M29FxxxFT, M29FxxxFB
Signal Descriptions
2.7
2.8
Write Enable
The Write Enable, W, controls the Bus Write operation of the memory’s Command Interface.
Reset/Block Temporary Unprotect
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.
A Hardware Reset is achieved by holding Reset/Block Temporary Unprotect Low, V , for at
IL
least t
. After Reset/Block Temporary Unprotect goes High, V , the memory will be
PLPX
IH
ready for Bus Read and Bus Write operations after t
or t
, whichever occurs last.
PHEL
RHEL
See the Ready/Busy Output section, Table 18.: Reset/Block Temporary Unprotect AC
Characteristics and Figure 23.: Reset/Block Temporary Unprotect AC Waveforms.
Holding RP at V will temporarily unprotect the protected Blocks in the memory. Program
ID
and Erase operations on all blocks will be possible. The transition from V to V must be
IH
ID
slower than t
.
PHPHH
2.9
Ready/Busy Output
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 . Ready/Busy is high-impedance during Read mode, Auto Select mode and
OL
Erase Suspend mode.
After a Hardware Reset, Bus Read and Bus Write operations cannot begin until Ready/Busy
becomes high-impedance. See Table 18.: Reset/Block Temporary Unprotect AC
Characteristics and Figure 23.: Reset/Block Temporary Unprotect AC Waveforms.
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.
2.10
2.11
Byte/Word Organization Select
The Byte/Word Organization Select pin is used to switch between the 8-bit and 16-bit Bus
modes of the memory. When Byte/Word Organization Select is Low, V , the memory is in 8-
IL
bit mode, when it is High, V , the memory is in 16-bit mode.
IH
VCC Supply Voltage
The V Supply Voltage supplies the power for all operations (Read, Program, Erase etc.).
CC
The Command Interface is disabled when the V Supply Voltage is less than the Lockout
CC
Voltage, V
. This prevents Bus Write operations from accidentally damaging the data
LKO
during 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.
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NUMONYX [ NUMONYX B.V ]
