![](http://datasheet.mmic.net.cn/330000/MBM29F800TA_datasheet_16438893/MBM29F800TA_11.png)
11
MBM29F800TA
-55/-70/-90
/MBM29F800BA
-55/-70/-90
*1: A
-1
is for Byte mode.
*2: Outputs 01H at protected sector addresses and outputs 00H at unprotected sector addresses.
(B): Byte mode
(W): Word mode
Write
Device erasure and programming are accomplished via the command register. The contents of the register serve
as inputs to the internal state machine. The state machine outputs dictate the function of the device.
The command register itself does not occupy any addressable memory location. The register is a latch used to
store the commands, along with the address and data information needed to execute the command. The
command register is written by bringing WE to V
IL
, while CE is at V
IL
and OE is at V
IH
. Addresses are latched on
the falling edge of WE or CE, whichever happens later; while data is latched on the rising edge of WE or CE,
whichever happens first. Standard microprocessor write timings are used.
Refer to AC Write Characteristics and the Erase/Programming Waveforms for specific timing parameters.
Sector Protection
The MBM29F800TA/BA features hardware sector protection. This feature will disable both program and erase
operations in any number of sectors (0 through 18). The sector protection feature is enabled using programming
equipment at the user’s site. The device is shipped with all sectors unprotected.
Table 4 .1 MBM29F800TA/BA Sector Protection Verify Autoselect Codes
Type
A
12
to A
18
A
6
A
1
A
0
A
-1
*
1
Code
(HEX)
Manufacture’s Code
X
V
IL
V
IL
V
IL
V
IL
04H
Device Code
MBM29F800TA
Byte
X
V
IL
V
IL
V
IH
V
IL
D6H
Word
X
22D6H
MBM29F800BA
Byte
X
V
IL
V
IL
V
IH
V
IL
58H
Word
X
2258H
Sector Protection
Sector
Addresses
V
IL
V
IH
V
IL
V
IL
01H*
2
Table 4 .2 Expanded Autoselect Code Table
Type
Code
DQ
15
DQ
14
DQ
13
DQ
12
DQ
11
DQ
10
DQ
9
DQ
8
DQ
7
DQ
6
DQ
5
DQ
4
DQ
3
DQ
2
DQ
1
DQ
0
Manufacture’s Code
04H A
-1
/0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
Device
Code
MBM29F800TA
(B)
D6H A
-1
HI-Z HI-Z HI-Z HI-Z HI-Z HI-Z HI-Z 1
1
0
1
0
1
1
0
(W)
22D6H
0
0
1
0
0
0
1
0
1
1
0
1
0
1
1
0
MBM29F800BA
(B)
58H A
-1
HI-Z HI-Z HI-Z HI-Z HI-Z HI-Z HI-Z 0
1
0
1
1
0
0
0
(W)
2258H
0
0
1
0
0
0
1
0
0
1
0
1
1
0
0
0
Sector Protection
01H A
-1
/0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1