Signal descriptions
M29W320DT, M29W320DB
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.
Note that if V /WP is at V , then the 16 KByte outermost boot block will remain protect
PP
IL
even if RP is at V .
ID
After a Hardware Reset, Bus Read and Bus Write operations cannot begin until Ready/Busy
becomes high-impedance. See Table 15 and Figure 12.
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
IL
x8 mode, 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.
SS
14/56
NUMONYX [ NUMONYX B.V ]
