1. GENERAL DESCRIPTION

The W39V040FB is a 4-megabit, 3.3-volt only CMOS flash memory organized as 512K ×8 bits. For flexible erase capability, the 4Mbitsof data are divided into 8 uniformsectors of 64 Kbytes. The device can be programmed and erased in-system with a standard 3.3V power supply. A 12-volt  VPP is required for accelerated program. The unique cell architecture of the W39V040FB results in  fast program/erase operations with extremely low current consumption. This device can operate at two modes, Programmer bus interface mode, FirmwareHub (FWH) bus interface mode. As in the

Programmer interface mode, it acts like the traditionalflash but with a multiplexed address inputs. But in the FWH interface mode, this device complies with the Intel FWH specification. The device can also be programmed and erased using standard EPROM programmers.