Preliminary
PowerNP NPe405L Embedded Processor Data Sheet
Signal Description
The following table provides a summary of the number of package pins (balls) associated with each functional
interface group.
Pin Summary
Group
No. of Pins
Nonmultiplexed Signals
Multiplexed Signals
Total Signal Pins
167
48
215
1
AV
DD
OV
16
DD
V
8
48
36
0
DD
Gnd
Gnd (and thermal)
Reserved
Total Pins
324
Multiplexed pins
In the table “Signal Functional Description” on page 32, each external signal is listed along with a short
description of the signal function. The signals are grouped together according to their function. Some signals
are multiplexed on the same package pin (ball) so that the pin can be used for different functions. In most
cases, the signal name is shown in this table unaccompanied by multiplexed signal names that may be
associated with it. In cases where multiplexed signals are in the same functional group, the names appear as
a default signal followed by secondary signals in square brackets (for example, EMC0TxErr[EMC0Tx1En]).
Active-low signals (for example, RAS) are marked with an overline. Any signal that is not the primary (default)
signal on a multiplexed pin is shown in square brackets.
The active signal on a multiplexed pin is controlled by programming. It is expected that in any single
application, a particular pin will always be programmed to serve the same function. The flexibility of
multiplexing allows a single chip to offer a richer pin selection than would otherwise be possible.
Initialization Strapping
One group of pins is used as strapped inputs during system reset. These pins function as strapped inputs
only during reset and are used for other functions during normal operation (see “Initialization” on page 51).
Note that the use of these pins for strapping is not considered multiplexing since the strapping function is not
programmable.
Pull-up and Pull-down Resistors
Pull-up and pull-down resistors are used for strapping during reset and to retain unused or undriven inputs in
an appropriate state. The recommended pull-up value of 3kΩ to +3.3V (10kΩ to +5V can be used on 5V
tolerant I/Os) and pull-down value of 1kΩ to GND, applies only to individually terminated signals. To prevent
possible damage to the device, I/Os capable of becoming outputs must never be tied together and terminated
through a common resistor.
If your system-level test methodology permits, input-only signals can be connected together and terminated
through either a common resistor or directly to +3.3V or GND. When a resistor is used, its value must ensure
30
AMCC [ APPLIED MICRO CIRCUITS CORPORATION ]
