14. Manufacturer and Device ID Read
Identification information can be read from the device to enable systems to electronically query
and identify the device while it is in system. The identification method and the command opcode
comply with the JEDEC standard for “Manufacturer and Device ID Read Methodology for SPI
Compatible Serial Interface Memory Devices”. The type of information that can be read from the
device includes the JEDEC defined Manufacturer ID, the vendor specific Device ID, and the ven-
dor specific Extended Device Information.
To read the identification information, the CS pin must first be asserted and the opcode of 9FH
must be clocked into the device. After the opcode has been clocked in, the device will begin out-
putting the identification data on the SO pin during the subsequent clock cycles. The first byte
that will be output will be the Manufacturer ID followed by two bytes of Device ID information.
The fourth byte output will be the Extended Device Information String Length, which will be 00H
indicating that no Extended Device Information follows. As indicated in the JEDEC standard,
reading the Extended Device Information String Length and any subsequent data is optional.
Deasserting the CS pin will terminate the Manufacturer and Device ID Read operation and put
the SO pin into a high-impedance state. The CS pin can be deasserted at any time and does not
require that a full byte of data be read.
14.1 Manufacturer and Device ID Information
14.1.1
Byte 1 – Manufacturer ID
JEDEC Assigned Code
Hex
Value
Bit 7
0
Bit 6
0
Bit 5
0
Bit 4
1
Bit 3
1
Bit 2
1
Bit 1
1
Bit 0
1
1FH
Manufacturer ID
1FH = Atmel
14.1.2
Byte 2 – Device ID (Part 1)
Family Code
Density Code
Hex
Value
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Family Code
001 = DataFlash
25H
0
0
1
0
0
1
0
1
Density Code
00101 = 8-Mbit
14.1.3
Byte 3 – Device ID (Part 2)
MLC Code
Product Version Code
Hex
Value
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
MLC Code
000 = 1-bit/Cell Technology
00000 = Initial Version
00H
0
0
0
0
0
0
0
0
Product Version
14.1.4
Byte 4 – Extended Device Information String Length
Byte Count
Hex
Value
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
00H
0
0
0
0
0
0
0
0
Byte Count
00H = 0 Bytes of Information
CS
9FH
Opcode
SI
1FH
25H
00H
00H
Data
Data
SO
Manufacturer ID
Byte n
Device ID
Byte 1
Device ID
Byte 2
Extended
Device
Information
String Length
Extended
Device
Information
Byte x
Extended
Device
Information
Byte x + 1
Each transition
represents 8 bits
This information would only be output
if the Extended Device Information String Length
value was something other than 00H.
26
AT45DB081D
3596L–DFLASH–04/09
ATMEL [ ATMEL ]
