M29W640FT, M29W640FB
Signal descriptions
2.9
Reset/Block Temporary Unprotect (RP)
The Reset/Block Temporary Unprotect pin can be used to apply a Hardware Reset to the
memory or to temporarily unprotect all Blocks that have been protected.
Note that if V
PP
/WP is at V
IL
, then the two outermost boot blocks will remain protected even
if RP is at V
ID
.
A Hardware Reset is achieved by holding Reset/Block Temporary Unprotect Low, V
IL
, for at
least t
PLPX
. After Reset/Block Temporary Unprotect goes High, V
IH
, the memory will be
ready for Bus Read and Bus Write operations after t
PHEL
or t
RHEL
, whichever occurs last.
See the Ready/Busy Output section,
and
for more
details.
Holding RP at V
ID
will temporarily unprotect the protected Blocks in the memory. Program
and Erase operations on all blocks will be possible. The transition from V
IH
to V
ID
must be
slower than t
PHPHH
.
2.10
Ready/Busy Output (RB)
The Ready/Busy pin is an open-drain output that can be used to identify when the device is
performing a Program or Erase operation. During Program or Erase operations Ready/Busy
is Low, V
OL
. Ready/Busy is high-impedance during Read mode, Auto Select mode and
Erase Suspend mode.
After a Hardware Reset, Bus Read and Bus Write operations cannot begin until Ready/Busy
becomes high-impedance. See
and
for more
details.
The use of an open-drain output allows the Ready/Busy pins from several memories to be
connected to a single pull-up resistor. A Low will then indicate that one, or more, of the
memories is busy.
2.11
Byte/Word Organization Select (BYTE)
The Byte/Word Organization Select pin is used to switch between the x8 and x16 Bus
modes of the memory. When Byte/Word Organization Select is Low, V
IL
, the memory is in
x8 mode, when it is High, V
IH
, the memory is in x16 mode.
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NUMONYX [ NUMONYX B.V ]
