W39V040B_07 Datasheet, PDF (8/33 Pages) Winbond – 512K × 8 CMOS FLASH MEMORY WITH LPC INTERFACE

W39V040B
The device may output “1” on DQ5 if the system tries to program “1” to a location that was previously
programmed to “0.” Only the erase operation can change “0” back to “1.” Under this condition, the
device stops the operation, and while the timing limit has been exceeded, DQ5 produces “1.”
Under both these conditions, the system must hardware reset to return to the read mode.
Multi-Chip Operation
Multiple devices can be wired on the single LPC bus. There are four ID pins can be used to support up
to 16 devices. But in order not to violate the BIOS ROM memory space defined by Intel, Winbond
W39V040A will only used 3 ID pins to allow up to 8 devices, 4Mbytes for BIOS code and 4Mbytes for
registers memory space.
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