
Intel
82802AB/AC Firmware Hub
R
Datasheet
25
4.9.1.
T_BLOCK_LK and T_MINUSxx_LK — Block-Locking Registers
Memory Address:
FFBx0002h (x = F-0h)
Default Value:
01h
Access:
R/W
Size:
8 bits (each)
Bit
Function
7:3
Reserved
2
Read-Lock
1 = Prevents read operations in the block where set.
0 = Normal operation for reads in the block where clear. This is the default state.
1
Lock-Down
1 = Prevents further set or clear operations to the Write Lock and Read Lock bits. Lock-Down only can
be set, but not cleared. The block will remain locked-down until reset (with RST# or INIT#), or until
the device is power-cycled.
0 = Normal operation for Write Lock and Read Lock bit altering in the block where clear. This is the
default state.
0
Write-Lock
1 = Prevents program or erase operations in the block where set. This is the default state.
0 = Normal operation for programming and erase in the block where clear.
Table 6.
Register-Based Locking Value Definitions
Data
Reserved
Data 7:3
Read Lock,
Data 2
Lock-Down,
Data 1
Write Lock,
Data 0
Resulting block state
(1)
.
00h
00000
0
0
0
Full access
01h
00000
0
0
1
Write locked.
Default state at power-
up
02h
00000
0
1
0
Locked open (full access locked down).
03h
00000
0
1
1
Write-locked down.
04h
00000
1
0
0
Read locked.
05h
00000
1
0
1
Read and write locked.
06h
00000
1
1
0
Read-locked down.
07h
00000
1
1
1
Read- and write-locked down.
Note:
The write-lock bit must be set to the desired protection state prior to starting a program or erase
operation, since it is sampled at the beginning of the operation. Changing the state of the write-lock bit
during a program or erase operation may cause unpredictable results. If the state of the write-lock bit
changes during a program suspend or erase suspend state, changes in the block’s locking status do not
occur immediately. The suspended operation may be resumed successfully. The new lock status will take
place after the program or erase operation completes. The individual bit functions are described in the
following sections.