M29W128GH60ZS3F View Datasheet(PDF) - Numonyx -> Micron
Part Name
Description
MFG CO.
M29W128GH60ZS3F
Numonyx -> Micron
'M29W128GH60ZS3F' PDF : 94 Pages View PDF
Signal descriptions
M29W128GH, M29W128GL
2.7
Write Enable (W)
The Write Enable pin, W, controls the Bus Write operation of the memory’s command
interface.
2.8
VPP/Write Protect (VPP/WP)
The VPP/Write Protect pin provides two functions. The VPPH function allows the memory to
use an external high voltage power supply to reduce the time required for program
operations. This is achieved by bypassing the unlock cycles.
The Write Protect function provides a hardware method of protecting the highest or lowest
block (see Section 1: Description). When VPP/Write Protect is Low, VIL, the highest or lowest
block is protected. Program and Erase operations on this block are ignored while VPP/Write
Protect is Low.
When VPP/Write Protect is High, VIH, the memory reverts to the previous protection status
of the highest or lowest block. Program and Erase operations can now modify the data in
this block unless the block is protected using Block protection.
When VPP/Write Protect is raised to VPPH the memory automatically enters the Unlock
Bypass mode (see Section 6.2.6).
When VPP/Write Protect is raised to VPPH, the execution time of the command is lower (see
Table 17: Program, Erase times and Program, Erase endurance cycles).
When VPP/Write Protect returns to VIH or VIL normal operation resumes. During Unlock
Bypass Program operations the memory draws IPP from the pin to supply the programming
circuits. See the description of the Unlock Bypass command in the command interface
section. The transitions from VIH to VPPH and from VPPH to VIH must be slower than tVHVPP
(see Figure 23: Accelerated program timing waveforms).
Never raise VPP/Write Protect to VPPH from any mode except Read mode, otherwise the
memory may be left in an indeterminate state. A 0.1 µF capacitor should be connected
between the VPP/Write Protect pin and the VSS 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 (see IPP1, IPP2, IPP3, IPP4 in Table 25: DC
characteristics).
The VPP/Write Protect pin may be left floating or unconnected because it features an
internal pull-up.
Refer to Table 3 for a summary of VPP/WP functions.
Table 3. VPP/WP functions
VPP/WP
Function
Highest block protected on M29W128GH.
VIL
Lowest block protected on M29W128GL.
VIH
Highest and lowest block unprotected unless a software protection is
activated (see Section 4: Hardware protection).
VPPH
Unlock bypass mode. It supplies the current needed to speed up
programming.
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