Texas Instruments Tiva TM4C123GH6PM User Manual

System Tick (SysTick)
ROM Location:
ROM_APITABLE is an array of pointers located at 0x0100.0010.
ROM_SYSTICKTABLE is an array of pointers located at ROM_APITABLE[10].
ROM_SysTickPeriodSet is a function pointer located at ROM_SYSTICKTABLE[5].
Parameters:
ui32Period is the number of clock ticks in each period of the SysTick counter; must be be-
tween 1 and 16,777,216, inclusive.
Description:
This function sets the rate at which the SysTick counter wraps; this equates to the number of
processor clocks between interrupts.
Note:
Calling this function does not cause the SysTick counter to reload immediately. If an immediate
reload is required, the NVIC_ST_CURRENT register must be written. Any write to this register
clears the SysTick counter to 0 and will cause a reload with the ui32Period supplied here on
the next clock after the SysTick is enabled.
Returns:
None.
20.2.1.7 ROM_SysTickValueGet
Gets the current value of the SysTick counter.
Prototype:
uint32_t
ROM_SysTickValueGet(void)
ROM Location:
ROM_APITABLE is an array of pointers located at 0x0100.0010.
ROM_SYSTICKTABLE is an array of pointers located at ROM_APITABLE[10].
ROM_SysTickValueGet is a function pointer located at ROM_SYSTICKTABLE[0].
Description:
This function returns the current value of the SysTick counter; this will be a value between the
period - 1 and zero, inclusive.
Returns:
Returns the current value of the SysTick counter.
230 April 8, 2013

Texas Instruments Tiva TM4C123GH6PM Specifications

General

Core	ARM Cortex-M4F
Clock Speed	80 MHz
Flash Memory	256 KB
SRAM	32 KB
GPIO Pins	43
UART	8
I2C	2
SPI/SSI	4
USB	USB 2.0
Timers	6
Communication Interfaces	UART, I2C, SPI, USB
Operating Temperature	-40°C to 85°C
Package	LQFP64

Summary

Boot Loader

Introduction

Explains the ROM-based boot loader and its interfaces for flash updates.

Serial Interfaces

Details the UART, SSI, and I2C interfaces used by the boot loader.

USB Interface

Describes the USB boot loader functionality using the DFU protocol.

Controller Area Network (CAN)

Flash

GPIO

Hibernation Module

Inter-Integrated Circuit (I2C)

Interrupt Controller (NVIC)

Memory Protection Unit (MPU)

Pulse Width Modulator (PWM)

Synchronous Serial Interface (SSI)

System Control

Timer

UART

uDMA Controller

USB Controller

Using USB with the uDMA Controller

Watchdog Timer

Introduction

Functions

Lists and describes API functions for watchdog timer configuration, interrupts, and lock mechanism.