M29W640GB NUMONYX [Numonyx B.V], M29W640GB Datasheet - Page 15

• Manufacturer Part Number: M29W640GB
• Description: 64 Mbit (8Mb x8 or 4Mb x16, Page) 3V supply Flash memory
• Manufacturer: NUMONYX [Numonyx B.V]

M29W640GH, M29W640GL, M29W640GT, M29W640GB
2.7
2.8
Table 6.
V
PP
V
/WP
IL
Write Enable (W)
The Write Enable, W, controls the Bus Write operation of the memory’s Command Interface.
V
The V
use an external high voltage power supply to reduce the time required for Unlock Bypass
Program operations. The Write Protect performs hardware protection:
●
●
The V
characteristics).
When V
four outermost blocks (M29W640GT and M29W640GB) are protected. Program and Erase
operations in this block are ignored while V
When V
of the outermost blocks. Program and Erase operations can now modify the data in the
outermost blocks unless the block is protected using Block Protection.
Applying 12V to the V
(including the outermost blocks) using a High Voltage Block Protection technique (In-
System or Programmer technique). See
When V
Bypass mode. When V
During Unlock Bypass Program operations the memory draws I
programming circuits. See the description of the Unlock Bypass command in the Command
Interface section. The transitions from V
t
Never raise V
memory may be left in an indeterminate state.
A 0.1µF capacitor should be connected between the V
Ground pin to decouple the current surges from the power supply. The PCB track widths
must be sufficient to carry the currents required during Unlock Bypass Program, I
Hardware Protection
VHVPP
PP
V
V
It protects the first and last block on M29W640GH and M29W640GL devices.
It protects the first two and the last two boot blocks on M29W640GT and M29W640GB
devices.
/Write Protect (V
IH
ID
PP
PP
, see
PP
PP
PP
/Write Protect pin provides two functions. The V
/Write Protect pin may be left floating or unconnected (see
/Write Protect is Low, V
/Write Protect is High, V
/Write Protect is raised to V
Figure 18: Accelerated Program Timing
PP
/Write Protect to V
RP
M29W640GH and
M29W640GH and
M29W640GT and
M29W640GT and
M29W640GB
M29W640GB
M29W640GL
M29W640GL
PP
PP
/WP pin will temporarily unprotect any block previously protected
/Write Protect returns to V
PP
/WP)
IL
PP
IH
, the two outermost (M29W640GH and M29W640GL) or
, the memory reverts to the previous protection status
from any mode except Read mode, otherwise the
4 outermost parameter blocks protected from
Program/Erase operations
2 outermost blocks protected from Program/Erase
operations
All blocks temporarily unprotected except the 4 outermost
blocks
All blocks temporarily unprotected except the 2 outermost
blocks
PP
IH
Table 6: Hardware Protection
the memory automatically enters the Unlock
to V
PP
/Write Protect is Low, even when RP is at V
PP
and from V
IH
waveforms.
or V
PP
PP
/Write Protect pin and the V
IL
function allows the memory to
normal operation resumes.
Function
PP
PP
to V
from the pin to supply the
Table 17: DC
IH
must be slower than
for details.
Signal descriptions
PP
.
SS
15/90
ID
.