LM3S9997 Datasheet, PDF (49/1218 Pages) Texas Instruments – Stellaris® LM3S9997 Microcontroller

Stellaris® LM3S9997 Microcontroller
1.1.3
1.1.3.1
■ 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 LM3S9997 controller supports both asynchronous and synchronous serial communications
with:
■ 10/100 Ethernet MAC and PHY with IEEE 1588 PTP hardware support
■ Two CAN 2.0 A/B Controllers
■ USB 2.0 (full speed and low speed) OTG/Host/Device
■ Three UARTs with IrDA and ISO 7816 support (one UART with full modem controls)
■ Two I²C modules
■ Two Synchronous Serial Interface modules (SSI)
■ Integrated Interchip Sound (I²S) Module
The following sections provide more detail on each of these communications functions.
Ethernet Controller (see page 765)
Ethernet is a frame-based computer networking technology for local area networks (LANs). Ethernet
has been standardized as IEEE 802.3. This specification defines a number of wiring and signaling
standards for the physical layer, two means of network access at the Media Access Control
(MAC)/Data Link Layer, and a common addressing format.
June 15, 2010
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Texas Instruments-Advance Information