AT45DB161E-SSHF-T Adesto Technologies, AT45DB161E-SSHF-T Datasheet - Page 23

• Manufacturer Part Number: AT45DB161E-SSHF-T
• Description: Flash 16M 2.3-3.6V 85Mhz Serial Flash
• Manufacturer: Adesto Technologies

Specifications of AT45DB161E-SSHF-T

• Data Bus Width: 8 bit
• Memory Type: Data Flash
• Memory Size: 16 Mbit
• Architecture: Flexible, Uniform Erase
• Timing Type: Synchronous
• Interface Type: SPI
• Supply Voltage - Max: 3.6 V
• Supply Voltage - Min: 2.3 V
• Maximum Operating Current: 26 mA
• Operating Temperature: - 40 C to + 85 C
• Mounting Style: SMD/SMT
• Package / Case: SOIC-8

8.
8.1
8.1.1
Security Features
Sector Lockdown
The device incorporates a sector lockdown mechanism that allows each individual sector to be permanently locked so
that it becomes read-only (ROM). This is useful for applications that require the ability to permanently protect a number of
sectors against malicious attempts at altering program code or security information.
Warning:
To issue the sector lockdown command, a 4-byte command sequence of 3Dh, 2Ah, 7Fh, and 30h must be clocked into
the device followed by three address bytes specifying any address within the sector to be locked down. After the last
address bit has been clocked in, the CS pin must be deasserted to initiate the internally self-timed lockdown sequence.
The lockdown sequence should take place in a maximum time of t
Register will indicate that the device is busy. If the device is powered-down before the completion of the lockdown
sequence, then the lockdown status of the sector cannot be guaranteed. In this case, it is recommended that the user
read the Sector Lockdown Register to determine the status of the appropriate sector lockdown bits or bytes and re-issue
the Sector Lockdown command if necessary.
Table 8-1.
Figure 8-1. Sector Lockdown
Read Sector Lockdown Register
The nonvolatile Sector Lockdown Register specifies which sectors in the main memory are currently unlocked or have
been permanently locked down. The Sector Lockdown Register is a read-only register and contains 16 bytes of data
which correspond to Sectors 0 through 15. To read the Sector Lockdown Register, an opcode of 35h must be clocked
into the device followed by three dummy bytes. 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. The first byte (byte
location 0) corresponds to Sector 0 (0a and 0b), the second byte corresponds to Sector 1, and the last byte (byte location
15) corresponds to Sector 15. After the last byte of the Sector Lockdown Register has been read, additional pulses on
the SCK pin will 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 into a
high-impedance state.
Command
Sector Lockdown
CS
SI
Each transition represents eight bits
Once a sector is locked down, it can never be erased or programmed, and it can never be unlocked.
Sector Lockdown Command
3Dh
Table 8-2
2Ah
details the format the Sector Lockdown Register.
7Fh
30h
Byte 1
3Dh
Address
P
byte
. During this time, the RDY/BUSY bit in the Status
Adesto AT45DB161E [DATASHEET]
Byte 2
2Ah
Address
byte
Address
byte
Byte 3
7Fh
8782D–DFLASH–11/2012
Byte 4
30h
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