Lab Exercise
Contents
1. TI ARM Lab 5 National API and Interrupts Science Foundation Funded in part by a grant from the National Science Foundation DUE 1068182 Acknowledgements Developed by Craig Kief Brian Zufelt and Jacy Bitsoie at the Configurable Space Microsystems Innovations amp Applications Center COSMIAC Co Developers are Bassam Matar from Chandler Gilbert and Karl Henry from Drake State Funded by the National Science Foundation NSF Lab Summary This lab introduces the concepts of the API and interrupts Lab Goal The goal of this lab is to continue to build upon the skills learned from previous labs This lab helps the student to continue to gain new skills and insight on the C code syntax and how it is used in the TI implementation of the ARM processor Each of these labs add upon the previous labs and it is the intention of the authors that the student will build with each lab a better understanding of the ARM processor and basic C code Even though these tutorials assume the student has not entered with a knowledge of C code it is the desire that by the time the student completes the entire series of tutorials that they will have a sufficient knowledge of C code so as to be able to accomplish useful projects on the ARM processor Learning Objectives The student should begin to become familiar with the concept of APIs and interrupts API an abbreviation of application program interface is a set of routines protocols and tools for buildin2. Hit red square to cancel the debugger and return to CCS edit mode In main c add the following code right before the while 1 loop Setting up interrupts makes BTN 1 the interrupt lab activity IntEnable INT_GPIOD_TM4C123 sets the interrupt controller to interrupt on GPIO port D GPIOPinIntEnable GPIO_PORTD_BASE GPIO_PIN_2 BTN 1 GPIOIntTypeSet GPIO_PORTD_BASE GPIO_PIN_2 GPIO_RISING_EDGE Rising Edge IntMasterEnable Turns on all interrupts At bottom of main c before the final type paste this in void GPIO_PORTD_isr void GPIOPinIntClear GPIO_PORTD_BASE GPIO_PIN_2 Clear Interrupts while GPIOPinRead GPIO_PORTD_BASE GPIO_PIN_2 Listen for BTN 1 All LED Blink GPIOPinWrite GPIO_PORTC_BASE GPIO_PIN_6 GPIO_PIN_7 OxFF GPIOPinWrite GPIO_PORTD_BASE GPIO_PIN_6 OxFF GPIOPinWrite GPIO_PORTB_BASE GPIO_PIN_5 0x20 GPIOPinWrite GPIO_PORTF_BASE GPIO_PIN_1 GPIO_PIN_2 GPIO_PIN_3 OxFF White Output SysCtlDelay 2000000 GPIOPinWrite GPIO_PORTC_BASE GPIO_PIN_6 GPIO_PIN_7 0x00 GPIOPinWrite GPIO_PORTD_BASE GPIO_PIN_6 0x00 GPIOPinWrite GPIO_PORTB_BASE GPIO_PIN_5 0x00 GPIOPinWrite GPIO_PORTF_BASE GPIO_PIN_1 GPIO_PIN_2 GPIO_PIN_3 0x00 White Output SysCtlDelay 2000000 What we have done is add in the ISR It is the exact same code as above but now is acted upon by a push of the button immediately instead of after the finish of t
3. If the auto installer was used it will automatically load up shells that are were used for the workshop The student will know if they have used the auto installer program as they will be presented with a picture as shown in Figure 3 where the shells of all lab projects are installed Be aware though that there are no solutions folders These were only created to assist with the internal tutorial development Project Explorer 2 BH 7S i Lab 2 2 Lab 3 1S Lab 4 i Lab 5 Active Debug 1 Lab 6 i Lab7 i Lab 8 1S Lab 9 Figure 3 Project Options Figure 3 shows the shell of the projects This has created the shell for all the tutorials Expand the ATE_LAB5 project and open the main c file 13 4 ERR RK RK RK RR RK RK KK KK KA 15Chip type ARM TM4C123GH6PI 16 Program type Firmware 17Core Clock frequency 80 000000 MHz 18 KKK KKK KKK KK KKK KKK KK KKK KK KKK KKK KKK KKK KKK EKRKG 19 20 include 21 include 22 include 23 include 24 include 25 include 26 include 27 include 28 include 29 include 30 include 31 include 32 include 33 include lt stdbool h gt lt stdint h gt inc tm4c123gh6pm h inc hw_memmap h inc hw_types h driverlib gpio h driverlib pin_map h driverlib sysctl h driverlib uart h inc hw_i2c h driverlib i2c h inc hw_ints h driverlib interrupt h driverlib timer h lab activity 34 Figure 4 Lab 5 Expanded As can be s
4. SysCtlPeripheralEnable SYSCTL_PERIPH_GPIOC PORTC GPIOPinTypeGPIlOOutput GPIO_PORTC_BASE GPIO_PIN_6 GPIO_PIN_7 LED 1 LED 2 SysCtlPeripheralEnable SYSCTL_PERIPH_GPIOB PORTB GPIOPinTypeGPIOOutput GPIO_PORTB_BASE GPIO_PIN_5 LED 4 SysCtlPeripheralEnable SYSCTL_PERIPH_GPIOD PORT D GPIOPinTypeGPIlOOutput GPIO_PORTD_BASE GPIO_PIN_6 LED 3 GPIOPinTypeGPIOInput GPIO_PORTD_BASE GPIO_PIN_ 2 BTN 1 SysCtlPeripheralEnable SYSCTL_PERIPH_GPIOF PORT F GPIOPinTypeGPIOOutput GPIO_PORTF_BASE GPIO_PIN_1 GPIO_PIN_2 GPIO_PIN_3 RGB LED on Launchpad SysCtlPeripheralEnable SYSCTL_PERIPH_GPIOA PORT A GPIOPinTypeGPIOInput GPIO_PORTA BASE GPIO_PIN 6 Switch 2 loop while 1 lab activity if GPIOPinRead GPIO_PORTA_BASE GPIO_PIN_6 Listen for the switch Removed to run code in complete else GPIOPinWrite GPIO_PORTF_BASE GPIO_PIN_1 GPIO_PIN_2 GPIO_PIN_3 4 LED Blue on Launchpad Cycle through the LEDs on the Orbit board GPIOPinWrite GPIO_PORTC_BASE GPIO_PIN_6 GPIO_PIN_7 0x40 LED 1 on LED 2 Off GPIOPinWrite GPIO_PORTD_BASE GPIO_PIN_6 0x00 LED 3 off Note different PORT GPIOPinWrite GPIO_PORTB_BASE GPIO_PIN_5 0x00 LED 4 off SysCtIDelay 6000000 Delay Replaces for LOOP GPIOPinWrite GPIO_PORTC_BASE GPIO_PIN_6 GPIO_PIN_7 0x80 LED 1 OFF LED 2 on SysCtIDelay 6000000 Delay Replaces for LOOP GPIOPinWrite GPIO_PORTC_BASE GPIO_PIN_6 GPIO_PIN_7 0x00
5. GPIO_PORTD_BASE GPIO_PIN_6 0x00 LED 3 off Note different PORT GPIOPinWrite GPIO_PORTB_BASE GPIO_PIN_5 0x00 LED 4 off SysCtIDelay 6000000 Delay Replaces for LOOP GPIOPinWrite GPIO_PORTC_BASE GPIO_PIN_6 GPIO_PIN_7 0x80 LED 1 OFF LED 2 on SysCtIDelay 6000000 Delay Replaces for LOOP GPIOPinWrite GPIO_PORTC_BASE GPIO_PIN_6 GPIO_PIN_7 0x00 LED 1 off LED 2 off GPIOPinWrite GPIO_PORTD_BASE GPIO_PIN_6 0x40 LED 3 on SysCtIDelay 6000000 Delay Replaces for LOOP GPIOPinWrite GPIO_PORTD_BASE GPIO_PIN_6 0x00 LED 3 off GPIOPinWrite GPIO_PORTB_BASE GPIO_PIN_5 0x20 LED 4 on SysCtIDelay 6000000 Delay Replaces for LOOP else GPIOPinWrite GPIO_PORTF_BASE GPIO_PIN_1 GPIO_PIN_2 GPIO_PIN_3 8 LED Green on Launchpad Cycle through the LEDs on the Orbit board GPIOPinWrite GPIO_PORTC_BASE GPIO_PIN_6 GPIO_PIN_7 0x00 LED 1 off LED 2 Off GPIOPinWrite GPIO_PORTD_BASE GPIO_PIN_6 0x00 LED 3 off Note different PORT GPIOPinWrite GPIO_PORTB_BASE GPIO_PIN_5 0x20 LED 4 on SysCtIDelay 6000000 Delay Replaces for LOOP GPIOPinWrite GPIO_PORTB_BASE GPIO_PIN_5 0x00 LED 4 off GPIOPinWrite GPIO_PORTD_BASE GPIO_PIN_6 0x40 LED 3 on SysCtIDelay 6000000 Delay Replaces for LOOP GPIOPinWrite GPIO_PORTC_BASE GPIO_PIN_6 GPIO_PIN_7 0x80 LED 1 OFF LED 2 on GPIOPinWrite GPIO_PORTD_BASE GPIO_PIN_6 0x00 LED 3 off SysCtIDelay 6000000 Delay
6. Replaces for LOOP GPIOPinWrite GPIO_PORTC_BASE GPIO_PIN_6 GPIO_PIN_7 0x40 LED 1 on LED 2 Off SysCtIDelay 6000000 Delay Replaces for LOOP 13 lab activity ifdef Lab5 Problem endif while GPIOPinRead GPIO_PORTD_BASE GPIO_PIN_2 Listen for BTN 1 All LED Blink GPIOPinWrite GPIO_PORTC_BASE GPIO_PIN_6 GPIO_PIN_7 OxFF GPIOPinWrite GPIO_PORTD_BASE GPIO_PIN_6 OxFF GPIOPinWrite GPIO_PORTB_BASE GPIO_PIN_5 0x20 GPIOPinWrite GPIO_PORTF_ BASE GPIO PIN 1 GPIO_PIN_2 GPIO_PIN_3 OxFF White Output SysCtIDelay 2000000 GPIOPinWrite GPIOPinWrite GPIOPinWrite GPIOPinWrite GPIO_PORTC_BASE GPIO_PIN_6 GPIO_PIN_7 0x00 GPIO_PORTD_BASE GPIO_PIN_6 0x00 GPIO_PORTB_BASE GPIO_PIN_5 0x00 GPIO_PORTF_BASE GPIO_PIN_1 GPIO PIN 2 GPIO_PIN_3 0x00 White Output lt lt SysCtlDelay 2000000 void GPIO_PORTD isr void GPIOIntClear GPIO_PORTD_BASE GPIO_PIN_2 Clear Interrupts while GPIOPinRead GPIO_PORTD_BASE GPIO PIN 2 Listen for BTN 1 All LED Blink GPIOPinWrite GPIO_PORTC_BASE GPIO_PIN_6 GPIO_PIN_7 OxFF GPIOPinWrite GPIO_PORTD_BASE GPIO_PIN_6 OxFF GPIOPinWrite GPIO_PORTB_BASE GPIO_PIN_5 0x20 GPIOPinWrite GPIO_PORTF BASE GPIO PIN 1 GPIO PIN _2 GPIO_PIN_3 OxFF White Output SysCtlDelay 2000000 GPIOPinWrite GPIOPinWrite GPIOPinWrite GPIOPinWrite GPIO_PORTC_BASE GPIO_PIN_6 GPIO_PIN_7 0x00 GPIO_PORTD_BASE GPIO_PIN_6 0x00
7. This is what happens when you have to immediately stop what is going on and jump for an error When button one is released it goes immediately back to where it came from When done remember to hit the red square to exit debug mode Challenge Change from Button 1 to Switch 2 lab activity Attachment 1 main c file before addition of interrupt RRR AR AAA HAR AAAI HAA AAAI AAR EA AAA AAR EA AAA RAR AA Project Orbit Lab 5 ATE int Version 1 0 Date 2 20 2013 Author Brian Zufelt Craig Kief Company COSMIAC UNM Comments This source introduces the concept of interrupts Building on Lab 4 the call to blink the LEDs will execute as soon as BTN 1 is pressed SERA AACA A AACA AR A AACA A A AACA A AEA AACA KA Chip type ARM TM4C123GH6PM Program type Firmware Core Clock frequency 80 000000 MHz FEC OO CIOS ICSI AAAI AAAI AAAI AA AA AAA AA include lt stdbool h gt include lt stdint h gt include inc tm4c123gh6pm h include inc hw_memmap h include inc hw_types h include driverlib gpio h include driverlib pin_map h include driverlib sysctl h include driverlib uart h include inc hw_i2c h include driverlib i2c h include inc hw_ints h include driverlib interrupt h include driverlib timer h void main void Setting the internal clock SysCtlClockSet SYSCTL_SYSDIV_5 SYSCTL_USE_PLL SYSCTL_XTAL_16MHZ SYSCTL_OSC_MAIN Enable Peripheral ports for input output
8. GPIO_PORTB_BASE GPIO_PIN_5 0x00 GPIO_PORTF_BASE GPIO PIN 1 GPIO PIN 2 GPIO_PIN_3 0x00 White Output annann SysCtlDelay 2000000 14 lab activity Attachment 3 Block Diagram of the Pins Used in Projects 2 2 2 202 21 2 Pin Number 7 6543210 CORE Hex Binary 000 oo ooo PA7 Port A Pin 7 To energize send 0x80 UART PA ORX IN CIRCUIT DEBUGGER USB Pc PA 1TX ICD PA 6_ ORBIT SW 2 se ORBITSW1 12C GPIO B PBS ORBIT LED 4 vec SCL E a PB2 TEMP ACCEL SENSOR Device ID PC6 Device ID 0x1D GPIO C ORBIT LED 1 Ox4f WROx3A PC7 ORBITLED 2 RD 0x3B GPIO D PD6_ ORBIT LED 3 ORBIT PD2 ORBITBTN 1 GPIO E CEO ORBIT BTN 2 PFO Tiva Launchpad BTN 2 PF1 Tiva Launchpad LED RED PF2 _ Tiva Launchpad LED BLUE PF3 Tiva Launchpad LED GREEN 1 PFA Tiva Launchpad BTN 1 15
9. LED 1 off LED 2 off GPIOPinWrite GPIO_PORTD_BASE GPIO_PIN_6 0x40 LED 3 on SysCtIDelay 6000000 Delay Replaces for LOOP GPIOPinWrite GPIO_PORTD_BASE GPIO_PIN_6 0x00 LED 3 off GPIOPinWrite GPIO_PORTB_BASE GPIO_PIN_5 0x20 LED 4 on SysCtIDelay 6000000 Delay Replaces for LOOP GPIOPinWrite GPIO_PORTF_BASE GPIO_PIN_1 GPIO_PIN_2 GPIO_PIN_3 8 LED Green on Launchpad Cycle through the LEDs on the Orbit board GPIOPinWrite GPIO_PORTC_BASE GPIO_PIN_6 GPIO_PIN_7 0x00 LED 1 off LED 2 Off GPIOPinWrite GPIO_PORTD_BASE GPIO_PIN_6 0x00 LED 3 off Note different PORT GPIOPinWrite GPIO_PORTB_BASE GPIO_PIN_5 0x20 LED 4 on SysCtIDelay 6000000 Delay Replaces for LOOP GPIOPinWrite GPIO_PORTB_BASE GPIO_PIN_5 0x00 LED 4 off GPIOPinWrite GPIO_PORTD_BASE GPIO_PIN_6 0x40 LED 3 on SysCtIDelay 6000000 Delay Replaces for LOOP GPIOPinWrite GPIO_PORTC_BASE GPIO_PIN_6 GPIO_PIN_7 0x80 LED 1 OFF LED 2 on GPIOPinWrite GPIO_PORTD_BASE GPIO_PIN_6 0x00 LED 3 off SysCtIDelay 6000000 Delay Replaces for LOOP GPIOPinWrite GPIO_PORTC_BASE GPIO_PIN_6 GPIO_PIN_7 0x40 LED 1 on LED 2 Off SysCtIDelay 6000000 Delay Replaces for LOOP while GPIOPinRead GPIO_PORTD_BASE GPIO PIN 2 Listen for BTN 1 All LED Blink GPIOPinWrite GPIO_PORTC_BASE GPIO_PIN_6 GPIO_PIN_7 OxFF GPIOPinWrite GPIO_PORTD_BASE GPIO_PIN_6 OxFF GPIOPinWrite GPIO_PORTB_BASE GPIO_
10. M Adobe Acrobat D 168 KB SE SW EK TM4C1294XL BOOSTXL KENTEC 6 9 2014 2 58 PM Adobe Acrobat D 215 KB FE SW EK TM4C1294XL BOOSTXL SENSHU 6 9 2014 2 58 PM Adobe Acrobat D 178 KB we SW EK TM4C1294XL UG 2 1 0 12573 pdf 6 9 2014 2 58 PM Adobe Acrobat D 246 KB E SW TM4C BOOTLDR UG 2 1 0 12573 pdf 6 9 2014 2 58 PM Adobe Acrobat D 404 KB p SW TM4C DRL UG 2 1 0 12573 pdf 6 9 2014 2 58 PM Adobe Acrobat D 5 966 KB FE SW TM4C EXAMPLES UG 2 1 0 12573 pdf 6 9 2014 2 58 PM Adobe Acrobat D 200 KB SW TM4C GRL UG 2 1 0 12573 pdf 6 9 2014 2 58 PM Adobe Acrobat D 1 794 KB pi SW TM4C IQMATH UG 2 1 0 12573 pdf 6 9 2014 2 58 PM Adobe Acrobat D 329 KB Figure 1 700 Page Users Guide In the documentation of the installation you performed there is a 6G pdf file called the TivaWare Peripheral Driver Library User s Guide This 700 page document contains a complete list of these functions and how to use them As an example you can search for GPIOPinWrite These functions are contained on Read Only Memory ROM contained on the microcontroller The beauty of this is that you never have to work hard to find these API functions They are always on the microcontroller chip The beauty of the API functions are that they reduce the amount of resources used thus the amount of power consumed This is very important for low power applications For example in previous labs we used a for loop for creating a time delay In fact there is a delay func
11. PIN_5 0x20 GPIOPinWrite GPIO_PORTF_BASE GPIO PIN 1 GPIO_PIN_2 GPIO_PIN_3 OxFF White Output 10 lab activity SysCtIDelay 2000000 GPIOPinWrite GPIO_PORTC_BASE GPIO_PIN_6 GPIO_PIN_7 0x00 GPIOPinWrite GPIO_PORTD_BASE GPIO_PIN_6 0x00 GPIOPinWrite GPIO_PORTB_BASE GPIO_PIN_5 0x00 GPIOPinWrite GPIO_PORTF_BASE GPIO_PIN_1 GPIO_PIN_2 GPIO_PIN_3 0x00 White Output SysCtIDelay 2000000 11 Attachment 2 main c solution file PRR L AACA HAA AA AACA HAA AA AA AA AAA AA AAA AAA AA AA Project Orbit Lab 5 ATE int Version 1 0 Date 2 20 2013 Author Brian Zufelt Craig Kief Company COSMIAC UNM Comments This source introduces the concept of interrupts Building on Lab 4 the call to blink the LEDs will execute as soon as BTN 1 is pressed SRA KAA A AACA A A AACA A EEKE kkk Chip type ARM TM4C123GH6PM Program type Firmware Core Clock frequency 80 000000 MHz FEA AAA RACHA AAA AACA HAA AA AA AA HAA AA AA AA HAA AA AA AA AAA AA AA include lt stdbool h gt include lt stdint h gt include inc tm4c123gh6pm h include inc hw_memmap h include inc hw_types h include driverlib gpio h include driverlib pin_map h include driverlib sysctl h include driverlib uart h include inc hw_i2c h include driverlib i2c h include inc hw_ints h include driverlib interrupt h include driverlib timer h Defines not needed to be placed in lab define Lab5_Pro
12. blem define Lab5_ Solution void main void Setting the internal clock lab activity SysCtlClockSet SYSCTL_SYSDIV_5 SYSCTL_USE_PLL SYSCTL_XTAL_16MHZ SYSCTL_OSC_MAIN Enable Peripheral ports for input output SysCtlPeripheralEnable SYSCTL_PERIPH_GPIOC PORTC GPIOPinTypeGPlOOutput GPIO_PORTC_BASE GPIO_PIN_6 GPIO_PIN_7 LED 1 LED 2 SysCtlPeripheralEnable SYSCTL_PERIPH_GPIOB PORTB GPIOPinTypeGPIOOutput GPIO_PORTB_BASE GPIO_PIN_5 LED 4 SysCtlPeripheralEnable SYSCTL_PERIPH_GPIOD PORT D GPIOPinTypeGPIOOutput GPIO_PORTD_BASE GPIO_PIN_6 LED 3 GPIOPinTypeGPIOInput GPIO_PORTD_BASE GPIO_PIN_2 BTN 1 SysCtlPeripheralEnable SYSCTL_PERIPH_GPIOF PORT F GPIOPinTypeGPIOOutput GPIO_PORTF_BASE GPIO PIN _1 GPIO PIN _2 GPIO_PIN_3 RGB LED on Launchpad SysCtlPeripheralEnable SYSCTL_PERIPH_GPIOA PORT A GPIOPinTypeGPIOInput GPIO_PORTA_BASE GPIO_PIN_6 Switch 2 12 lab activity ifdef Lab5 Solution IntEnable INT_GPIOD_TM4C123 GPIOIntEnable GPIO_PORTD_BASE GPIO_PIN_2 GPIOIntTypeSet GPIO_PORTD_BASE GPIO_PIN_2 GPIO_RISING EDGE IntMasterEnable if GPIOPinRead GPIO_PORTA_BASE GPIO_PIN_6 Listen for the switch Removed to run code in complete GPIOPinWrite GPIO_PORTF_BASE GPIO_PIN_1 GPIO_PIN_2 GPIO_PIN_3 4 LED Blue on Launchpad Cycle through the LEDs on the Orbit board GPIOPinWrite GPIO_PORTC_BASE GPIO_PIN_6 GPIO_PIN_7 0x40 LED 1 on LED 2 Off GPIOPinWrite
13. een in Figure 4 the startup_ccs c file has already been integrated into the project This is the nice feature of the installation package that was created for the workshops but that can be also used for future projects with these two boards The starting code should be shown It is also available at the end of the tutorial as Attachment 1 This tutorial starts out where Lab 4 ended As is always the case first in main c is the header files Always use the same nine shown here Secondly it is necessary to enable the ports and then turn on the specific I O pins that will be needed Lab 4 was designed to blink lights and was triggered by and stopped by pushing a button However in Lab 4 the breaks were done without interrupts This means that the only time that the program switches over to blinking lights is when the running routine is complete We start out with the same code as Lab 4 but change the delays to slow it down for visualization This starts out the same as where we ended in Lab 4 but we are going to add the interrupts for Lab 5 Code should be as shown in attachment 1 for a starting point As is always the case click on the bug and then on the green triangle The lights should be blinking slower due to added time in sysctldelay Press and hold button 1 The designer can see how it must finish cycle to escape normal program Do this enough times to be confident that you fully understand when the system breaks away to start blinking lights
14. g software applications A good API makes it easier to develop a program by providing all the building blocks A programmer then puts the blocks together In our case we would refer to them as a set of functions lab activity gt ThisPC gt OS C gt ti gt TivaWare_C_Series 2 1 0 12573 gt docs A Name Date modified Type Size FE SW DK TM4C129X EM CC3000 UG 2 1 0 6 9 2014 2 58 PM Adobe Acrobat D 254 KB F SW DK TM4C129X EM TRF7970ATB UG 6 9 2014 2 58 PM Adobe Acrobat D 246 KB F SW DK TM4C129X UG 2 1 0 12573 pdf 6 9 2014 2 58 PM Adobe Acrobat D 374 KB SW EK LM4F232 UG 2 1 0 12573 pdf 6 9 2014 2 58 PM Adobe Acrobat D 242 KB FE SW EK TM4C123GXL BOOST CAPSENSE 6 9 2014 2 58 PM Adobe Acrobat D 169 KB or FE SW EK TM4C123GXL BOOST CC3000 U 6 9 2014 2 58 PM Adobe Acrobat D 177 KB FE SW EK TM4C123GXL BOOST DLPTRF797 6 9 2014 2 58 PM Adobe Acrobat D 212 KB FE SW EK TM4C123GXL BOOSTXL BATTPA 6 9 2014 2 58 PM Adobe Acrobat D 167 KB FE SW EK TM4C123GXL BOOSTXL BREAKO 6 9 2014 2 58 PM Adobe Acrobat D 171 KB FE SW EK TM4C123GXL BOOSTXL SENSHU 6 9 2014 2 58 PM Adobe Acrobat D 179 KB FE SW EK TM4C123GXL UG 2 1 0 12573 pdf 6 9 2014 2 58 PM Adobe Acrobat D 231 KB FE SW EK TM4C1294XL BOOST CC3000 UG 6 9 2014 2 58 PM Adobe Acrobat D 177 KB FE SW EK TM4C1294XL BOOST DLPTRF797 6 9 2014 2 58 PM Adobe Acrobat D 206 KB FE SW EK TM4C1294XL BOOSTXL BATTPA 6 9 2014 2 58 P
15. he routine Go back up the main c code and delete this unnecessary code that is now accomplished via the ISR For historical purposes it can also be commented out by putting a at the start of the block and a at the end of the block while GPIOPinRead GPIO_PORTD_BASE GPIO_PIN_2 Listen for BTN 1 All LED Blink GPIOPinWrite GPIO_PORTC_BASE GPIO_PIN_6 GPIO_PIN_7 OxFF GPIOPinWrite GPIO_PORTD_BASE GPIO_PIN_6 OxFF GPIOPinWrite GPIO_PORTB_BASE GPIO_PIN_5 0x20 GPIOPinWrite GPIO_PORTF_BASE GPIO_PIN_1 GPIO_PIN_2 GPIO_PIN_3 OxFF White Output SysCtlDelay 2000000 GPIOPinWrite GPIO_PORTC_BASE GPIO_PIN_6 GPIO_PIN_7 0x00 GPIOPinWrite GPIO_PORTD_BASE GPIO_PIN_6 0x00 GPIOPinWrite GPIO_PORTB_BASE GPIO_PIN_5 0x00 GPIOPinWrite GPIO_PORTF_BASE GPIO_PIN_1 GPIO_PIN_2 GPIO_PIN_3 0x00 White Output SysCtlDelay 2000000 lab activity We need to tell the Interrupt Controller were to go to find the ISR Go into the startup_ccs c program Take extreme care when editing this section Errors created in this section will cause an error at boot up and will take a long time to find and correct This first change declares the function for the compiler but doesn t tell it that it is an ISR The fact that ISR is in the function name is for human benefit As shown in Figure 5 type paste in the following code shown below into the startup_ccs c file right below the extern void _c_intOO
16. shops as shown in previous labs Equipment and Materials Access to Tiva TM4C123G LaunchPad software and evaluation kit EK RM4C123GXL It is assumed that the student has already completed Lab 4 and the software is installed properly Itis also assumed that the board is plugged in and the power is applied Software needed Quantity Download Tiva LaunchPad software from the TI website from 1 http www cosmiac org Microcontrollers html Hardware needed Quantity The hardware required is the TI Tiva LaunchPad Kit and the Digilent Orbit 1 board Additional References The Evaluation Board user s manual is on this web site http datasheet octopart com EK TM4C123GXL Texas Instruments datasheet 15542121 pdf and the manuals for the Digilent orbit board are located at http digilentinc com Products Detail cfm NavPath 2 396 1181 amp Prod ORBIT BOOSTER COSMIAC tutorials found at http cosmiac org thrust areas academic programs and design services education and workforce development microcontrollers ate developed material Lab Procedure Install Connect board to computer Plug in the supplied USB cable to the top of the Evaluation Kit and Digilent Orbit board as shown in Figure 2 Ensure the switch on the board is set to DEBUG and not DEVICE It is assumed that the evaluation board is properly installed and operating Launch the Code Composer software lab activity Figure 2 Board Assembly and Attachment
17. tion in the ROM that is called SysCtlDelay To use this function all you do is to call the function and pass in an input integer of how long you want to delay The next important section covered in this lab is the concept of the interrupt Brian always uses the analogy of the automobile airbag deployment system In all the projects we have done prior to this we have always allowed the system to flow from top to bottom This is done to allow for a smooth and predictable flow of the program Unfortunately if you are using this ARM processor in your automobile to control the airbag system and you have an accident you really don t want to wait until the currently running routine finishes You want it to immediately stop what it is doing and activate the airbag NOW This is done via a concept of an interrupt You will be using an Interrupt Service Routine ISR to provide that immediate halting capability lab activity G Grading Criteria N A Time Required Approximately one hour Lab Preparation It is highly recommended that the student read through this procedure once before actually using it as a tutorial By understanding the final goal it will be easier to use this tutorial as a learning guide The other tricky part is related to how your software was loaded While this series of tutorials was being developed a new way to load the software and preload the tutorials was developed Ensure that you used the installer that sets up the work
18. void function call extern void GPIO_PORTD_isr void 19 20 ff RRRRREERAAREE ERE RELEEEREEE LAER K EEE 21 22 External declaration for the reset 23 processor is started 24 1 4 EERAAALALALALALALALALA LALLA LAKH AKE gt fi 26 extern void _c_int void 28 extern void GPIO_PORTD_isr void 9 N Figure 5 Insert ISR Function Call The line of code below defines what is called to in the vector table It defines what code will handle the interrupt Where it is pasted is what is important It is at a specific location in the table GPIO_PORTD _isr GPIO Port D 62 IntDefaultHandler The PendSV handler 63 IntDefaultHandler The SysTick handler 64 IntDefaultHandler GPIO Port A 65 IntDefaultHandler GPIO Port B 66 IntDefaultHandler GPIO Port C 67 PIO PORTD_isr GPIO Port D 68 IntDefaultHandler GPIO Port E 69 IntDefaultHandler UART Rx and Tx Figure 6 ISR Code Copy type the code shown above into the location shown in Figure 6 Take care to place this in the correct location The indentation is shown only for visualization purposes Save all files and click on the bug and green triangle If everything else goes to heck and you find errors you can t resolve don t hesitate to copy all of the main c solution and just paste it into the project lab activity H Immediately when the button one is pressed it jumps to the interrupt The lights immediately begin to blink
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