M29F080D55N6 Micron Technology Inc, M29F080D55N6 Datasheet - Page 31

• Manufacturer Part Number: M29F080D55N6
• Manufacturer: Micron Technology Inc

Specifications of M29F080D55N6

• Cell Type: NOR
• Density: 8Mb
• Access Time (max): 55ns
• Interface Type: Parallel
• Boot Type: Not Required
• Address Bus: 20b
• Operating Supply Voltage (typ): 5V
• Operating Temp Range: -40C to 85C
• Package Type: TSOP
• Program/erase Volt (typ): 4.5 to 5.5V
• Sync/async: Asynchronous
• Operating Temperature Classification: Industrial
• Operating Supply Voltage (min): 4.5V
• Operating Supply Voltage (max): 5.5V
• Word Size: 8b
• Number Of Words: 1M
• Supply Current: 20mA
• Mounting: Surface Mount
• Pin Count: 40
• Lead Free Status / Rohs Status: Not Compliant

APPENDIX C. 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, Table 15 for details of the Protection
Groups. Once protected, Program and Erase op-
erations 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.
To protect the Extended Block issue the Enter Ex-
tended Block command and then use either the
Programmer or In-System technique. Once pro-
tected issue the Exit Extended Block command to
return to read mode. The Extended Block protec-
tion is irreversible, once protected the protection
cannot be undone.
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 14, 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 15, Programmer
Equipment Chip Unprotect Flowchart. Table 22,
Table 22. Programmer Technique Bus Operations, BYTE = V
Note: 1. Block Protection Groups are shown in Appendix A, Table 15.
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-A19 Block Address
A12-A19 Block Address
, A1 = V
, A1 = V
ID
ID
, A12-A19 Block Address
Address Inputs
, A12 = V
Programmer Technique Bus Operations, gives a
summary of each operation.
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 16, 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 17, 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-A19
IH
IH
, A6 = V
, A6 = V
IH
, A15 = V
IH
IH
IL
or V
, A9 = V
, A9 = V
IL
IH
ID
ID
,
,
DQ15A–1, DQ14-DQ0
Data Inputs/Outputs
Retry = XX00h
Retry = XX01h
Pass = XX01h
Pass = XX00h
X
X
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