GD25Q21 datasheet(37/49 Pages) ELM

37 / 49 page

Rev.1.1

49 -

http://www.elm-tech.com

GD25Q21BxIGx Uniform Sector Dual and Quad Serial Flash

Figure 33. Erase Security Registers command Sequence Diagram

Command

0 1 2 3 4 5 6 7

44H

CS#

SCLK

8 9

29 30 31

MSB

2 1 0

24 Bits Address

23 22

7.29. Program Security Registers (42H)

The Program Security Registers command is similar to the Page Program command. It allows from 1 to 512

bytes Security Registers data to be programmed. A Write Enable (WREN) command must previously have been

executed to set the Write Enable Latch (WEL) bit before sending the Program Security Registers command. The

Program Security Registers command is entered by driving CS# Low, followed by the command code (42H),

three address bytes and at least one data byte on SI. As soon as CS# is driven high, the self-timed Program

Security Registers cycle (whose duration is tPP) is initiated. While the Program Security Registers cycle is in

progress, the Status Register may be read to check the value of the Write in Progress (WIP) bit. The Write in

Progress (WIP) bit is 1 during the self-timed Program Security Registers cycle, and is 0 when it is completed. At

some unspecified time before the cycle is completed, the Write Enable Latch (WEL) bit is reset.

If the Security Registers Lock Bit (LB3-1) is set to 1, the Security Registers will be permanently locked.

Program Security Registers command will be ignored.

Address

A23-16

A15-12

A11-9

A8-0

Security Register #1

00H

0 0 0 1

0 0 0

Byte Address

Security Register #2

00H

0 0 1 0

0 0 0

Byte Address

Security Register #3

00H

0 0 1 1

0 0 0

Byte Address

Figure 34. Program Security Registers command Sequence Diagram

Command

0 1 2 3 4 5 6 7

42H

CS#

SCLK

8 9 10

28 29 30 31

3 2 1 0

23 22 21

24-bit address

42 43 44 45

46 47

50 51 52 53

54 55

6 5 4 3 2 1 0

CS#

SCLK

MSB

Data Byte 2

32 33 34 35

7 6 5 4 3 2 1 0

MSB

6 5 4 3 2 1 0

Data Byte 1

Data Byte 3

Data Byte 256

MSB

36 37 38 39

GD25Q21 Datasheet(PDF) 37 Page - ELM Electronics

GD25Q21 Datasheet(HTML) 37 Page - ELM Electronics

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49

Datasheet Download

Link URL