Rainbow Electronics AT45DB321D - Manual (Page 26)

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3597J–DFLASH–4/08
AT45DB321D
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
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 = Atmel
14.1.2 Byte 2 – Device ID (Part 1)
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
27H 0 0 1 0 0 1 1 1 Density Code 00111 = 32-Mbit
14.1.3 Byte 3 – Device ID (Part 2)
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 1 Product Version 00001 = Second Version
14.1.4 Byte 4 – Extended Device Information String Length
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