w49v002a Winbond Electronics Corp America, w49v002a Datasheet - Page 5

• Manufacturer Part Number: w49v002a
• Description: 256k X 8 Cmos Flash Memory With Lpc Interface
• Manufacturer: Winbond Electronics Corp America

Memory Address Map
There are 8M bytes space reserved for BIOS Addressing. The ROM will respond to 256K byte pages
whenever the memory address rang is within the top 4M bytes and bottom 128K bytes.
The 32bit address space is as below:
General Purpose Inputs Register
This register reads the GPI[4:0] pins on the W49V002A.This is a pass-through register which can read
via memory address FFBC0100(hex). Since it is pass-through register, there is no default value.
Product Identification
The product ID operation outputs the manufacturer code and device code. Programming equipment
automatically matches the device with its proper erase and programming algorithms.
The manufacturer and device codes can be accessed by software operation. In the software access
mode, a six-byte (or JEDEC 3-byte) command sequence can be used to access the product ID. A read
from address 0000(hex) outputs the manufacturer code, DA(hex). A read from address 0001(hex) outputs
the device code, B0(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).
4M Byte BIOS ROM
128K Byte BIOS ROM
Registers
7-5
Bit
4
3
2
1
0
Block
Reserved
Read GPI4 pin status
Read GPI3 pin status
Read GPI2 pin status
Read GPI1 pin status
Read GPI0 pin status
Function
FFFF,FFFFh:FFC0,0000h
000F,FFFFh:000E,0000h
FFBC,0100h
Address Range
- 5 -
Preliminary W49V002A
Publication Release Date: April 2001
Revision A1