23

3599F–DFLASH–09/06

AT26DF161

11. Other Commands and Functions

11.1

Read Manufacturer and Device ID

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. After the Extended Device Information

String Length byte is output, the SO pin will go into a high-impedance state; therefore, additional

clock cycles will have no affect on the SO pin and no data will be output. 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.

Table 11-1.

Manufacturer and Device ID Information

Byte No.

Data Type

Value

1

Manufacturer ID

1Fh

2

Device ID (Part 1)

46h

3

Device ID (Part 2)

00h

4

Extended Device Information String Length

00h

Table 11-2.

Manufacturer and Device ID Details

Data Type

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

Hex

Value

Details

Manufacturer ID

JEDEC Assigned Code

1Fh

JEDEC Code:

0001 1111 (1Fh for Atmel)

00

011

111

Device ID (Part 1)

Family Code

Density Code

46h

Family Code:

Density Code:

010 (AT26DFxxx series)

00110 (16-Mbit)

01

000

110

Device ID (Part 2)

MLC Code

Product Version Code

00h

MLC Code:

Product Version:

000 (1-bit/cell technology)

00000 (Initial version)

00

000

000