AM29LV800B datasheet(12/42 Pages) AMD

12 / 42 page

Am29LV800B

P R E L I M I NARY

Table 4.

Am29LV800B Autoselect Codes (High Voltage Method)

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.

Figure 1.

Temporary Sector Unprotect Operation

Description

Mode

CE#

OE#

WE#

A18

A12

A11

A10

DQ8

DQ15

DQ7

DQ0

Manufacturer ID: AMD

VID

XLX

01h

Device ID:

Am29LV800B

(Top Boot Block)

Word

VID

XLX

22h

DAh

Byte

DAh

Device ID:

Am29LV800B

(Bottom Boot

Block)

Word

VID

XLX

22h

5Bh

Byte

5Bh

Sector Protection Verification

VID

XLX

01h

(protected)

00h

(unprotected)

START

Perform Erase or

Program Operations

RESET# = VIH

Temporary Sector

Unprotect Completed

(Note 2)

RESET# = VID

(Note 1)

Notes:

1. All protected sectors unprotected.

2. All previously protected sectors are protected once

again.

21490E-5

AM29LV800B bảng dữ liệu(PDF) 12 Page - Advanced Micro Devices

AM29LV800B bảng dữ liệu(HTML) 12 Page - Advanced Micro Devices

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42

bảng dữ liệu tải về

Link URL