EN29LV800B70RT View Datasheet(PDF) - Eon Silicon Solution Inc.

Part Name

Description

Manufacturer

EN29LV800B70RT

8 Megabit (1024K x 8-bit / 512K x 16-bit) Flash Memory Boot Sector Flash Memory, CMOS 3.0 Volt-only

Eon Silicon Solution Inc. 

EN29LV800

To access the autoselect codes in-system; the host system can issue the autoselect command via

the command register, as shown in the Command Definitions table. This method does not require

VID. See “Command Definitions” for details on using the autoselect mode.

Write Mode

Write operations, including programming data and erasing sectors of memory, require the host

system to write a command or command sequence to the device. Write cycles are initiated by

placing the byte or word address on the device’s address inputs while the data to be written is input

on DQ[7:0] in Byte Mode (BYTE# = L) or on DQ[15:0] in Word Mode (BYTE# = H). The host system

must drive the CE# and WE# pins Low and the OE# pin High for a valid write operation to take place.

All addresses are latched on the falling edge of WE# and CE#, whichever happens later. All data is

latched on the rising edge of WE# or CE#, whichever happens first. The system is not required to

provide further controls or timings. The device automatically provides internally generated program /

erase pulses and verifies the programmed /erased cells’ margin. The host system can detect

completion of a program or erase operation by observing the RY/BY# pin, or by reading the DQ[7]

(Data# Polling) and DQ[6] (Toggle) status bits.

The ‘Command Definitions’ section of this document provides details on the specific device

commands implemented in the EN29LV800.

Sector Protection/Unprotection

The hardware sector protection feature disables both program and erase operations in any sector. The

hardware sector unprotection feature re-enables both program and erase operations in previously

protected sectors.

There are two methods to enabling this hardware protection circuitry. The first one requires only that

the RESET# pin be at VID and then standard microprocessor timings can be used to enable or

disable this feature. See Flowchart 7a and 7b for the algorithm and Figure 12 for the timings.

When doing Sector Unprotect, all the other sectors should be protected first.

The second method is meant for programming equipment. This method requires VID be applied to

both OE# and A9 pin and non-standard microprocessor timings are used. This method is described

in a separate document called EN29LV800 Supplement, which can be obtained by contacting a

representative of Eon Silicon Devices, Inc.

Temporary Sector Unprotect

This feature allows temporary unprotection of previously protected

sector groups to change data while in-system. The Sector

Unprotect mode is activated by setting the RESET# pin to VID.

During this mode, formerly protected sectors can be programmed

or erased by simply selecting the sector addresses. Once is

removed from the RESET# pin, all the previously protected sectors

are protected again. See accompanying figure and timing

diagrams for more details.

Notes:

1. All protected sectors unprotected.

2. Previously protected sectors protected

again.

Start

Reset#=VID (note 1)

Perform Erase or Program

Operations

Reset#=VIH

Temporary Sector

Unprotect Completed (note 2)

4800 Great America Parkway, Suite 202

8

Santa Clara, CA 95054

Rev 0.4 Release Date: 2002/01/29

Tel: 408-235-8680

Fax: 408-235-8685

Share Link: