SPI Flash Chip - Atmel(AT25DF021) Command List

Command Listing

Command		Opcode	Address Bytes		Dummy Bytes		Data Bytes
Read Commands
Read Array		0Bh(0000 1011B)	3		1		1+
Read Array (Low Frequency)		03h(0000 0011B)	3		0		1+
Program and Erase Commands
Block Erase (4 Kbytes)		20h(0010 0000B)	3		0		0
Block Erase (32 Kbytes)		52h(0101 0010B)	3		0		0
Block Erase (64 Kbytes)		D8h(1101 1000B)	3		0		0
Chip Erase		60h(0110 0000B)	0		0		0
		C7h(1100 0111B)	0		0		0
Byte/Page Program (1 to 256 Bytes)		02h(0000 0010B)	3		0		1+
Protection Commands
Write Enable		06h(0000 0110B)	0		0		0
Write Disable		04h(0000 0100B)	0		0		0
Protect Sector		36h(0011 0110B)	3		0		0
Unprotect Sector		39h(0011 1001B)	3		0		0
Global Protect/Unprotect		Use Write Status Register command
Read Sector Protection Registers		3Ch(0011 1100B)	3		0		1+
Security Commands
Program OTP Security Register	9Bh(1001 1011B)			3		0	1+
Read OTP Security Register	77h(0111 0111B)			3		2	1+
Status Register Commands
Read Status Register		05h(0000 0101B)	0		0		1+
Write Status Register		01h(0000 0001B)	0		0		1
Miscellaneous Commands
Read Manufacturer and Device ID		9Fh(1001 1111B)	0		0		1 to 4
Deep Power-down		B9h(1011 1001B)	0		0		0
Resume from Deep Power-down		ABh(1010 1011B)	0		0		0

Sector Protection Register Values

Value	Sector Protection Status
0	Sector is unprotected and can be programmed and erased.
1	Sector is protected and cannot be programmed or erased. This is the default state.

Read Sector Protection Register – Output Data

Value	Sector Protection Register Value
00h	Sector Protection Register value is 0 (sector is unprotected).
FFh	Sector Protection Register value is 1 (sector is protected).

OTP Security Register

Security Register Byte Number
0	1	…	62	63	64	65	…	126	127
One-Time User Programmable					Factory Programmed by Atmel

Write Status Register Format

Bit	7		6	5	4	3	2	1	0
	SPRL	X		Global Protect/Unprotect				X	X

Status Register Format

Bit	Name		Type	Description
7	SPRL	Sector Protection Registers Locked	R/W	0	Sector Protection Registers are unlocked (default).
				1	Sector Protection Registers are locked.
6	SPM	Sequential Program Mode Status	R	0	Byte/Page Programming Mode (default).
				1	Sequential Programming Mode entered.
5	EPE	Erase/Program Error	R	0	Erase or program operation was successful.
				1	Erase or program error detected.
4	WPP	Write Protect (WP) Pin Status	R	0	WP is asserted.
				1	WP is deasserted.
3:2	SWP	Software Protection Status	R	00	All sectors are software unprotected (all Sector Protection Registers are 0).
				01	Some sectors are software protected. Read individual Sector Protection Registers to determine which sectors are protected.
				10	Reserved for future use.
				11	All sectors are software protected (all Sector Protection Registers are 1 – default).
1	WEL	Write Enable Latch Status	R	0	Device is not write enabled (default).
				1	Device is write enabled.
0	RDY/BSY	Ready/Busy Status	R	0	Device is ready.
				1	Device is busy with an internal operation.

Notes:

1.     Only bit 7 of the Status Register will be modified when using the Write Status Register command.

2.     R/W = Readable and writable

R = Readable only

Manufacturer and Device ID Information

Byte No.	Data Type	Value
1	Manufacturer ID	1Fh
2	Device ID (Part 1)	43h
3	Device ID (Part 2)	00h
4	Extended Device Information String Length	00h

Manufacturer and Device ID Details

Data Type	7	6	5	4	3	2	1	0	Hex Value	Details
Manufacturer ID	JEDEC Assigned Code								1Fh	JEDEC Code: 0001 1111 (1Fh for Atmel)
	0	0	0	1	1	1	1	1
Device ID (Part 1)	Family Code			Density Code					43h	Family Code: 010 (AT25DF/26DFxxx series) Density Code: 00011 (2-Mbit)
	0	1	0	0	0	0	1	1
Device ID (Part 2)	Sub Code			Product Version Code					00h	Sub Code: 000 (Standard series) Product Version: 00000 (Initial version)
	0	0	0	0	0	0	0	0