AT45DB642D-CNU-SL954 ATMEL [ATMEL Corporation], AT45DB642D-CNU-SL954 Datasheet - Page 21

• Manufacturer Part Number: AT45DB642D-CNU-SL954
• Description: 64-megabit 2.7-volt Dual-interface DataFlash
• Manufacturer: ATMEL [ATMEL Corporation]

Figure 10-3. Program Security Register
10.2.2
Figure 10-4. Read Security Register
3542H–DFLASH–4/08
SO or IO
SI or IO
SI or IO
Reading the Security Register
7
7
- IO
- IO
CS
7
- IO
CS
0
0
0
Each transition
represents 8 bits
Each transition
represents 8 bits
The Security Register can be read by first asserting the CS pin and then clocking in an opcode
of 77H followed by three dummy bytes if using the serial interface and seven dummy bytes if
using the 8-bit interface. After the last don't care bit has been clocked in, the content of the
Security Register can be clocked out on the SO or I/O7 - I/O0 pins. After the last byte of the
Security Register has been read, additional pulses on the SCK/CLK pin will simply result in
undefined data being output on the SO or I/O7 - I/O0 pins.
Deasserting the CS pin will terminate the Read Security Register operation and put the SO or
I/O7 - I/O0 pins into a high-impedance state.
Opcode
Opcode
Byte 1
Opcode
Byte 2
X
Opcode
Byte 3
X
Opcode
Byte 4
X
Data Byte
n
Data Byte
n
Data Byte
n + 1
Data Byte
n + 1
AT45DB642D
Data Byte
n + x
Data Byte
n + x
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