SST25VF020B_11 Datasheet, PDF (7/35 Pages) Microchip Technology – 2 Mbit SPI Serial Flash

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2 Mbit SPI Serial Flash
SST25VF020B
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 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.
Table 3: Software Status Register
Bit Name
0 BUSY
1 WEL
2 BP0
3 BP1
4:5 RES
6 AAI
7 BPL
Function
1 = Internal Write operation is in progress
0 = No internal Write operation is in progress
1 = Device is memory Write enabled
0 = Device is not memory Write enabled
Indicates current level of block write protection (See Table
5)
Indicates current level of block write protection (See Table
5)
Reserved for future use
Auto Address Increment Programming status
1 = AAI programming mode
0 = Byte-Program mode
1 = BP1, BP0 are read-only bits
0 = BP1, BP0 are read/writable
Default at
Power-up
0
0
1
1
0
0
0
Read/Write
R
R
R/W
R/W
N/A
R
R/W
T3.0 1417
Software Status Register 1
The Software Status Register 1 is an additional register that contains Top Sector and Bottom Sector
Protection bits. These register bits are read/writable and determine the lock and unlock status of the
top and bottom sectors.
Table 4 describes the function of each bit in the Software Status Register 1.
Table 4: Software Status Register 1
Bit Name
0:1 RES
2 TSP
3 BSP
4:7 RES
Function
Reserved for future use
Top Sector Protection status
1 = Indicates highest sector is write locked
0 = Indicates highest sector is Write accessible
Bottom Sector Protection status
1 = Indicates lowest sector is write locked
0 = Indicates lowest sector is Write accessible
Reserved for future use
Default at
Power-up
0
0
Read/Write
N/A
R/W
0
R/W
0
N/A
T4.0 1417
©2011 Silicon Storage Technology, Inc.
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02/11