fall Time Output Load
5ns CL=30pF
T8.1 25078
Table 9: DC Operating Characteristics VDD = 2.7-3.6V
Symbol Parameter
Limits
Test ConditionsMin Max Units
IDDR Read Current 10 mA CE#=0.1 VDD/0.9 VDD@20 MHz, SO=open
IDDW Program and Erase Current 30 mA CE#=VDD
ISB Standby Current 15 µA CE#=VDD,V
IN=VDD or VSS
ILI Input Leakage Current 1 µA VIN=GND to VDD,V
DD=VDD Max
ILO Output Leakage Current 1 µA VOUT=GND to VDD,V
DD=VDD Max
VIL Input Low Voltage 0.8 V VDD=VDD Min
VIH Input High Voltage 0.7 VDD VV
DD=VDD Max
VOL Output Low Voltage 0.2 V IOL=100 µA, VDD=VDD Min
VOH Output High Voltage VDD-0.2 V IOH=-100 µA, VDD=VDD Min
T9.0 25078
©2011 Silicon Storage Technology, Inc. DS25078A 11/11
19
2 Mbit SPI Serial Flash
SST25VF020
Not Recommended for New Designs
A
Microchip Technology Company
Table 10:Recommended System Power-up Timings
Symbol Parameter Minimum Units
TPU-READ1
1. This parameter is measured only for initial qualification and after a design or process change that could affect this
parameter.
VDD Min to Read Operation 10 µs
TPU-WRITE1VDD Min to Write Operation 10 µs
T10.0 25078
Table 11:Capacitance (Ta = 25°C, f=1 Mhz, other pins open)
Parameter Description Test Condition Maximum
COUT1
1. This parameter is measured only for initial qualification and after a design or process change that could affect this
parameter.
Output Pin Capacitance VOUT =0V 12pF
CIN1Input Capacitance VIN =0V 6pF
T11.0 25078
Table 12:Reliability Characteristics
Symbol Parameter Minimum Specification Units Test Method
NEND1
1. This parameter is measured only for initial qualification and after a design or process change that could affect this
parameter.
Endurance 10,000 Cycles JEDEC Standard A117
TDR1Data Retention 100 Years JEDEC Standard A103
ILTH1Latch Up 100 + IDD mA JEDEC Standard 78
T12.0 25078
©2011 Silicon Storage Technology, Inc. DS25078A 11/11
20
2 Mbit SPI Serial Flash
SST25VF020
Not Recommended for New Designs
A
Microchip Technology Company
Table 13:AC Operating Characteristics VDD = 2.7-3.6V
Symbol Parameter
Limits
Min Max Units
FCLK Serial Clock Frequency 20 MHz
TSCKH Serial Clock High Time 20 ns
TSCKL Serial Clock Low Time 20 ns
TSCKR Serial Clock Rise Time 5 ns
TSCKF Serial Clock Fall Time 5 ns
TCES1CE# Active Setup Time 20 ns
TCEH1CE# Active Hold Time 20 ns
TCHS1CE# Not Active Setup Time 10 ns
TCHH1CE# Not Active Hold Time 10 ns
TCPH CE# High Time 100 ns
TCHZ CE# High to High-Z Output 20 ns
TCLZ SCK Low to Low-Z Output 0 ns
TDS Data In Setup Time 4 ns
TDH Data In Hold Time 5 ns
THLS HOLD# Low Setup Time 10 ns
THHS HOLD# High Setup Time 10 ns
THLH HOLD# Low Hold Time 15 ns
THHH HOLD# High Hold Time 10 ns
THZ HOLD# Low to High-Z Output 20 ns
TLZ HOLD# High to Low-Z Output 20 ns
TOH Output Hold from SCK Change 0 ns
TVOutput Valid from SCK 23 ns
TSE Sector-Erase 25 ms
TBE Block-Erase 25 ms
TSCE Chip-Erase 100 ms
TBP Byte-Program 20 µs
T13.2 25078
1. Relative to SCK.
©2011 Silicon Storage Technology, Inc. DS25078A 11/11
21
2 Mbit SPI Serial Flash
SST25VF020
Not Recommended for New Designs
A
Microchip Technology Company
Figure 16:Serial Input Timing Diagram
Figure 17:Serial Output Timing Diagram
HIGH-Z HIGH-Z
CE#
SO
SI
SCK
MSB LSB
TDS TDH
TCHH TCES TCEH TCHS
TSCKR
TSCKF
TCPH
1231 F15.0
1231 F16.0
CE#
SI
SO
SCK
MSB
TCLZ
TV
TSCKH
TCHZ
TOH
TSCKL
LSB
©2011 Silicon Storage Technology, Inc. DS25078A 11/11
22
2 Mbit SPI Serial Flash
SST25VF020
Not Recommended for New Designs
A
Microchip Technology Company
Figure 18:Hold Timing Diagram
Figure 19:Power-up Timing Diagram
THZ TLZ
THHH THLS
THLH
THHS
1231 F17.0
HOLD#
CE#
SCK
SO
SI
Time
VDD Min
VDD Max
VDD
Device fully accessible
TPU-READ
TPU-WRITE
Chip selection is not allowed.
All commands are rejected by the device.
1231 F18.0
©2011 Silicon Storage Technology, Inc. DS25078A 11/11
23
2 Mbit SPI Serial Flash
SST25VF020
Not Recommended for New Designs
A
Microchip Technology Company
Figure 20:AC Input/Output Reference Waveforms
Figure 21:A Test Load Example
1231 F19.1
REFERENCE POINTS OUTPUTINPUT
VHT
VLT
VHT
VLT
VIHT
VILT
AC test inputs are driven at VIHT (0.9VDD) for a logic “1” and VILT (0.1VDD) for a logic “0”. Measure-
ment reference points for inputs and outputs are VHT (0.7VDD) and VLT (0.3VDD). Input rise and fall
times (10% 90%) are <5 ns.
Note: VHT -V
HIGH Test
VLT -V
LOW Test
VIHT -V
INPUT HIGH Test
VILT -V
INPUT LOW Test
1231 F20.0
TO TESTER
TO DUT
CL
©2011 Silicon Storage Technology, Inc. DS25078A 11/11
24
2 Mbit SPI Serial Flash
SST25VF020
Not Recommended for New Designs
A
Microchip Technology Company
Product Ordering Information
Valid combinations for SST25VF020
SST25VF020-20-4C-SAE SST25VF020-20-4C-QAE
SST25VF020-20-4I-SAE SST25VF020-20-4I-QAE
SST25VF020-20-4E-SAE SST25VF020-20-4E-QAE
Note:Valid combinations are those products in mass production or will be in mass production. Consult your SST
sales representative to confirm availability of valid combinations and to determine availability of new combi-
nations.
SST 25 VF 020 - 20 - 4I - QAE
XX XX XXX - XX - XX -XXX
Environmental Attribute
E1= non-Pb
Package Modifier
A = 8 leads or contacts
Package Type
S = SOIC 150 mil body width
Q = WSON
Temperature Range
C = Commercial = 0°C to +70°C
I = Industrial = -40°C to +85°C
E = Extended = -20°C to +85°C
Minimum Endurance
4 = 10,000 cycles
Operating Frequency
20 = 20 MHz
Device Density
020 = 2 Mbit
Voltage
V = 2.7-3.6V
Product Series
25 = Serial Peripheral Interface
flash memory
1. Environmental suffix “E” denotes non-Pb sol-
der. SST non-Pb solder devices are “RoHS
Compliant”.
©2011 Silicon Storage Technology, Inc. DS25078A 11/11
25
2 Mbit SPI Serial Flash
SST25VF020
Not Recommended for New Designs
A
Microchip Technology Company
Packaging Diagrams
Figure 22: 8-lead Small Outline Integrated Circuit (SOIC) 150 mil body width (4.9mm x 6mm)
SST Package Code: SA
08-soic-5x6-SA-8
Note: 1. Complies with JEDEC publication 95 MS-012 AA dimensions,
although some dimensions may be more stringent.
2. All linear dimensions are in millimeters (max/min).
3. Coplanarity: 0.1 mm
4. Maximum allowable mold flash is 0.15 mm at the package ends and 0.25 mm between leads.
TOP VIEW SIDE VIEW
END VIEW
5.0
4.8
6.20
5.80
4.00
3.80
Pin #1
Identifier
0.51
0.33
1.27 BSC
0.25
0.10
1.75
1.35
4 places
0.25
0.19
1.27
0.40
45°
4 places
1mm
©2011 Silicon Storage Technology, Inc. DS25078A 11/11
26
2 Mbit SPI Serial Flash
SST25VF020
Not Recommended for New Designs
A
Microchip Technology Company
Figure 23:8-contact Very-very-thin Small Outline No-lead (WSON)
SST Package Code: QA
Note: 1. All linear dimensions are in millimeters (max/min).
2. Untoleranced dimensions (shown with box surround)
are nominal target dimensions.
3. The external paddle is electrically connected to the
die back-side and possibly to certain VSS leads.
This paddle can be soldered to the PC board;
it is suggested to connect this paddle to the VSS of the unit.
Connection of this paddle to any other voltage potential can
result in shorts and/or electrical malfunction of the device.
8-wson-5x6-QA-9.0
4.0
1.27 BSC
Pin #1
0.48
0.35
0.076
3.4
5.00 ±0.10
6.00 ± 0.10 0.05 Max
0.70
0.50
0.80
0.70
0.80
0.70
Pin #1
Corner
TOP VIEW BOTTOM VIEW
CROSS SECTION
SIDE VIEW
1mm
0.2
©2011 Silicon Storage Technology, Inc. DS25078A 11/11
27
2 Mbit SPI Serial Flash
SST25VF020
Not Recommended for New Designs
A
Microchip Technology Company
Table 14:Revision History
Revision Description Date
00 Initial release of S71231
(2 Mbit and 4 Mbit parts were originally described in data sheet S71192)
Apr 2003
01 Updated Figures 3, 5 - 15: Aligned SI waveform with rising edge of clock Aug 2003
02 Added new 8-SOIC (S2A) package and associated MPNs Oct 2003
03 2004 Data Book
Updated the Package Outline for S2A
Dec 2003
04 Added Extended temperature and associated MPNs Jun 2004
05 Revised Absolute Max. Stress Ratings for Surface Mount Solder Reflow
Temp.
Nov 2005
06 Updated QA package drawing to revision 9.
Removed leaded parts.
Added footnote to product ordering section.
Jan 2006
07 Removed all references to SST25VF040 due to end of life. New
SST25VF040 EOL data sheet is S71231(04).
Revised Hold Operation, page 6 paragraph 4, to indicate that device
returns to standby mode when CE# is driven active high during a Hold
Condition.
Oct 2006
AApplied new document format
Released document under letter revision system
Updated spec number from S71231 to DS25078
Nov 2011
©
2011 Silicon Storage Technology, Inc–a Microchip Technology Company. All rights reserved.
SST, Silicon Storage Technology, the SST logo, SuperFlash, MTP, and FlashFlex are registered trademarks of Silicon Storage Tech-
nology, Inc. MPF, SQI, Serial Quad I/O, and Z-Scale are trademarks of Silicon Storage Technology, Inc. All other trademarks and
registered trademarks mentioned herein are the property of their respective owners.
Specifications are subject to change without notice. Refer to www.microchip.com for the most recent documentation. For the most current
package drawings, please see the Packaging Specification located at http://www.microchip.com/packaging.
Memory sizes denote raw storage capacity; actual usable capacity may be less.
SST makes no warranty for the use of its products other than those expressly contained in the Standard Terms and Conditions of
Sale.
For sales office locations and information, please see www.microchip.com.
Silicon Storage Technology, Inc.
A Microchip Technology Company
www.microchip.com
ISBN:978-1-61341-680-8