AM29F400B datasheet(13/43 Pages) AMD

13 / 43 page

November 1, 2006 21505E5

Am29F400B

D A TA

SH EE T

Table 4.

Am29F400B 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

program and erase operations in previously protected

sectors.

Sector protection/unprotection must be implemented

using programming equipment. The procedure

requires a high voltage (VID) on address pin A9 and

OE#. Details on this method are provided in a supple-

ment, publication number 20185. Contact an AMD

representative to obtain a copy of this document.

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.

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

RESET# pin to VID. During this mode, formerly pro-

tected sectors can be programmed or erased by

selecting the sector addresses. Once VID is removed

from the RESET# pin, all the previously protected

sectors are protected again. Figure 1 shows the algo-

rithm, and Figure 18 shows the timing diagrams, for this

feature.

Figure 1.

Temporary Sector Unprotect Operation

Description

Mode

CE#

OE#

WE#

A17

A12

A11

A10

DQ8

DQ15

DQ7

DQ0

Manufacturer ID: AMD

VID

XLXL

01h

Device ID:

Am29F400B

(Top Boot Block)

Word

VID

XLXL

22h

23h

Byte

23h

Device ID:

Am29F400B

(Bottom Boot Block)

Word

VID

XLXL

22h

ABh

Byte

ABh

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.

AM29F400B 数据表(PDF) 13 Page - Advanced Micro Devices

AM29F400B 数据表(HTML) 13 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 43

数据表下载

链接网址

AM29F400B 数据表(PDF) 13 Page - Advanced Micro Devices

AM29F400B 数据表(HTML) 13 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 43

数据表 下载

链接网址

数据表下载