M29W640FB STMICROELECTRONICS [STMicroelectronics], M29W640FB Datasheet - Page 13

• Manufacturer Part Number: M29W640FB
• Description: 64 Mbit (8Mb x8 or 4Mb x16, Page, Boot Block) 3V Supply Flash Memory
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

M29W640FT, M29W640FB
2.9
2.10
2.11
2.12
Reset/Block Temporary Unprotect (RP)
Ready/Busy Output (RB)
Byte/Word Organization Select (BYTE)
V
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
RP is at V
A Hardware Reset is achieved by holding Reset/Block Temporary Unprotect Low, V
least t
for Bus Read and Bus Write operations after t
Ready/Busy Output section,
and
Holding RP at V
Erase operations on all blocks will be possible. The transition from V
than t
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
Suspend mode.
After a Hardware Reset, Bus Read and Bus Write operations cannot begin until Ready/Busy
becomes high-impedance. See
and
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.
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
it is High, V
V
The Command Interface is disabled when the V
Voltage, V
power up, power down and power surges. If the Program/Erase Controller is programming or
erasing during this time then the operation aborts and the memory contents being altered will
be invalid.
A 0.1µF capacitor should be connected between the V
Ground pin to decouple the current surges from the power supply. The PCB track widths must
be sufficient to carry the currents required during Program and Erase operations, I
CC
CC
Figure 12: Reset/Block Temporary Unprotect AC
Figure 12: Reset/Block Temporary Unprotect AC
provides the power supply for all operations (Read, Program and Erase).
PHPHH
PLPX
OL
Supply Voltage (2.7V to 3.6V)
. Ready/Busy is high-impedance during Read mode, Auto Select mode and Erase
ID
LKO
. After Reset/Block Temporary Unprotect goes High, V
IH
.
.
PP
, the memory is in x16 mode.
. This prevents Bus Write operations from accidentally damaging the data during
/WP is at V
ID
will temporarily unprotect the protected Blocks in the memory. Program and
IL
, then the two outermost boot blocks will remain protected even if
Table 16: Reset/Block Temporary Unprotect AC Characteristics
Table 16: Reset/Block Temporary Unprotect AC Characteristics
PHEL
CC
Supply Voltage is less than the Lockout
or t
Waveforms, for more details.
Waveforms, for more details.
RHEL
CC
Supply Voltage pin and the V
, whichever occurs last. See the
IL
, the memory is in x8 mode, when
IH
, the memory will be ready
IH
to V
ID
2 Signal descriptions
must be slower
CC3
IL
, for at
.
SS
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