Document Number: 002-00646 Rev. *M

Page 19 of 45

S25FL128P

11.4

Read Manufacturer and Device ID (READ_ID: 90h)

11.4.1

Serial Mode

The READ_ID (90h) instruction identifies the Device Manufacturer ID and the Device ID. The instruction is initiated by driving the

CS# pin low and shifting in (via the SI input pin) the instruction code “90h” followed by a 24-bit address of XXXXX0h. (X: High or

Low) Following this, the Manufacturer ID and the Device ID are shifted out on SO output pin starting after the falling edge of the SCK

serial clock input signal. The Manufacturer ID and the Device ID are always shifted out on the SO output pin with the MSB first, as

shown in Figure 11.6. If the 24-bit address is set to XXXXX1h, then the Device ID is read out first followed by the Manufacturer ID.

Note that the upper 23 bits of the address do not have to be 0’s and can be don’t cares. Once the device is in READ_ID mode, the

Manufacturer ID and Device ID output data toggles between address 000000H and 000001H until terminated by a low to high

transition on the CS# input pin. After the first 24-bit address is provided, the user must wait 16 clock cycles for both the Manufacturer

ID and Device ID to be output on the SO output pin. The maximum clock frequency for the READ_ID (90h) command is at 104MHz

(Fast Read). Parallel Mode the maximum clock frequency is 10 MHz.

The Manufacturer ID & Device ID is output continuously until terminated by a low to high transition on CS# chip select input pin.

After issuing READ_ID instruction, driving the CS# chip select input pin to the logic high state will automatically send the device into

the standby mode. Driving the CS# chip select input pin to the logic low state again will automatically send the device out of the

standby mode and into the active mode.

Figure 11.6 Serial READ_ID Instruction Sequence

Table 11.1 Manufacturer & Device Identification, RDID (9Fh)

Device

Manufacturer Identification

Device Identification

Extended Device Identification

Byte 0

Byte 1

Byte 2

Byte 3

Byte 4

Uniform 256 KB Sector

01h

20h

18h

03h

00h

Uniform 64 KB Sector

01h

20h

18h

03h

01h

CS#

SCK

SI

SO

High Impedance

24-Bit Address

High Impedance

Instruction

90h

01234567

23

22

21

20

19

18

17

16

8

9

10

11

12

13

14

15

15

14

13

12

11

10

9

8

16

17

18

19

20

21

22

23

CS#

SCK

SI

SO

High Impedance

Manufacturer ID

Device ID

24-Bit Address

MSB

MSB

76543210

765432107654321

0

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

47