HY29LV800 Datasheet, PDF(9/40 Page) Hynix Semiconductor – 8 Mbit (1M x 8/512K x 16) Low Voltage Flash Memory

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HY29LV800 Datasheet, PDF (9/40 Pages) Hynix Semiconductor – 8 Mbit (1M x 8/512K x 16) Low Voltage Flash Memory

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Sector Protect Operation

The hardware sector protection feature disables

both program and erase operations in any sector

or combination of sectors. This function can be

implemented either in-system or by using program-

ming equipment.

The Sector Protect procedure requires VID on the

RESET# pin and uses standard microprocessor

bus cycle timing to implement sector protection.

The flow chart in Figure 1 illustrates the algorithm.

The HY29LV800 is shipped with all sectors un-

protected. It is possible to determine whether a

sector is protected or unprotected. See the Elec-

tronic ID Mode section for details.

Sector Unprotect Operation

The hardware sector unprotection feature re-en-

ables both program and erase operations in pre-

viously protected sectors. This function can be

implemented either in-system or by using program-

ming equipment. Note that to unprotect any sec-

tor, all unprotected sectors must first be protected

prior to the first sector unprotect write cycle. Also,

the unprotect procedure will cause all sectors to

become unprotected, thus, sectors that require

HY29LV800

protection must be protected again after the un-

protect procedure is run.

The Sector Unprotect procedure requires VID on

the RESET# pin and uses standard microproces-

sor bus cycle timing to implement sector unpro-

tection. The flow chart in Figure 2 illustrates the

algorithm.

Temporary Sector Unprotect Operation

This feature allows temporary unprotection of pre-

viously protected sectors to allow changing the

data in-system. Sector Unprotect mode is activated

by setting the RESET# pin to VID. While in this

mode, formerly protected sectors can be pro-

grammed or erased by invoking the appropriate

commands (see Device Commands section).

Once VID is removed from RESET#, all the previ-

ously protected sectors are protected again. Fig-

ure 3 illustrates the algorithm.

Electronic ID Operation (High Voltage Method)

The Electronic ID mode provides manufacturer and

device identification and sector protection verifi-

cation through codes output on DQ[15:0]. This

mode is intended primarily for programming equip-

ment to automatically match a device to be pro-

START

RESET# = VID

Wait 1 us

Write 0x60 to device

TRYCNT = 1

Set Address:

A[18:12] = Sector to Protect

A[6] = 0, A[1] = 1, A[0] = 0

Write 0x60 to Address

Wait 150 us

Write 0x40 to Address

Read from Address

Data = 0x01?

YES

Protect Another NO

Sector?

YES

TRYCNT = 25? YES

Increment TRYCNT

RESET# = VIH

Write Reset Command

SECTOR PROTECT

COMPLETE

DEVICE FAILURE

Figure 1. Sector Protect Algorithm

Rev. 1.0/Nov. 01

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