LM3S1N16 Datasheet, PDF (41/794 Pages) Texas Instruments – Stellaris® LM3S1N16 Microcontroller

Stellaris^® LM3S1N16 Microcontroller
1.3.2.2
1.3.2.3
1.3.3
Flash Memory (see page 293)
The LM3S1N16 microcontroller provides 64 KB of single-cycle on-chip Flash memory. The Flash
memory is organized as a set of 1-KB blocks that can be individually erased. Erasing a block causes
the entire contents of the block to be reset to all 1s. These blocks are paired into a set of 2-KB blocks
that can be individually protected. The blocks can be marked as read-only or execute-only, providing
different levels of code protection. Read-only blocks cannot be erased or programmed, protecting
the contents of those blocks from being modified. Execute-only blocks cannot be erased or
programmed, and can only be read by the controller instruction fetch mechanism, protecting the
contents of those blocks from being read by either the controller or by a debugger.
ROM (see page 291)
The LM3S1N16 ROM is preprogrammed with the following software and programs:
■ Stellaris Peripheral Driver Library
■ Stellaris Boot Loader
■ Advanced Encryption Standard (AES) cryptography tables
■ Cyclic Redundancy Check (CRC) error-detection functionality
The Stellaris Peripheral Driver Library is a royalty-free software library for controlling on-chip
peripherals with a boot-loader capability. The library performs both peripheral initialization and
control functions, with a choice of polled or interrupt-driven peripheral support. In addition, the library
is designed to take full advantage of the stellar interrupt performance of the ARM Cortex-M3 core.
No special pragmas or custom assembly code prologue/epilogue functions are required. For
applications that require in-field programmability, the royalty-free Stellaris Boot Loader can act as
an application loader and support in-field firmware updates.
The Advanced Encryption Standard (AES) is a publicly defined encryption standard used by the
U.S. Government. AES is a strong encryption method with reasonable performance and size. In
addition, it is fast in both hardware and software, is fairly easy to implement, and requires little
memory. The Texas Instruments encryption package is available with full source code, and is based
on lesser general public license (LGPL) source. An LGPL means that the code can be used within
an application without any copyleft implications for the application (the code does not automatically
become open source). Modifications to the package source, however, must be open source.
CRC (Cyclic Redundancy Check) is a technique to validate a span of data has the same contents
as when previously checked. This technique can be used to validate correct receipt of messages
(nothing lost or modified in transit), to validate data after decompression, to validate that Flash
memory contents have not been changed, and for other cases where the data needs to be validated.
A CRC is preferred over a simple checksum (e.g. XOR all bits) because it catches changes more
readily.
Serial Communications Peripherals
The LM3S1N16 controller supports both asynchronous and synchronous serial communications
with:
■ Three UARTs with IrDA and ISO 7816 support
■ Two I²C modules
■ Two Synchronous Serial Interface modules (SSI)
January 21, 2012
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