AT25DF641-S3H-T Atmel, AT25DF641-S3H-T Datasheet - Page 30

• Manufacturer Part Number: AT25DF641-S3H-T
• Description: IC FLASH 64MBIT 100MHZ 16SOIC
• Manufacturer: Atmel

Specifications of AT25DF641-S3H-T

• 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: 16-SOIC (0.300", 7.5mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

9.2.
30
Freeze Sector Lockdown State
The current sector lockdown state can be permanently frozen so that no further modifications to the Sector
Lockdown Registers can be made; therefore, the Sector Lockdown command will be permanently disabled, and
no additional sectors can be locked down aside from those already locked down. Any attempts to issue the Sector
Lockdown command after the sector lockdown state has been frozen will be ignored.
Before the Freeze Sector Lockdown State command can be issued, the Write Enable command must have been
previously issued to set the WEL bit in the Status Register to a logical “1”. In addition, the Sector Lockdown
Enabled (SLE) bit in the Status Register must have also been previously set to the logical “1” state. To issue the
Freeze Sector Lockdown State command, the
clocked into the device followed by three command specific address bytes of 55AA40h. After the three address
bytes have been clocked in, a confirmation byte of D0h must be clocked in immediately following the three
address bytes. Any additional data clocked into the device will be ignored. When the
current sector lockdown state will be permanently frozen within a time of t
Status Register will be reset back to the logical “0” state, and the SLE bit will be permanently reset to a logical “0”
to indicate that the Sector Lockdown command is permanently disabled.
The complete and correct three address bytes and the confirmation byte must be clocked into the device before
the
otherwise, the device will abort the operation. When the device aborts the Freeze Sector Lockdown State
operation, the WEL bit in the Status Register will be reset to a logical “0”; however, the state of the SLE bit will be
unchanged.
Figure 9-2.
Atmel AT25DF641
SCK
SO
CS
CS
SI
pin is deasserted, and the
Freeze Sector Lockdown State
HIG H-IMP E DANC E
MS B
0
0
0
1
1
2
OP C ODE
1
3
0
4
1
5
CS
0
6
pin must be deasserted on an even byte boundary (multiples of eight bits);
0
7
MS B
0
ADDR E S S B IT S A23-A0
8
1
9
0
CS
pin must first be asserted and the opcode of 34h must be
0
29 30
0
0
31 32
MS B
C ONF IR MAT ION B Y T E IN
1
1
33
0
34
1
35
0
36
0
37 38
0
LOCK
0
39
. In addition, the WEL bit in the
CS
pin is deasserted, the
3680F–DFLASH–4/10