am49lv6408m Meet Spansion Inc., am49lv6408m Datasheet - Page 21

am49lv6408m

Manufacturer Part Number

am49lv6408m

Description

Stacked Multi-chip Mcp 64 Mbit 4 M ? 16 Bit Flash Memory And 8 Mbit 512k ? 16 Bit Pseudo Static Ram

Manufacturer

Meet Spansion Inc.

Datasheet

1.AM49LV6408M.pdf (63 pages)

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Write Protect (WP#)

The Write Protect function provides a hardware

method of protecting the top two or bottom two sectors

without using V

vided by the WP#/ACC input.

If the system asserts V

vice disables program and erase functions in the first

or last sector independently of whether those sectors

were protected or unprotected using the method de-

scribed in “Sector Group Protection and Unprotection”.

Note that if WP#/ACC is at V

the standby mode, the maximum input load current is

increased. See the table in “DC Characteristics”.

If the system asserts V

vice reverts to whether the top or bottom two sectors

were previously set to be protected or unprotected

using the method described in “Sector Group Protec-

tion and Unprotection”. Note: No external pullup is

necessary since the WP#/ACC pin has internal pullup

to V

November 5, 2003

SA103–SA106

SA107–SA110

SA111–SA114

SA115–SA118

SA119–SA122

SA123–SA126

SA127–SA130

SA131–SA134

SA99–SA102

SA55–SA58

SA59–SA62

SA63–SA66

SA67–SA70

SA71–SA74

SA75–SA78

SA79–SA82

SA83–SA86

SA87–SA90

SA91–SA94

SA95–SA98

Sector

Table 5. Am29LV640MB Bottom Boot

Sector Protection (Continued)

. WP# is one of two functions pro-

01100XXXXX

01101XXXXX

01110XXXXX

01111XXXXX

10000XXXXX

10001XXXXX

10010XXXXX

10011XXXXX

10100XXXXX

10101XXXXX

10110XXXXX

10111XXXXX

11000XXXXX

11001XXXXX

11010XXXXX

11011XXXXX

11100XXXXX

11101XXXXX

11110XXXXX

11111XXXXX

A21–A12

on the WP#/ACC pin, the de-

A D V A N C E

when the device is in

Sector Block Size

256 (4x64) Kbytes

Sector/

Am49LV6408M

I N F O R M A T I O N

Temporary Sector Group Unprotect

(Note: In this device, a sector group consists of four adjacent

sectors that are protected or unprotected at the same time

(see

This feature allows temporary unprotection of previ-

ously protected sector groups to change data in-sys-

tem. The Sector Group Unprotect mode is activated by

setting the RESET# pin to

merly protected sector groups can be programmed or

erased by selecting the sector group addresses. Once

protected sector groups are protected again. Figure 1

shows the algorithm, and Figure 23 shows the timing

diagrams, for this feature.

Notes:

1. All protected sector groups unprotected (If WP# = V

2. All previously protected sector groups are protected

is removed from the RESET# pin, all the previously

the first or last sector will remain protected).

once again.

Table

Figure 1. Temporary Sector Group

5).

Unprotect Operation

Program Operations

Completed (Note 2)

Temporary Sector

Perform Erase or

Group Unprotect

RESET# = V

(Note 1)

START

. During this mode, for-

am49lv6408m Meet Spansion Inc., am49lv6408m Datasheet - Page 21

am49lv6408m

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