M29W128GH, M29W128GL
Signal descriptions
2.9
Reset (RP)
The Reset pin can be used to apply a Hardware Reset to the memory.
A Hardware Reset is achieved by holding Reset Low, V , for at least t
. After Reset goes
PLPX
IL
High, V , the memory will be ready for Bus Read and Bus Write operations after t
or
IH
PHEL
t
, whichever occurs last. See Section 2.10: Ready/Busy output (RB), Table 29: Reset
RHEL
AC characteristics, Figure 21 and Figure 22 for more details.
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 (see Table 20: Status Register bits). Ready/Busy is high-impedance during
OL
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 Table 29: Reset AC characteristics, Figure 21 and
Figure 22.
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)
It is used to switch between the x 8 and x 16 Bus modes of the memory. When Byte/word
organization select is Low, V , the memory is in x 8 mode, when it is High, V , the memory
IL
IH
is in x 16 mode.
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 0.1 µF 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 (see
I
, I
, I
in Table 25: DC characteristics).
CC1 CC2 CC3
2.13
VCCQ input/output supply voltage
V
provides the power supply to the I/O pins and enables all outputs to be powered
CCQ
independently from V
.
CC
15/94
NUMONYX [ NUMONYX B.V ]
