AT45DB642D-CNU SL954 Atmel, AT45DB642D-CNU SL954 Datasheet - Page 19

• Manufacturer Part Number: AT45DB642D-CNU SL954
• Manufacturer: Atmel

Specifications of AT45DB642D-CNU SL954

• Density: 64Mb
• Access Time (max): 6ns
• Interface Type: Parallel/Serial-SPI
• Address Bus: 1/8Bit
• Operating Supply Voltage (typ): 3.3V
• Operating Temp Range: -40C to 85C
• Package Type: CASON
• Program/erase Volt (typ): 2.7 to 3.6V
• Sync/async: Synchronous
• Operating Temperature Classification: Industrial
• Operating Supply Voltage (min): 2.7V
• Operating Supply Voltage (max): 3.6V
• Word Size: 8b
• Number Of Words: 8M
• Supply Current: 15mA
• Mounting: Surface Mount
• Pin Count: 8
• Lead Free Status / Rohs Status: Compliant

10.1.1
10.1.2
Figure 10-2. Read Sector Lockdown Register
3542K–DFLASH–04/09
SO or IO
SI or IO
Sector Lockdown Register
Reading the Sector Lockdown Register
7
7
- IO
- IO
CS
0
0
Each transition
represents 8 bits
Sector Lockdown Register is a nonvolatile register that contains 32 bytes of data, as shown
below:
Table 10-1.
The Sector Lockdown Register can be read to determine which sectors in the memory array are
permanently locked down. To read the Sector Lockdown Register, the CS pin must first be
asserted. Once the CS pin has been asserted, an opcode of 35H and a series of dummy bytes
(3 dummy bytes if using the serial interface or 7 dummy bytes if using the 8-bit interface) must
be clocked into the device via the SI or I/O7-O0 pins. After the last bit of the opcode and dummy
bytes have been clocked in, the data for the contents of the Sector Lockdown Register will be
clocked out on the SO pin or the I/O7-O0 pins. The first byte corresponds to sector 0 (0a, 0b) the
second byte corresponds to sector 1 and the las byte (byte 32) corresponds to sector 31. After
the last byte of the Sector Lockdown Register has been read, additional pulses on the SCK pin
will simply result in undefined data being output on the SO pin.
Deasserting the CS pin will terminate the Read Sector Lockdown Register operation and put the
SO pin or I/O7-O0 pins into a high-impedance state.
Table 10-2
Table 10-2.
Sector Number
Locked
Unlocked
Sectors 0a, 0b Unlocked
Sector 0a Locked
Sector 0b Locked (Page 8-255)
Sectors 0a, 0b Locked (Page 0-255)
Command
Read Sector Lockdown Register
Note:
Opcode
xx = Dummy Byte
details the values read from the Sector Lockdown Register.
Sector 0 (0a, 0b)
Sector Lockdown Register
X
Serial Interface = 3 Dummy Bytes
X
X
(Page 0-7)
Bit 7, 6
0a
00
00
11
11
Byte 1
Data Byte
35H
See Below
0 (0a, 0b)
n
(Page 8-255)
Bit 5, 4
0b
00
00
11
11
Data Byte
Byte 2
n + 1
xxH
8-bit Interface = 7 Dummy Bytes
Bit 3, 2
00
00
00
00
Byte 3
xxH
Bit 1, 0
Data Byte
1 to 31
00
00
00
00
n + 31
FFH
00H
Byte 4
xxH
Value
Data
C0H
00H
30H
F0H
19