AT25DF021-MH-T Atmel, AT25DF021-MH-T Datasheet - Page 26

• Manufacturer Part Number: AT25DF021-MH-T
• Description: IC FLASH 2MBIT 70MHZ 8UDFN
• Manufacturer: Atmel

Specifications of AT25DF021-MH-T

• Format - Memory: FLASH
• Memory Type: DataFLASH
• Memory Size: 2M (256K x 8)
• Speed: 70MHz
• Interface: SPI, 3-Wire Serial
• Voltage - Supply: 2.7 V ~ 3.6 V
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 8-UDFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

12. Other Commands and Functions
12.1
Table 12-1.
Table 12-2.
26
Data Type
Manufacturer ID
Device ID (Part 1)
Device ID (Part 2)
Byte No.
Read Manufacturer and Device ID
AT25DF021
1
2
3
4
Manufacturer and Device ID Information
Manufacturer and Device ID Details
Bit 7
0
0
0
Family Code
Sub Code
Data Type
Manufacturer ID
Device ID (Part 1)
Device ID (Part 2)
Extended Device Information String Length
Bit 6
Identification information can be read from the device to enable systems to electronically query
and identify the device while it is in system. The identification method and the command opcode
comply with the JEDEC standard for “Manufacturer and Device ID Read Methodology for SPI
Compatible Serial Interface Memory Devices”. The type of information that can be read from the
device includes the JEDEC defined Manufacturer ID, the vendor specific Device ID, and the ven-
dor specific Extended Device Information.
Since not all Flash devices are capable of operating at very high clock frequencies, applications
should be designed to read the identification information from the devices at a reasonably low
clock frequency to ensure that all devices to be used in the application can be identified properly.
Once the identification process is complete, the application can then increase the clock fre-
quency to accommodate specific Flash devices that are capable of operating at the higher clock
frequencies.
To read the identification information, the CS pin must first be asserted and the opcode of 9Fh
must be clocked into the device. After the opcode has been clocked in, the device will begin out-
putting the identification data on the SO pin during the subsequent clock cycles. The first byte
that will be output will be the Manufacturer ID followed by two bytes of Device ID information.
The fourth byte output will be the Extended Device Information String Length, which will be 00h
indicating that no Extended Device Information follows. After the Extended Device Information
String Length byte is output, the SO pin will go into a high-impedance state; therefore, additional
clock cycles will have no affect on the SO pin and no data will be output. As indicated in the
JEDEC standard, reading the Extended Device Information String Length and any subsequent
data is optional.
Deasserting the CS pin will terminate the Manufacturer and Device ID read 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 be read.
0
1
0
Bit 5
0
0
0
JEDEC Assigned Code
Bit 4
1
0
0
Bit 3
Product Version Code
1
0
0
Density Code
Bit 2
1
0
0
Bit 1
1
1
0
Bit 0
1
1
0
Value
Hex
1Fh
43h
00h
Details
JEDEC Code:
Family Code:
Density Code:
Sub Code:
Product Version: 00000 (Initial version)
0001 1111 (1Fh for Atmel)
010 (AT25DF/26DFxxx series)
00011 (2-Mbit)
000 (Standard series)
3677D–DFLASH–04/09
Value
1Fh
00h
43h
00h