6

3590A–FLASH–12/05

AT49BV163D(T)

At power-up or reset, all sectors are unlocked. To activate the lockdown for a specific sector, the

six-bus cycle Sector Lockdown command must be issued. Once a sector has been locked down,

the contents of the sector is read-only and cannot be erased or programmed.

4.7.1

Sector Lockdown Detection

A software method is available to determine if programming of a sector is locked down. When

the device is in the software product identification mode (see “Software Product Identification

Entry/Exit” sections on page 21), a read from address location 00002H within a sector will show

if programming the sector is locked down. If the data on I/O0 is low, the sector can be pro-

grammed; if the data on I/O0 is high, the program lockdown feature has been enabled and the

sector cannot be programmed. The software product identification exit code should be used to

return to standard operation.

4.7.2

Sector Lockdown Override

The only way to unlock a sector that is locked down is through reset or power-up cycles. After

power-up or reset, the content of a sector that is locked down can be erased and reprogrammed.

4.8

Erase Suspend/Erase Resume

The Erase Suspend command allows the system to interrupt a sector or chip erase operation

and then program or read data from a different sector within the memory. After the Erase Sus-

pend command is given, the device requires a maximum time of 15 µs to suspend the erase

operation. After the erase operation has been suspended, the system can then read data or pro-

gram data to any other sector within the device. An address is not required during the Erase

Suspend command. During a sector erase suspend, another sector cannot be erased. To

resume the sector erase operation, the system must write the Erase Resume command. The

Erase Resume command is a one-bus cycle command. The device also supports an erase sus-

pend during a complete chip erase. While the chip erase is suspended, the user can read from

any sector within the memory that is protected. The command sequence for a chip erase sus-

pend and a sector erase suspend are the same.

4.9

Program Suspend/Program Resume

The Program Suspend command allows the system to interrupt a programming operation and

then read data from a different byte/word within the memory. After the Program Suspend com-

mand is given, the device requires a maximum of 10 µs to suspend the programming operation.

After the programming operation has been suspended, the system can then read data from any

other byte/word that is not contained in the sector in which the programming operation was sus-

pended. An address is not required during the program suspend operation. To resume the

programming operation, the system must write the Program Resume command. The program

suspend and resume are one-bus cycle commands. The command sequence for the erase sus-

pend and program suspend are the same, and the command sequence for the erase resume

and program resume are the same.

4.10

Product Identification

The product identification mode identifies the device and manufacturer as Atmel. It is accessed

using a software operation.

For details, see “Operating Modes” on page 15 or “Software Product Identification Entry/Exit”

sections on page 21.