M29W320EB データシートの表示（PDF） - Numonyx -> Micron

部品番号

コンポーネント説明

メーカー

M29W320EB

32Mbit (4Mbx8 or 2Mbx16, Uniform Parameter Blocks, Boot Block) 3V supply Flash memory

Numonyx -> Micron 

Signal descriptions

M29W320ET, M29W320EB

2.7

Write Enable (W)

The Write Enable, 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 VPP 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 and/or using the Double word or

Quadruple byte Program commands.

The Write Protect function provides a hardware method of protecting the two outermost boot

blocks. When VPP/Write Protect is Low, VIL, the memory protects the two outermost boot

blocks; Program and Erase operations in these blocks are ignored while VPP/Write Protect is

Low, even when RP is at VID.

When VPP/Write Protect is High, VIH, the memory reverts to the previous protection status

of the two outermost boot blocks. Program and Erase operations can now modify the data

in these blocks unless the blocks are protected using Block Protection.

When VPP/Write Protect is raised to VPP the memory automatically enters the Unlock

Bypass mode. 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 VPP and from VPP to VIH must be slower than

tVHVPP, see Figure 16

Never raise VPP/Write Protect to VPP from any mode except Read mode, otherwise the

memory may be left in an indeterminate state.

The VPP/Write Protect pin must not be left floating or unconnected or the device may

become unreliable. A 0.1µF 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,

IPP.

2.9

Reset/Block Temporary Unprotect (RP)

The Reset/Block Temporary Unprotect pin can be used to apply a Hardware Reset to the

memory or to temporarily unprotect all Blocks that have been protected.

Note that if VPP/WP is at VIL, then the two outermost boot blocks will remain protected even

if RP is at VID.

A Hardware Reset is achieved by holding Reset/Block Temporary Unprotect Low, VIL, for at

least tPLPX. After Reset/Block Temporary Unprotect goes High, VIH, the memory will be

ready for Bus Read and Bus Write operations after tPHEL or tRHEL, whichever occurs last.

See the Ready/Busy Output section, Table 16 and Figure 15: Reset/Block Temporary

Unprotect ac waveforms, for more details.

Holding RP at VID will temporarily unprotect the protected Blocks in the memory. Program

and Erase operations on all blocks will be possible. The transition from VIH to VID must be

slower than tPHPHH.

14/63

Share Link: