User Manual

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Programming
Considerations
CHAPTER 3
This chapter addresses the embedded modules programming considerations.
Note This chapter applies only to development kit customers.
GPIO
General Information
The NS7520 processor supports 16 general purpose I/O (GPIO) lines, some of which are
reserved for specific functions and some of which can be customized. These GPIO lines
fall into three categories:
 Those labeled “Reserved” in the following table are reserved for a specific use
and must not
be reprogrammed, or the unit may not operate correctly. Often,
these lines are not connected to external interfaces.
 Those labeled “Allocated” in the following table are exposed to an external
interface and allocated to a specific use by the software, but they can be
customized safely with code modifications.
 Those labeled “Available” are exposed to an external interface, not controlled
directly by the software, and can be customized.