AT25DF641-S3H-T Atmel, AT25DF641-S3H-T Datasheet - Page 33

• 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

9.5.
3680F–DFLASH–4/10
If the device is powered-down during the OTP Security Register program cycle, then the contents of the 64-byte
user programmable portion of the OTP Security Register cannot be guaranteed and cannot be programmed
again.
The Program OTP Security Register command utilizes the internal 256-buffer for processing. Therefore, the
contents of the buffer will be altered from its previous state when this command is issued.
Figure 9-4.
Read OTP Security Register
The OTP Security Register can be sequentially read in a similar fashion to the Read Array operation up to the
maximum clock frequency specified by f
and the opcode of 77h must be clocked into the device. After the opcode has been clocked in, the three address
bytes must be clocked in to specify the starting address location of the first byte to read within the OTP Security
Register. Following the three address bytes, two dummy bytes must be clocked into the device before data can
be output.
After the three address bytes and the dummy bytes have been clocked in, additional clock cycles will result in
OTP Security Register data being output on the SO pin. When the last byte (00007Fh) of the OTP Security
Register has been read, the device will continue reading back at the beginning of the register (000000h). No
delays will be incurred when wrapping around from the end of the register to the beginning of the register.
Deasserting the
pin can be deasserted at any time and does not require that a full byte of data be read.
Figure 9-5.
SCK
SCK
SO
SO
CS
CS
SI
SI
Program OTP Security Register
Read OTP Security Register
CS
M S B
H IG H -IMP E DANC E
0
MS B
HIG H-IMP E DANC E
0
1
pin will terminate the read operation and put the SO pin into a high-impedance state. The
0
1
1
0
1
1
2
O P C O DE
0
2
1
OP C ODE
3
1
0
3
4
1
1
4
5
1
0
6
5
1
1
7
6
M S B
A
1
8
7
A
MS B
MAX
9
A
ADDR E S S B IT S A23-A0
ADDR E S S B IT S A23-A0
8
A
10 11
. To read the OTP Security Register, the
A
9
A
A
A
12
A
A
29 30
A
A
29 30
A
A
31 32
MS B
A
31 32
D
M S B
X
D
33
DAT A IN B Y T E 1
X
33
D
34
X
34
D
35
X
DO N'T C AR E
35
D
36
X
36
D
37 38
X
D
D
39
X
Atmel AT25DF641
X
X
CS
MS B
M S B
D
D
D
D
pin must first be asserted
DAT A IN B Y T E n
DAT A B Y T E 1
D
D
D
D
D
D
D
D
D
D
D
D
M S B
D
D
CS
33