RC28F320C3TD90 Micron Technology Inc, RC28F320C3TD90 Datasheet - Page 48

• Manufacturer Part Number: RC28F320C3TD90
• Manufacturer: Micron Technology Inc

Specifications of RC28F320C3TD90

• Lead Free Status / Rohs Status: Not Compliant

11.0
11.1
Figure 14: Block Locking State Diagram
11.1.1
Datasheet
48
Power-Up/Reset
Security Modes
Flexible Block Locking
The C3 Discrete device offers an instant, individual block-locking scheme that allows
any block to be locked or unlocked with no latency, enabling instant code and data
protection.
This locking scheme offers two levels of protection. The first level allows software-only
control of block locking (useful for data blocks that change frequently), while the
second level requires hardware interaction before locking can be changed (useful for
code blocks that change infrequently).
The following sections will discuss the operation of the locking system. The term “state
[abc]” will be used to specify locking states; for example, “state [001],” where
a = value of WP#, b = bit D1 of the Block Lock Status Register, and c = bit D0 of the
Block Lock Status Register.
displays all of the possible locking states.
Locking Operation
The locking status of each block can be set to Locked, Unlocked, or Lock-Down, each of
which will be described in the following sections. See
Diagram” on page 48
Notes:
1. [a,b,c] represents [WP#, D1, D0]. X = Don’t Care.
2. D1 indicates block Lock-down status. D1 = ‘0’, Lock-down has not been issued to
3. D0 indicates block lock status. D0 = ‘0’, block is unlocked. D0 = ‘1’, block is locked.
4. Locked-down = Hardware + Software locked.
5. [011] states should be tracked by system software to determine difference
this block. D1 = ‘1’, Lock-down has been issued to this block.
between Hardware Locked and Locked-Down states.
Unlocked
Locked
[X00]
[X01]
and
Figure 21, “Locking Operations Flowchart” on page
Figure 14, “Block Locking State Diagram” on page 48
Software Block Lock (0x60/0x01) or Software Block Unlock (0x60/0xD0)
Software Block Lock-Down (0x60/0x2F)
WP# hardware control
Software
Locked-
Down
Locked
[111]
[011]
4,5
WP# Hardware Control
Figure 14, “Block Locking State
Hardware
Unlocked
Locked
[011]
[110]
5
C3 Discrete
60.
March 2008
290645-24