MBM29F080A-55 FUJITSU [Fujitsu Component Limited.], MBM29F080A-55 Datasheet - Page 13

• Manufacturer Part Number: MBM29F080A-55
• Description: 8M (1M X 8) BIT
• Manufacturer: FUJITSU [Fujitsu Component Limited.]

Temporary Sector Group Unprotection
Notes: 1. Address bits A
*: Either of the two reset commands will reset the device.
Command Definitions
Read/Reset*
Reset/Read*
Manufacture Code
Device Code
Byte Program
Chip Erase
Sector Erase
Sector Erase Suspend
Sector Erase Resume
This feature allows temporary unprotection of previously protected sector groups of the MBM29F080A device
in order to change data. The Sector Group Unprotection mode is activated by setting the RESET pin to high
voltage (12 V). During this mode, formerly protected sector groups can be programmed or erased by selecting
the sector group addresses. Once the 12 V is taken away from the RESET pin, all the previously protected sector
groups will be protected again. Refer to Figures 14 and 21.
Device operations are selected by writing specific address and data sequences into the command register.
Writing incorrect address and data values or writing them in the improper sequence will reset the device to the
read mode. Table 6 defines the valid register command sequences. Note that the Erase Suspend (B0H) and
Erase Resume (30H) commands are valid only while the Sector Erase operation is in progress. Moreover, both
Read/Reset commands are functionally equivalent, resetting the device to the read mode.
Command
Sequence
2. Bus operations are defined in Table 2.
3. RA = Address of the memory location to be read.
4. RD = Data read from location RA during read operation.
5. Read and Byte program functions to non-erasing sectors are allowed in the Erase Suspend mode.
6. The system should generate the following address pattens: 555H or 2AAH to addresses A
Sector Address (SA).
PA = Address of the memory location to be programmed. Addresses are latched on the falling edge of
SA = Address of the sector to be erased. The combination of A
PD = Data to be programmed at location PA. Data is latched on the rising edge of WE.
the WE pulse.
any sector.
Cycles
Req'd
Write
Bus
1
3
3
3
4
6
6
11
to A
Erase can be suspended during sector erase with Addr (“H” or “L”), Data (B0H)
Erase can be resumed after suspend with Addr (“H” or “L”), Data (30H)
XXXH F0H
Write Cycle
Addr. Data Addr. Data Addr. Data Addr. Data Addr. Dat
555H AAH 2AAH 55H
555H AAH 2AAH 55H
555H AAH 2AAH 55H
555H AAH 2AAH 55H
555H AAH 2AAH 55H
555H AAH 2AAH 55H
First Bus
19
Table 6
= X = “H” or “L” for all address commands except or Program Address (PA) and
MBM29F080A Command Definitions
Second Bus
Write Cycle
—
—
Write Cycle
555H
555H
555H
555H A0H
555H
555H
Third Bus
—
F0H
90H
90H
80H
80H
—
MBM29F080A
Fourth Bus
Read/Write
555H AAH 2AAH 55H 555H
555H AAH 2AAH 55H
00H
01H
19
RA
PA
—
, A
Cycle
18
, A
04H
05H
RD
PD
—
17
, and A
Fifth Bus
—
—
—
—
—
Cycle
Write
16
will uniquely select
—
—
—
—
—
a
-55/-70/-90
0
Write Cycle
Addr. Data
Sixth Bus
to A
SA
—
—
—
—
—
10
.
10H
30H
—
—
—
—
—
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