W39V040B View Datasheet(PDF) - Winbond

Part Name

Description

Manufacturer

W39V040B

512K × 8 CMOS FLASH MEMORY WITH LPC INTERFACE

Winbond 

W39V040B

7. REGISTER FOR LPC MODE

There are two kinds of registers on this device, the General Purpose Input Registers and Product

Identification Registers. Users can access these registers through respective address in the 4Gbytes

memory map. There are detail descriptions in the sections below.

7.1 General Purpose Inputs Register for LPC Mode

This register reads the FGPI[4:0] pins on the W39V040B.This is a pass-through register which can read

via memory address FBC0100(hex). Since it is pass-through register, there is no default value.

GPI Register Table

BIT

7−5

4

3

2

1

0

FUNCTION

Reserved

Read FGPI4 pin status

Read FGPI3 pin status

Read FGPI2 pin status

Read FGPI1 pin status

Read FGPI0 pin status

7.2 Identification Input Pins ID[3:0]

These pins are part of mechanism that allows multiple parts to be used on the same bus. The boot

device should be 0000b. And all the subsequent parts should use the up-count strapping. Note that a

1M byte ROM will occupy two Ids. For example: a 1MByte ROM's ID is 0000b, the next ROM's ID is

0010b. These pins all are pulled down with internal resistor.

7.3 Product Identification Registers

In the LPC interface mode, a read from FBC, 0000(hex) can output the manufacturer code, DA(hex). A

read from FBC, 0001(hex) can output the device code 54(hex).

There is an alternative software method (six commands bytes) to read out the Product Identification in

both the Programmer interface mode and the LPC interface mode. Thus, the programming equipment

can automatically matches the device with its proper erase and programming algorithms.

In the software access mode, a six-byte (or JEDEC 3-byte) command sequence can be used to access

the product ID for programmer interface mode. A read from address 0000(hex) outputs the

manufacturer code, DA(hex). A read from address 0001(hex) outputs the device code, 54(hex). The

product ID operation can be terminated by a three-byte command sequence or an alternate one-byte

command sequence (see Command Definition table for detail).

Publication Release Date: April 14, 2005

-8-

Revision A3

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