Uniform Sector

Standard and Dual Serial Flash

GD25WD40C/20C

23

command will be accepted. If the Release from Power-Down and Read Device ID command is issued while an Erase,

Program or Write cycle is in process (when WIP equal 1) the command is ignored and will not have any effects on the

current cycle.

Figure14. Release Power-Down Sequence Diagram

Figure15. Release Power-Down and Read Device ID Sequence Diagram

7.15.

Read Manufacture ID/ Device ID (REMS) (90H)

The Read Manufacturer/Device ID command is an alternative to the Release from Power-Down / Device ID command

that provides both the JEDEC assigned Manufacturer ID and the specific Device ID.

The command is initiated by driving the CS# pin low and shifting the command code “90H” followed by a 24-bit address

(A23-A0) of 000000H. After that, the Manufacturer ID and the Device ID are shifted out on the falling edge of SCLK with

most significant bit (MSB) first as shown in Figure16. If the 24-bit address is initially set to 000001H, the Device ID will be

read first.

Command

0

1

2

3

4

5

6

7

ABH

CS#

SCLK

SI

8

9

29 30 31

MSB

2

1

0

3 Dummy Bytes

23 22

32 33 34 35 36 37 38

7

6

5

4

3

2

1

0

SO

MSB

Stand-by Mode

Deep Power-down Mode

High-Z

Device ID

Command

0

1

2

3

4

5

6

7

ABH

CS#

SCLK

SI

RES1

Stand-by mode

Deep Power-down mode

t