23

AT25DF512C

DS-25DF512C–030E–2/2017

Figure 12-1. Read Manufacturer and Device ID

12.2 Read ID (Legacy Command)

Identification information can be read from the device to enable systems to electronically query and identify the device

while it is in system. The preferred method for doing so is the JEDEC standard “Read Manufacturer and Device ID”

method described in Section 12.1 on page 22; however, the legacy Read ID command is supported on the AT25DF512C

to enable backwards compatibility to previous generation devices.

To read the identification information, the CS pin must first be asserted and the opcode of 15h 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 of 1Fh followed by a single byte

of data representing a device code of 65h. After the device code is output, the SO pin will go into a high-impendance

state; therefore, additional clock cycles will have no affect on the SO pin and no data will be output.

Deasserting the CS pin will terminate the Read ID 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 read.

Table 12-2. Manufacturer and Device ID Details

Data Type

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

Hex

Valu

e

Details

Manufacturer ID

JEDEC Assigned Code

1Fh

JEDEC Code: 0001 1111 (1Fh for Adesto)

0

0

0

1

1

1

1

1

Device ID (Part

1)

Family Code

Density Code

65h

Family Code: 011 (AT25F/AT25FSxxx series)

Density Code: 00101 (512-Kbit)

0

1

1

0

0

1

0

1

Device ID (Part

2)

Sub Code

Product Version Code

01h

Sub Code:

000 (Standard series)

Product Version:00001

0

0

0

0

0

0

0

1

SCK

CS

SI

SO

6

0

9Fh

8

7

38

OPCODE

1Fh

65h

01h

00h

MANUFACTURER ID

DEVICE ID

BYTE1

DEVICE ID

BYTE2

EXTENDED

DEVICE

INFORMATION

STRING LENGTH

HIGH-IMPEDANCE

14

16

15

22

24

23

30

32

31

Note: Each transition

shown for SI and SO represents one byte (8 bits)