SST25PF040B
DS20005134B-page 16 2014 Microchip Technology Inc.
4.4.15 JEDEC READ-ID
The JEDEC Read-ID instruction identifies the device as
SST25PF040B and the manufacturer as Microchip.
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 manufac-
turer as Microchip. Byte 2, 25H, identifies the memory
type as SPI Serial Flash. Byte 3, 8DH, identifies the
device as SST25PF040B. The instruction sequence is
shown in Figure 4-18. The JEDEC Read ID instruction
is terminated by a low to high transition on CE# at any
time during data output.
FIGURE 4-18: JEDEC READ-ID SEQUENCE
4.4.16 READ-ID (RDID)
The Read-ID instruction (RDID) identifies the devices
as SST25PF040B and manufacturer as Microchip. This
command is backward compatible to all SST25xFxxxA
devices and should be used as default device identifi-
cation when multiple versions of SPI Serial Flash
devices are used in a design. The device information
can be read from executing an 8-bit command, 90H or
ABH, followed by address bits [A
23
-A
0
]. 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#.
Refer to Tables 4-5 and 4-6 for device identification
data.
TABLE 4-5: JEDEC READ-ID DATA
Manufacturer’s ID Device ID
Memory Type Memory Capacity
Byte1 Byte 2 Byte 3
BFH 25H 8DH
25 8D
25134 JEDECID.1
CE#
SO
SI
SCK
012345678
HIGH IMPEDANCE
15 1614 28 29 30 31
BF
MODE 3
MODE 0
MSBMSB
9 10111213 1718 32 34
9F
19 20 21 22 23 3324 25 26 27
TABLE 4-6: PRODUCT IDENTIFICATION
Address Data
Manufacturer’s ID 00000H BFH
Device ID 00001H 8DH
