AT25DF641-MWH-Y Atmel, AT25DF641-MWH-Y Datasheet - Page 26

• Manufacturer Part Number: AT25DF641-MWH-Y
• Description: IC FLASH 64MBIT 100MHZ 8VDFN
• Manufacturer: Atmel

Specifications of AT25DF641-MWH-Y

• Format - Memory: FLASH
• Memory Type: DataFLASH
• Memory Size: 64M (32K pages x 256 bytes)
• Speed: 100MHz
• Interface: SPI, 3-Wire Serial
• Voltage - Supply: 2.7 V ~ 3.6 V
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 8-VDFN
• Architecture: Sectored
• Interface Type: SPI Serial
• Supply Voltage (max): 3.6 V
• Supply Voltage (min): 2.7 V
• Maximum Operating Current: 19 mA
• Mounting Style: SMD/SMT
• Organization: 64 KB x 128
• Cell Type: NOR
• Density: 64Mb
• Access Time (max): 5ns
• Boot Type: Not Required
• Address Bus: 1b
• Operating Supply Voltage (typ): 3.3V
• Operating Temp Range: -40C to 85C
• Package Type: VDFN
• Sync/async: Synchronous
• Operating Temperature Classification: Industrial
• Operating Supply Voltage (min): 2.7V
• Operating Supply Voltage (max): 3.6V
• Supply Current: 19mA
• Mounting: Surface Mount
• Pin Count: 8
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

8.6.
26
If the desire is to only change the SPRL bit without performing a Global Protect or Global Unprotect, then the
system can simply write a 0Fh to the first byte of the Status Register to change the SPRL bit from a logical “1” to a
logical “0” provided the
a logical “0” to a logical “1” without affecting the current sector protection status (no changes will be made to the
Sector Protection Registers).
When writing to the first byte of the Status Register, bits five, four, three, and two will not actually be modified but
will be decoded by the device for the purposes of the Global Protect and Global Unprotect functions. Only bit
seven, the SPRL bit, will actually be modified. Therefore, when reading the first byte of the Status Register, bits
five, four, three, and two will not reflect the values written to them but will instead indicate the status of the
and the sector protection status. Please refer to “Status Register Commands” on page 34 and Table 10-1 on page
34 for details on the Status Register format and what values can be read for bits five, four, three, and two.
Read Sector Protection Registers
The Sector Protection Registers can be read to determine the current software protection status of each sector.
Reading the Sector Protection Registers, however, will not determine the status of the
To read the Sector Protection Register for a particular sector, the
3Ch must be clocked in. Once the opcode has been clocked in, three address bytes designating any address
within the sector must be clocked in. After the last address byte has been clocked in, the device will begin
outputting data on the SO pin during every subsequent clock cycle. The data being output will be a repeating byte
of either FFh or 00h to denote the value of the appropriate Sector Protection Register.
At clock frequencies above f
frequencies above f
correct status of the appropriate Sector Protection Register.
Table 8-3.
Deasserting the
pin can be deasserted at any time and does not require that a full byte of data be read.
In addition to reading the individual Sector Protection Registers, the Software Protection Status (SWP) bits in the
Status Register can be read to determine if all, some, or none of the sectors are software protected (refer to
“Read Status Register” on page 34 for more details).
Atmel AT25DF641
Output Data
FFh
00h
Read Sector Protection Register - Output Data
Sector Protection Register Value
Sector Protection Register value is 0 (sector is unprotected)
Sector Protection Register value is 1 (sector is protected)
CS
CLK
pin will terminate the read operation and put the SO pin into a high-impedance state. The
, at least two bytes of data must be clocked out from the device in order to determine the
WP
pin is deasserted. Likewise, the system can write an F0h to change the SPRL bit from
CLK
, the first byte of data output will not be valid. Therefore, if operating at clock
CS
pin must first be asserted and the opcode of
WP
pin.
3680F–DFLASH–4/10
WP
pin
CS