Reading A Block's Lock Status; Locked State; Unlocked State - Analog Devices ADSP-BF506F Hardware Reference Manual

Reading a Block's Lock Status

The lock status of every block can be read in the read electronic signature
mode of the device. To enter this mode write 0x90 to the device. Subse-
quent reads at the address specified in
protection status of that block. The lock status is represented by
. indicates the block lock/unlock status and is set by the lock com-
D1 D0
mand and cleared by the unlock command. It is also automatically set
when entering lock-down.
the lock-down command. It cannot be cleared by software, only by a hard-
ware reset or power-down.
The following sections explain the operation of the locking system.

Locked State

The default status of all blocks on power-up or after a hardware reset is
locked (states (0,0,1) or (1,0,1)). Locked blocks are fully protected from
any program or erase. Any program or erase operations attempted on a
locked block returns an error in the status register. The status of a locked
block can be changed to unlocked or lock-down using the appropriate
software commands. An unlocked block can be locked by issuing the lock
command.

Unlocked State

Unlocked blocks (states (0,0,0), (1,0,0) (1,1,0)), can be programmed or
erased. All unlocked blocks return to the locked state after a hardware
reset or when the device is powered-down. The status of an unlocked
block can be changed to locked or locked-down using the appropriate
software commands. A locked block can be unlocked by issuing the
unlock command.
ADSP-BF50x Blackfin Processor Hardware Reference
Table 6-6 on page 6-17
indicates the lock-down status and is set by
D1
Internal Flash Memory
output the
D0
and
6-39