512 Kbit SPI Serial Flash
SST25VF512
A Microchip Technology Company
Data Sheet
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. SST25VF512 SPI serial flash memory is manufactured with
SST's proprietary, high-performance CMOS SuperFlash technology. The splitgate cell design and thick-oxide tunneling injector attain better reliability and manufacturability compared with alternate approaches.
Features
• Single 2.7-3.6V Read and Write Operations
• End-of-Write Detection
– Software Status
• Serial Interface Architecture
• Hold Pin (HOLD#)
– SPI Compatible: Mode 0 and Mode 3
– Suspends a serial sequence to the memory
without deselecting the device
• 20 MHz Max Clock Frequency
• Superior Reliability
• Write Protection (WP#)
– Endurance: 100,000 Cycles (typical)
– Greater than 100 years Data Retention
– Enables/Disables the Lock-Down function of the status
register
• Low Power Consumption:
• Software Write Protection
– Active Read Current: 7 mA (typical)
– Standby Current: 8 µA (typical)
– Write protection through Block-Protection bits in status
register
• Flexible Erase Capability
• Packages Available
– Uniform 4 KByte sectors
– Uniform 32 KByte overlay blocks
– 8-lead SOIC (4.9mm x 6mm)
– 8-contact WSON
• Fast Erase and Byte-Program:
• All non-Pb (lead-free) devices are RoHS compliant
– 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-Program operations
©2011 Silicon Storage Technology, Inc.
www.microchip.com
DS25076A
10/11
512 Kbit SPI Serial Flash
SST25VF512
A Microchip Technology Company
Data Sheet
Product Description
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. SST25VF512 SPI
serial flash memory is manufactured with SST’s proprietary, high-performance CMOS SuperFlash
technology. The split-gate cell design and thick-oxide tunneling injector attain better reliability and manufacturability compared with alternate approaches.
The SST25VF512 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 SST25VF512 device operates with a single 2.7-3.6V power supply.
The SST25VF512 device is offered in both 8-lead SOIC and 8-contact WSON packages. See Figure 1
for the pin assignments.
©2011 Silicon Storage Technology, Inc.
DS25076A
2
10/11
512 Kbit SPI Serial Flash
SST25VF512
A Microchip Technology Company
Data Sheet
Block Diagram
SuperFlash
Memory
X - Decoder
Address
Buffers
and
Latches
Y - Decoder
I/O Buffers
and
Data Latches
Control Logic
Serial Interface
1192 B1.5
CE#
SCK
©2011 Silicon Storage Technology, Inc.
SI
SO
WP#
HOLD#
DS25076A
3
10/11
512 Kbit SPI Serial Flash
SST25VF512
A Microchip Technology Company
Data Sheet
Pin Description
CE#
1
8
VDD
SO
2
7
HOLD#
CE#
1
SO
2
8
VDD
7
HOLD#
Top View
Top View
WP#
3
6
SCK
WP#
3
6
SCK
VSS
4
5
SI
VSS
4
5
SI
1192 08-soic P1.4
1192 08-wson P1a.6
8-lead SOIC
8-contact WSON
Figure 1: 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
T1.7 25076
©2011 Silicon Storage Technology, Inc.
DS25076A
4
10/11
512 Kbit SPI Serial Flash
SST25VF512
A Microchip Technology Company
Data Sheet
Memory Organization
The SST25VF512 SuperFlash memory array is organized in 4 KByte sectors with 32 KByte overlay
blocks.
Device Operation
The SST25VF512 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 SST25VF512 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 2, 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.
CE#
SCK
SI
MODE 3
MODE 3
MODE 0
MODE 0
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
MSB
SO
HIGH IMPEDANCE
DON T CARE
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
MSB
1192 F34.6
Figure 2: SPI Protocol
©2011 Silicon Storage Technology, Inc.
DS25076A
5
10/11
512 Kbit SPI Serial Flash
SST25VF512
A Microchip Technology Company
Data Sheet
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 3 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 resets the internal logic of the device. 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 17 for Hold timing.
SCK
HOLD#
Active
Hold
Active
Hold
Active
1192 F44.0
Figure 3: Hold Condition Waveform
Write Protection
The SST25VF512 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 3 for BlockProtection 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 25076
©2011 Silicon Storage Technology, Inc.
DS25076A
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10/11
512 Kbit SPI Serial Flash
SST25VF512
A Microchip Technology Company
Data Sheet
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 protection. During an internal Erase or Program operation, the status register may be read only to determine the completion of an operation in progress. Table 4 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
Block Protection (BP1, BP0)
The Block-Protection (BP1, BP0) bits define the size of the memory area, as defined in Table 3, to be
software protected against any memory Write (Program or Erase) operations. The Write-Status-Register (WRSR) instruction is used to program the BP1 and BP0 bits as long as WP# is high or the BlockProtect-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.
©2011 Silicon Storage Technology, Inc.
DS25076A
7
10/11
512 Kbit SPI Serial Flash
SST25VF512
A Microchip Technology Company
Data Sheet
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.
Table 3: Software Status Register Block Protection1
Status
Register Bit
Protected
Memory Area
Protection Level
BP1
BP0
0
0
0
None
1
(1/4 Memory Array)2
0
1
0C000H-0FFFFH
2
(1/2 Memory Array)
1
0
08000H-0FFFFH
3
(Full Memory Array)
1
1
00000H-0FFFFH
T3.5 25076
1. Default at power-up for BP1 and BP0 is ‘11’.
2. Protection Level 1 (1/4 Memory Array) applies to Byte-Program, Sector-Erase, and Chip-Erase operations.
It does not apply to Block-Erase operations.
Table 4: 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
0
R
1
WEL
1 = Device is memory Write enabled
0 = Device is not memory Write enabled
0
R
2
BP0
Indicate current level of block write protection (See Table 3)
1
R/W
3
BP1
Indicate current level of block write protection (See Table 3)
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
0
R
7
BPL
1 = BP1, BP0 are read-only bits
0 = BP1, BP0 are read/writable
0
R/W
T4.0 25076
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.
©2011 Silicon Storage Technology, Inc.
DS25076A
8
10/11
512 Kbit SPI Serial Flash
SST25VF512
A Microchip Technology Company
Data Sheet
Instructions
Instructions are used to Read, Write (Erase and Program), and configure the SST25VF512. 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 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
Bus Cycle2
Type/Operation3,4
1
2
3
4
5
SIN
SOUT
SIN
SOUT
SIN
SOUT
SIN
SOUT
SIN
SOUT
Read
03H
Hi-Z
A23-A16
Hi-Z
A15-A8
Hi-Z
A7-A0
Hi-Z
X
DOUT
Sector-Erase5,6
20H
Hi-Z
A23-A16
Hi-Z
A15-A8
Hi-Z
A7-A0
Hi-Z
-
-
Block-Erase5,7
52H
Hi-Z
A23-A16
Hi-Z
A15-A8
Hi-Z
A7-A0
Hi-Z
-
-
Chip-Erase6
60H
Hi-Z
-
-
-
-
-
-
-
-
Byte-Program6
02H
Hi-Z
A23-A16
Hi-Z
A15-A8
Hi-Z
A7-A0
Hi-Z
DIN
Hi-Z
Auto Address Increment
(AAI) Program6,8
AFH
Hi-Z
A23-A16
Hi-Z
A15-A8
Hi-Z
A7-A0
Hi-Z
DIN
Hi-Z
Read-Status-Register
(RDSR)
05H
Hi-Z
X
DOUT
-
Note9
-
Note9
-
Note9
Enable-Write-Status-Register (EWSR)10
50H
Hi-Z
-
-
-
-
-
-
-
-
Write-Status-Register
(WRSR)10
01H
Hi-Z
Data
Hi-Z
-
-
-.
-
-
-
Cycle
Write-Enable (WREN)
06H
Hi-Z
-
-
-
-
-
-
-
-
Write-Disable (WRDI)
04H
Hi-Z
-
-
-
-
-
-
-
-
90H or
ABH
Hi-Z
00H
Hi-Z
00H
Hi-Z
ID
Addr11
Hi-Z
X
DOUT12
Read-ID
T5.18 25076
1. AMS = Most Significant Address
AMS = A15 for SST25VF512
Address bits above the most significant bit of each density can be VIL or VIH
2. One bus cycle is eight clock periods.
3. Operation: SIN = Serial In, SOUT = Serial Out
4. X = Dummy Input Cycles (VIL or VIH); - = Non-Applicable Cycles (Cycles are not necessary)
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.
©2011 Silicon Storage Technology, Inc.
DS25076A
9
10/11
512 Kbit SPI Serial Flash
SST25VF512
A Microchip Technology Company
Data Sheet
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 = 48H for SST25VF512
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 4 Mbit density, once the data from address location 7FFFFH 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 [A23A0]. CE# must remain active low for the duration of the Read cycle. See Figure 4 for the Read
sequence.
CE#
MODE 3
SCK
0 1 2 3 4 5 6 7 8
ADD.
ADD.
03
SI
MSB
MSB
SO
15 16
23 24
31 32
39 40
47
48
55 56
63 64
70
MODE 0
HIGH IMPEDANCE
ADD.
N
DOUT
N+1
DOUT
N+2
DOUT
N+3
DOUT
N+4
DOUT
MSB
1192 F10.11
Figure 4: Read Sequence
©2011 Silicon Storage Technology, Inc.
DS25076A
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512 Kbit SPI Serial Flash
SST25VF512
A Microchip Technology Company
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 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 executed. 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 5 for the Byte-Program sequence.
CE#
MODE 3
SCK
0 1 2 3 4 5 6 7 8
15 16
23 24
31 32
39
MODE 0
02
SI
ADD.
ADD.
MSB
MSB
SO
ADD.
DIN
MSB
LSB
HIGH IMPEDANCE
1192 F08.11
Figure 5: Byte-Program Sequence
©2011 Silicon Storage Technology, Inc.
DS25076A
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10/11
512 Kbit SPI Serial Flash
SST25VF512
A Microchip Technology Company
Data Sheet
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 memory 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]. Following 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 programmed, 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 6 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).
TBP
TBP
CE#
MODE 3
SCK
SI
0 1 2 3 4 5 6 7 8
15 16
23 24
31 32 33 34 35 36 37 38 39
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
0 1
MODE 0
AF
A[23:16] A[15:8]
Data Byte 1
A[7:0]
AF
Data Byte 2
TBP
CE#
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
0 1 2 3 4 5 6 7
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
SCK
SI
AF
Last Data Byte
04
Write Disable (WRDI)
Instruction to terminate
AAI Operation
05
Read Status Register (RDSR)
Instruction to verify end of
AAI Operation
SO
DOUT
1192 F39.10
Figure 6: Auto Address Increment (AAI) Program Sequence
©2011 Silicon Storage Technology, Inc.
DS25076A
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10/11
512 Kbit SPI Serial Flash
SST25VF512
A Microchip Technology Company
Data Sheet
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 WriteEnable (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, followed by address bits [A23-A0]. Address bits [AMS-A12] (AMS = 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 7 for the Sector-Erase
sequence.
CE#
MODE 3
SCK
0 1 2 3 4 5 6 7 8
15 16
23 24
31
MODE 0
20
SI
MSB
ADD.
ADD.
ADD.
MSB
SO
HIGH IMPEDANCE
1192 F06.12
Figure 7: Sector-Erase Sequence
©2011 Silicon Storage Technology, Inc.
DS25076A
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10/11
512 Kbit SPI Serial Flash
SST25VF512
A Microchip Technology Company
Data Sheet
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 WriteEnable (WREN) instruction must be executed. CE# must remain active low for the duration of any command sequence. The Block-Erase instruction is initiated by executing an 8-bit command, 52H, followed
by address bits [A23-A0]. Address bits [AMS-A15] (AMS = Most significant address) are used to determine 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 completion of the internal self-timed Block-Erase cycle. See Figure 8 for the Block-Erase sequence.
CE#
MODE 3
SCK
0 1 2 3 4 5 6 7 8
15 16
23 24
31
MODE 0
ADD.
52
SI
MSB
ADD.
ADD.
MSB
SO
HIGH IMPEDANCE
1192 F28.11
Figure 8: Block-Erase Sequence
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 9 for the Chip-Erase
sequence.
CE#
MODE 3
SCK
0 1 2 3 4 5 6 7
MODE 0
60
SI
MSB
SO
HIGH IMPEDANCE
1192 F07.12
Figure 9: Chip-Erase Sequence
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DS25076A
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512 Kbit SPI Serial Flash
SST25VF512
A Microchip Technology Company
Data Sheet
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 10 for the RDSR
instruction sequence.
CE#
MODE 3
SCK
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
MODE 0
05
SI
MSB
SO
HIGH IMPEDANCE
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
MSB
Status
Register Out
1192 F37.7
Figure 10:Read-Status-Register (RDSR) Sequence
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.
CE#
MODE 3
SCK
0 1 2 3 4 5 6 7
MODE 0
06
SI
MSB
SO
HIGH IMPEDANCE
1192 F35.6
Figure 11:Write Enable (WREN) Sequence
©2011 Silicon Storage Technology, Inc.
DS25076A
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10/11
512 Kbit SPI Serial Flash
SST25VF512
A Microchip Technology Company
Data Sheet
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 executed.
CE#
MODE 3
SCK
0 1 2 3 4 5 6 7
MODE 0
04
SI
MSB
SO
HIGH IMPEDANCE
1192 F36.6
Figure 12: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-Register (WRSR) instruction. CE# must be driven low before the EWSR instruction is entered and must be
driven high before the EWSR instruction is executed.
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512 Kbit SPI Serial Flash
SST25VF512
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Data Sheet
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 WriteStatus-Register instruction must be executed immediately after the execution of the Enable-Write-Status-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) command structure which prevents any accidental alteration of the status register values. The Write-Status-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 13 for EWSR and WRSR instruction sequences.
CE#
MODE 3
SCK
0 1 2 3 4 5 6 7
MODE 3
MODE 0
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
MODE 0
01
50
SI
MSB
MSB
STATUS
REGISTER IN
7 6 5 4 3 2 1 0
MSB
HIGH IMPEDANCE
SO
1192 F38.9
Figure 13:Enable-Write-Status-Register (EWSR) and Write-Status-Register (WRSR)
Sequence
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DS25076A
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512 Kbit SPI Serial Flash
SST25VF512
A Microchip Technology Company
Data Sheet
Read-ID
The Read-ID instruction identifies the device as SST25VF512 and manufacturer as SST. The device
information can be read from executing an 8-bit command, 90H or ABH, followed by address bits [A23A0]. 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#.
Table 6: Product Identification
Manufacturer’s ID
Address
Data
00000H
BFH
00001H
48H
Device ID
SST25VF512
T6.5 25076
CE#
MODE 3
SCK
0 1 2 3 4 5 6 7 8
90 or AB
SI
00
00
MSB
SO
23 24
15 16
31 32
39 40
47 48
55 56
63
MODE 0
ADD1
MSB
HIGH IMPEDANCE
BF
Device ID
BF
Device ID
HIGH
IMPEDANCE
MSB
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.
1192 F19.15
Figure 14:Read-ID Sequence
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512 Kbit SPI Serial Flash
SST25VF512
A Microchip Technology Company
Data Sheet
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 conditions 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 (