TM4C1292NCPDT Datasheet, PDF (595/1822 Pages) Texas Instruments – Tiva Microcontroller

Tiva^™ TM4C1292NCPDT Microcontroller
8.2.2.1
8.2.2.2
firmware upgrade mechanism (by calling back to the boot loader). The Peripheral Driver Library
APIs in ROM can be called by applications, reducing Flash memory requirements and freeing the
Flash memory to be used for other purposes (such as additional features in the application). Advanced
Encryption Standard (AES) is a publicly defined encryption standard used by the U.S. Government.
Cyclic Redundancy Check (CRC) is a technique to validate whether a block of data has the same
contents as when previously checked.
Note: CRC software program are available in TivaWare for backward-compatibility. A device that
has enhanced CRC integrated module should utilize this hardware for best performance.
Please refer to “Cyclical Redundancy Check (CRC)” on page 939 for more information.
Boot Configuration
After Power-On-Reset (POR) and device initialization occurs, the hardware loads the stack pointer
from either flash or ROM based on the presence of an application in flash and the state of the EN
bit in the BOOTCFG register. If the flash address 0x0000.0004 contains an erased word (value
0xFFFF.FFFF) or the EN bit is of the BOOTCFG register is clear, the stack pointer and reset vector
pointer are loaded from ROM at address 0x0100.0000 and 0x0100.0004, respectively. The boot
loader executes and configures the available boot slave interfaces and waits for an external memory
to load its software. The boot loader uses a simple packet interface to provide synchronous
communication with the device. The speed of the boot loader is determined by the internal oscillator
(PIOSC) frequency. The following serial interfaces can be used:
■ UART0
■ SSI0
■ I²C0
■ USB
If the check of the Flash at address 0x0000.0004 contains a valid reset vector value and the EN bit
in the BOOTCFG register is set, the stack pointer and reset vector values are fetched from the
beginning of flash. This application stack pointer and reset vector are loaded and the processor
executes the application directly. Otherwise, the stack pointer and reset vector values are fetched
from the beginning of ROM.
TivaWare Peripheral Driver Library
The TivaWare Peripheral Driver Library contains a file called driverlib/rom.h that assists with
calling the peripheral driver library functions in the ROM. The detailed description of each function
is available in the Tiva™ C Series TM4C129x ROM User’s Guide (literature number SPMU363).
See the "Using the ROM" chapter of the TivaWare™ Peripheral Driver Library for C Series User's
Guide (literature number SPMU298) for more details on calling the ROM functions and using
driverlib/rom.h.
A table at the beginning of the ROM points to the entry points for the APIs that are provided in the
ROM. Accessing the API through these tables provides scalability; while the API locations may
change in future versions of the ROM, the API tables do not. The tables are split into two levels; the
main table contains one pointer per peripheral which points to a secondary table that contains one
pointer per API that is associated with that peripheral. The main table is located at 0x0100.0010,
right after the Cortex-M4F vector table in the ROM.
DriverLib functions are described in detail in the TivaWare™ Peripheral Driver Library for C Series
User's Guide (literature number SPMU298).
Additional APIs are available for graphics and USB functions, but are not preloaded into ROM. The
TivaWare Graphics Library provides a set of graphics primitives and a widget set for creating graphical
user interfaces on Tiva™ C Series microcontroller-based boards that have a graphical display (for
June 18, 2014
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