AM29LV800BB70REI View Datasheet(PDF) - Advanced Micro Devices

Part Name

Description

Manufacturer

AM29LV800BB70REI

8 Megabit (1 M x 8-Bit/512 K x 16-Bit) CMOS 3.0 Volt-only Boot Sector Flash Memory

Advanced Micro Devices 

PRELIMINARY

Table 4. Am29LV800B Autoselect Codes (High Voltage Method)

Description

A18 A11

A8

A5

DQ8

to to

to

to

to

Mode CE# OE# WE# A12 A10 A9 A7 A6 A2 A1 A0 DQ15

DQ7

to

DQ0

Manufacturer ID: AMD

L

L

H X X VID X L X L L

X

01h

Device ID:

Word L

L

H

22h

DAh

Am29LV800B

X X VID X L X L H

(Top Boot Block)

Byte L

LH

X

DAh

Device ID:

Am29LV800B

(Bottom Boot

Block)

Word L

L

H

22h

5Bh

X X VID X L X L H

Byte L

L

H

X

5Bh

Sector Protection Verification L

L

H SA X VID X L X H L

X

01h

(protected)

X

00h

(unprotected)

L = Logic Low = VIL, H = Logic High = VIH, SA = Sector Address, X = Don’t care.

Sector Protection/Unprotection

The hardware sector protection feature disables both

program and erase operations in any sector. The hard-

ware sector unprotection feature re-enables both pro-

gram and erase operations in previously protected

sectors.

The device is shipped with all sectors unprotected.

AMD offers the option of programming and protecting

sectors at its factory prior to shipping the device

through AMD’s ExpressFlash™ Service. Contact an

AMD representative for details.

It is possible to determine whether a sector is protected

or unprotected. See “Autoselect Mode” for details.

Sector Protection/unprotection can be implemented via

two methods.

The primary method requires VID on the RESET# pin

only, and can be implemented either in-system or via

programming equipment. Figure 2 shows the algo-

rithms and Figure 23 shows the timing diagram. This

method uses standard microprocessor bus cycle tim-

ing. For sector unprotect, all unprotected sectors must

first be protected prior to the first sector unprotect write

cycle.

The alternate method intended only for programming

equipment requires VID on address pin A9 and OE#.

This method is compatible with programmer routines

written for earlier 3.0 volt-only AMD flash devices. Pub-

lication number 20536 contains further details; contact

an AMD representative to request a copy.

Temporary Sector Unprotect

This feature allows temporary unprotection of previ-

ously protected sectors to change data in-system. The

Sector Unprotect mode is activated by setting the RE-

SET# pin to VID. During this mode, formerly protected

sectors can be programmed or erased by selecting the

sector addresses. Once VID is removed from the RE-

SET# pin, all the previously protected sectors are

protected again. Figure 1 shows the algorithm, and

Figure 22 shows the timing diagrams, for this feature.

START

RESET# = VID

(Note 1)

Perform Erase or

Program Operations

RESET# = VIH

Temporary Sector

Unprotect Completed

(Note 2)

Notes:

21490E-5

1. All protected sectors unprotected.

2. All previously protected sectors are protected once

again.

Figure 1. Temporary Sector Unprotect Operation

12

Am29LV800B

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