M29W320ET, M29W320EB
Signal descriptions
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 . 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 16 and Figure 15: 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.
2.11
2.12
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 , the memory is in x8 mode,
IL
when it is High, V , the memory is in x16 mode.
IH
VCC Supply voltage
V
provides the power supply for all operations (Read, Program and Erase).
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.
A 0.1µF capacitor should be connected between the V Supply voltage pin and the V
CC
SS
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
.
CC3
2.13
VSS Ground
V
is the reference for all voltage measurements. The device features two V pins which
SS
SS
must be both connected to the system ground.
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NUMONYX [ NUMONYX B.V ]
