MOSEL VITELIC
Boot Block Protection
The V29C51001T/V29C51001B features
hardware Boot Block Protection. The boot block
sector protection is enabled when high voltage
(12.5V) is applied to OE and A9 pins with CE pin
LOW and WE pin lOW. The sector protection is
desabled when high voltage is applied to OE, CE
and A9 pins with WE pin LOW. Other pins can be
HIGH or LOW. This is shown in table 1.
V29C51001T/V29C51001B
Device ID
In Autoselect mode, performing a read at
address XXX1H will determine whether the device
is a Top Boot Block device or a Bottom Boot Block
device. If the data is 01H, the device is a Top Boot
Block. If the data is A1H, the device is a Bottom
Boot Block device (see Table 3).
In addition, the device ID can also be read via the
command register when the device is erased or
programmed in a system without applying high
voltage to the A
9
pin. When A
0
is HIGH, the device
ID is presented at the outputs.
Autoselect
The V29C51001T/V29C51001B features an
Autoselect mode to identify
the Boot Block
(protected/unprotected), the Device (Top/Bottom),
and the manufacturer ID.
To get to the Autoselect mode, a high voltage
(V
H
) must be applied to the A
9
pin. Once the A
9
signal is returned to LOW or HIGH, the device will
return to the previous mode.
Manufacturer ID
In Autoselect mode, performing a read at
address. XXXX0H will determine the manufacturer
ID. 40H is the manufacturer code for Mosel Vitelic
Flash.
In addition the manufacturer ID can also be read
via the command register when the device is
erased or programmed in a system without
applying high voltage to the A
9
pin. when A
0
is
LOW, the manufacturer ID is presented at the
outputs.
Boot Block Protection Status
In Autoselect mode, performing a read at
address XXX2H will indicate if the Top Boot Block
sector or the Bottom Boot Block sector is locked
out. If the data is 01H, the Top/Bottom Boot Block is
protected. If the data is 00H, the Top/Bottom Boot
Block is unprotected. (see Table 3.)
Hardware Data Protection
V
CC
Sense Protection:
the program operation is
inhibited when VCC is less than 2.5V.
Noise Protection:
a CE or WE pulse of less than
5ns will not initiate a program cycle.
Program Inhibit Protection:
holding any one of
OE LOW, CE HIGH or WE HIGH inhibits a program
cycle.
Table 3. Autoselect Decoding
Address
Decoding Mode
Boot Block Protection
Boot Block
Top
Bottom
A
0
V
IL
V
IL
V
IH
A
1
V
IH
V
IH
V
IL
A
2
–A
13
X
X
X
A
14
–A
16
X
X
X
Data I/O
0
–I/O
7
01H: protected
00H: unprotected
01H
A1H
Device ID
Top
Bottom
Manufacture ID
NOTE:
1. X = Don’t Care, V
IH
= HIGH, V
IL
= LOW.
V
IL
V
IL
X
X
40H
V29C51001T/V29C51001B Rev. 0.8 October 2000
11
MOSEL [ MOSEL VITELIC, CORP ]
