M29W640GB NUMONYX [Numonyx B.V], M29W640GB Datasheet - Page 20

• Manufacturer Part Number: M29W640GB
• Description: 64 Mbit (8Mb x8 or 4Mb x16, Page) 3V supply Flash memory
• Manufacturer: NUMONYX [Numonyx B.V]

Bus operations
3.5
3.6
3.6.1
3.6.2
20/90
Automatic Standby
If CMOS levels (V
more the memory enters Automatic Standby where the internal Supply Current is reduced to
the Standby Supply Current, I
Read operation is in progress.
Special Bus Operations
Additional bus operations can be performed to read the Electronic Signature and also to
apply and remove Block Protection. These bus operations are intended for use by
programming equipment and are not usually used in applications. They require V
applied to some pins.
Electronic Signature
The memory has two codes, the manufacturer code and the device code, that can be read
to identify the memory. These codes can be read by applying the signals listed in
Bus Operations, BYTE = V
Block Protect and Chip Unprotect
Groups of blocks can be protected against accidental Program or Erase. The Protection
Groups are shown in
can be unprotected to allow the data inside the blocks to be changed.
The V
M29W640GH and M29W640GL, and the four outermost blocks on the M29W640GT and
M29W640GB. When V
remain protected regardless of the Block Protection Status or the Reset/Block Temporary
Unprotect pin status.
Block Protect and Chip Unprotect operations are described in
PP
/Write Protect pin can be used to protect the two outermost blocks on the
CC
± 0.2V) are used to drive the bus and the bus is inactive for 300ns or
Appendix A: Block addresses Table 28
PP
/Write Protect is at V
IL
and
CC2
. The Data Inputs/Outputs will still output data if a Bus
M29W640GH, M29W640GL, M29W640GT, M29W640GB
Table 8: Bus Operations, BYTE = V
IL
the outermost blocks are protected and
and
: Revision
Table
IH
, with A9 set to V
29. The whole chip
history.
ID
Table 7:
to be
ID
.