MBM29PL12LM
10
32
Extended Sector Group Protection
In addition to normal sector group protection, the device has Extended Sector Group Protection as extended
function. This function enables protection of the sector group by forcing V
ID
on RESET pin and writes a command
sequence. Unlike conventional procedures, it is not necessary to force V
ID
and control timing for control pins.
The only RESET pin requires V
ID
for sector group protection in this mode. The extended sector group protection
requires V
ID
on RESET pin. With this condition, the operation is initiated by writing the set-up command (60h)
into the command register. Then the sector group addresses pins (A
22
, A
21
, A
20
, A
19
, A
18
, A
17,
A
16
and A
15
) and
(A
6
, A
3
, A
2
, A
1
, A
0
) = (0, 0, 0, 1, 0) should be set to the sector group to be protected (set V
IL
for the other addresses
pins is recommended), and write extended sector group protection command (60h). A sector group is typically
protected in 250
μ
s. To verify programming of the protection circuitry, the sector group addresses pins (A
6
, A
3
,
A
2
, A
1
, A
0
) = (0, 0, 0, 1, 0) should be set and write a command (40h). Following the command write, a logical “1”
at device output DQ
0
will produce for protected sector in the read operation. If the output data is logical “0”, write
the extended sector group protection command (60h) again. To terminate the operation, set RESET pin to V
IH
.
(Refer to the “Extended Sector Group Protection Timing Diagram” in
■
TIMING DIAGRAM and “Extended Sector
Group Protection Algorithm” in
■
FLOW CHART.)
Query Command (CFI : Common Flash Memory Interface)
The CFI (Common Flash Memory Interface) specification outlines device and host system software interrogation
handshake which allows specific vendor-specified software algorithms to be used for entire families of devices.
This allows device-independent, JEDEC ID-independent, and forward-and backward-compatible software sup-
port for the specified flash device families. Refer to CFI specification in detail.
The operation is initiated by writing the query command (98h) into the command register. Following the command
write, a read cycle from specific address retrieves device information. Please note that output data of upper byte
(DQ
15
to DQ
8
) is “0”. Refer to the CFI code table. To terminate operation, it is necessary to write the Reset
command sequence into the register. (See “Common Flash Memory Interface Code” in
■
DEVICE BUS OPER-
ATION.)