M29DW323DT70N6E STMicroelectronics, M29DW323DT70N6E Datasheet - Page 43

• Manufacturer Part Number: M29DW323DT70N6E
• Description: IC, FLASH, 32MBIT, 70NS, TSOP-48
• Manufacturer: STMicroelectronics

Specifications of M29DW323DT70N6E

• Memory Type: Flash - Boot Block
• Memory Size: 32Mbit
• Memory Configuration: 4M X 8 / 2M X 16
• Ic Interface Type: Parallel
• Access Time: 70ns
• Supply Voltage Range: 2.7V To 3.6V
• Memory Case Style: TSOP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

APPENDIX D. BLOCK PROTECTION
Block protection can be used to prevent any oper-
ation from modifying the data stored in the memo-
ry. The blocks are protected in groups, refer to
Appendix A, Tables 21 and 22 for details of the
Protection Groups. Once protected, Program and
Erase operations within the protected group fail to
change the data.
There are three techniques that can be used to
control Block Protection, these are the Program-
mer technique, the In-System technique and Tem-
porary Unprotection. Temporary Unprotection is
controlled by the Reset/Block Temporary Unpro-
tection pin, RP; this is described in the Signal De-
scriptions section.
Programmer Technique
The Programmer technique uses high (V
age levels on some of the bus pins. These cannot
be achieved using a standard microprocessor bus,
therefore the technique is recommended only for
use in Programming Equipment.
To protect a group of blocks follow the flowchart in
Figure 20, Programmer Equipment Block Protect
Flowchart. To unprotect the whole chip it is neces-
sary to protect all of the groups first, then all
groups can be unprotected at the same time. To
unprotect the chip follow Figure 21, Programmer
Equipment Chip Unprotect Flowchart. Table 30,
Programmer Technique Bus Operations, gives a
summary of each operation.
Table 30. Programmer Technique Bus Operations, BYTE = V
Note: 1. Block Protection Groups are shown in Appendix A, Tables 21 and 22.
Block (Group)
Protect
Chip Unprotect
Block (Group)
Protection Verify
Block (Group)
Unprotection Verify
Operation
(1)
V
V
V
V
E
ID
IL
IL
IL
V
V
V
V
G
ID
ID
IL
IL
V
V
IL
IL
V
V
W
Pulse
Pulse
IH
IH
ID
A0 = V
A0 = V
) volt-
A9 = V
A9 = V
IL
IL
A12-A20 Block Address
A12-A20 Block Address
, A1 = V
, A1 = V
ID
ID
, A12-A20 Block Address
Address Inputs
, A12 = V
The timing on these flowcharts is critical. Care
should be taken to ensure that, where a pause is
specified, it is followed as closely as possible. Do
not abort the procedure before reaching the end.
Chip Unprotect can take several seconds and a
user message should be provided to show that the
operation is progressing.
In-System Technique
The In-System technique requires a high voltage
level on the Reset/Blocks Temporary Unprotect
pin, RP. This can be achieved without violating the
maximum ratings of the components on the micro-
processor bus, therefore this technique is suitable
for use after the memory has been fitted to the sys-
tem.
To protect a group of blocks follow the flowchart in
Figure 22, In-System Block Protect Flowchart. To
unprotect the whole chip it is necessary to protect
all of the groups first, then all the groups can be
unprotected at the same time. To unprotect the
chip follow Figure 23, In-System Chip Unprotect
Flowchart.
The timing on these flowcharts is critical. Care
should be taken to ensure that, where a pause is
specified, it is followed as closely as possible. Do
not allow the microprocessor to service interrupts
that will upset the timing and do not abort the pro-
cedure before reaching the end. Chip Unprotect
can take several seconds and a user message
should be provided to show that the operation is
progressing.
Others = X
Others = X
Others = X
Others = X
A0-A20
IH
IH
, A6 = V
, A6 = V
IH
, A15 = V
IH
IH
IL
or V
, A9 = V
, A9 = V
M29DW323DT, M29DW323DB
IL
IH
ID
ID
,
,
DQ15A–1, DQ14-DQ0
Data Inputs/Outputs
Retry = XX00h
Retry = XX01h
Pass = XX01h
Pass = XX00h
X
X
43/49