Rainbow Electronics AT45DB161D - Manual (Page 23)

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3500O–DFLASH–11/2012
AT45DB161D
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 vendor 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 outputting 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
Note: Based on JEDEC publication 106 (JEP106), Manufacturer ID data can be comprised of any number of bytes. Some manufacturers
may have Manufacturer ID codes that are two, three or even four bytes long with the first byte(s) in the sequence being 7FH. A system
should detect code 7FH as a “Continuation Code” and continue to read Manufacturer ID bytes. The first non-7FH byte would signify
the last byte of Manufacturer ID data. For Adesto (and some other manufacturers), the Manufacturer ID data is comprised of only one
byte.
Hex
Value
JEDEC Assigned Code
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
1FH 0 0 0 1 1 1 1 1 Manufacturer ID 1FH = Adesto
Hex
Value
Family Code Density Code
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Family Code 001 = DataFlash
26H 0 0 1 0 0 1 1 0 Density Code 00110 = 16-Mbit
Hex
Value
MLC Code Product Version Code
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 MLC Code 000 = 1-bit/Cell Technology
00H 0 0 0 0 0 0 0 0 Product Version 00000 = Initial Version
Hex
Value
Byte Count
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
9FH
Manufacturer ID
Byte 1
Device ID
Byte 2
Device ID
Byte 3
This information would only be output
if the Extended Device Information String Length
value was something other than 00H.
Extended
Device
Information
String Length
Extended
Device
Information
Byte x
Extended
Device
Information
Byte x + 1
CS
1FH 26H 00H 00H Data Data
SI
SO
Opcode
Each transition
represents 8 bits