Datasheet

©2013 Silicon Storage Technology, Inc. DS20005054C 04/13
23
2 Mbit SPI Serial Flash
SST25VF020B
Data Sheet
Figure 21:Enable-Write-Status-Register (EWSR) or Write-Enable (WREN) and
Write-Status-Register (WRSR) Word-Data Input Sequence
The WRSR instruction can either execute a byte-data or a word-data input. Extra data/clock input, or
within byte-/word-data input, will not be executed. The reason for the byte support is for backward com-
patibility to products where WRSR instruction sequence is followed by only a byte-data.
JEDEC Read-ID
The JEDEC Read-ID instruction identifies the device as SST25VF020B and the manufacturer as SST.
The device information can be read from executing the 8-bit command, 9FH. Following the JEDEC
Read-ID instruction, the 8-bit manufacturer’s ID, BFH, is output from the device. After that, a 16-bit
device ID is shifted out on the SO pin. Byte 1, BFH, identifies the manufacturer as SST. Byte 2, 25H,
identifies the memory type as SPI Serial Flash. Byte 3, 8CH, identifies the device as SST25VF020B.
The instruction sequence is shown in Figure 22. The JEDEC Read ID instruction is terminated by a low
to high transition on CE# at any time during data output.
Figure 22:JEDEC Read-ID Sequence
Table 7: JEDEC Read-ID Data
Device ID
Manufacturer’s ID Memory Type Memory Capacity
Byte1 Byte 2 Byte 3
BFH 25H 8CH
T7.0 25054
1417 EWSR1.0
MODE 3
HIGH IMPEDANCE
MODE 0
STATUS
REGISTER
76543210
MSBMSBMSB
01
MODE 3
SCK
SI
SO
CE#
MODE 0
50 or 06
0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
STATUS
REGISTER 1
76543210
MSB
16 17 18 19 20 21 22 23
25 8C
1417 JEDECID.1
CE#
SO
SI
SCK
012345678
HIGH IMPEDANCE
15 1614 28 29 30 31
BF
MODE 3
MODE 0
MSBMSB
9 10111213 1718
9F
19 20 21 22 23 24 25 26 27