ARM Cortex M course

1. 
   
2. 
   
3. 
   

4.  From Assembler to RTOS

If you are interested in the online course please write to the email below:
(Si estas interesado en el curso en linea contactanos al correo de abajo). 
postgraduatecahg@gmail.com 
Dr. Carlos Hernadez.


Syllabus 2018

1. Introduction.

2. Architecture.

  a. Registers.

  b. Instruction set.
3. Introduction to keil Uvision

4. I/O Configuration.

a. PORT F.

b. PORT A.

c. PORT B.

6. PLL.

7. Serial communication RS-232.

8. ADC.

9. SPI and DAC.

10. TIMERS.

11. Interrupts.

11. TIMER interrupt.

12. Introduction to RTOS.

PORTB & Seven Segment Display

Thus the PORTB.0 is going to be a
PORTB.1 is the b terminal and so on.

Display	a	b	c	d	e	f	g
0	1	1	1	1	1	1	0
1	0	1	1	0	0	0	0
2	1	1	0	1	1	0	1
3	1	1	1	1	0	0	1
4	0	1	1	0	0	1	1
5	1	0	1	1	0	1	1
6	1	0	1	1	1	1	1
7	1	1	1	0	0	0	0
8	1	1	1	1	1	1	1
9	1	1	1	1	0	1	1

--------------------------------------------------------------------------------------------------------------------------


#include "TM4C123.h"                    // Device header

// begins the definition of the registers of Port B to be used as a GPIO
#define SYSCTL_RCGC2_R     (*((volatile unsigned long *)0x400FE108))
#define GPIO_PORTB_PCTL_R  (*((volatile unsigned long *)0x4000552C))
#define GPIO_PORTB_AMSEL_R (*((volatile unsigned long *)0x40005528))
#define GPIO_PORTB_DIR_R   (*((volatile unsigned long *)0x40005400))
#define GPIO_PORTB_AFSEL_R (*((volatile unsigned long *)0x40005420))
#define GPIO_PORTB_DEN_R   (*((volatile unsigned long *)0x4000551C))
#define GPIO_PORTB_DATA_R  (*((volatile unsigned long *)0x400053FC))
// ends the definition of the registers of Port B

// begins the definition of the registers of Port F to be used as a GPIO
#define GPIO_PORTF_DATA_R       (*((volatile unsigned long *)0x400253FC))
#define GPIO_PORTF_DIR_R        (*((volatile unsigned long *)0x40025400))
#define GPIO_PORTF_AFSEL_R      (*((volatile unsigned long *)0x40025420))
#define GPIO_PORTF_PUR_R        (*((volatile unsigned long *)0x40025510))
#define GPIO_PORTF_DEN_R        (*((volatile unsigned long *)0x4002551C))
#define GPIO_PORTF_LOCK_R       (*((volatile unsigned long *)0x40025520))
#define GPIO_PORTF_CR_R         (*((volatile unsigned long *)0x40025524))
#define GPIO_PORTF_AMSEL_R      (*((volatile unsigned long *)0x40025528))
#define GPIO_PORTF_PCTL_R       (*((volatile unsigned long *)0x4002552C))
#define SYSCTL_RCGC2_R          (*((volatile unsigned long *)0x400FE108))
// ends the definition of the registers of Port F


int i=0;

void PortB_Init(void);
void delay(unsigned long halfsecs);

int main()
{
char x [] = {0x3F, 0x06, 0x5B, 0x4F, 0x66, 0x6D, 0x7D, 0x07, 0x7F, 0x6F};

PortB_Init();

while(1)
{

for(i = 0; i < 10; i++)
{
GPIO_PORTB_DATA_R |= x[i];
delay(5);
GPIO_PORTB_DATA_R &= 0x00;
}

}
}


void PortB_Init(void){
volatile unsigned long delay;
SYSCTL_RCGC2_R |= 0x00000002; //1) activate clock for Port B
delay = SYSCTL_RCGC2_R; //allow time for clock to start
GPIO_PORTB_AMSEL_R &= ~0xFF; // 3) disable analog on PA5
GPIO_PORTB_PCTL_R &= ~0xFFFFFFFF; // 4) PCTL GPIO on PA5
GPIO_PORTB_DIR_R |= 0xFF; // 5) direction PortB output
GPIO_PORTB_AFSEL_R &= ~0xFF; // 6) PB regular port function
GPIO_PORTB_DEN_R |= 0xFF; // 7) enable the PB as a digital port
}

void delay(unsigned long halfsecs){
  unsigned long count;

  while(halfsecs > 0 ) { // repeat while there are still halfsecs to delay
    count = 1538460; // 400000*0.5/0.13 that it takes 0.13 sec to count down to zero
    while (count > 0) {
      count--;
    } // This while loop takes approximately 3 cycles
    halfsecs--;
  }
}

Write a program to add ten numbers from 0 to 10 or Convert following C language to ARM assembly Language.

void main()

{

int sum;

int i;

sum =0;

  for (i=0;i <10;i++)

  {

  sum = sum +1;

  }

}

--------------------------------------------

AREA myData, DATA

COUNT EQU 10  ; we will test count upto 10

SUM   EQU 0 

  AREA MYCODE, CODE

  ENTRY

  EXPORT __main

__main

  LDR r0,=COUNT

  LDR r1, =SUM

  LDR r2, =1  ;r2 stores the initial vale of i Myloop

myloop

  ADD r1, r2, r1  ;sum = i + sum

  SUBS r3, r0, r2 ; r3 = r0-r2 (check if r0 and r2 are equal)

  BEQ stop  ;Branch to stop label if r0-r2=0, Z=1

  ADD r2, r2, #1  ; increment i

  BNE myloop  ; if flag not set then do the loop again

stop 

  B stop

  END

Convert the following C code to ASM for the ARM Cortex M4
-------------------------------------

void main ()

{

if (R1 ==R2)

  {

  R3 = R4 - R5;

  }

else if (R1>R2)

  {

  R3 =R4 + R5;

}

}

__main

  MOV r1,#2

  MOV r2,#1

  MOV r3,#1

  MOV r4,#1

  MOV r5,#1

COM

  CMP R1, R2    ;R1-R2 and set the flag

  SUBEQ R3, R4, R5  ; SUB if R1 = R2 it means that Z flag is 1

  ADDGT R3, R4, R5  ; ADD if R1 > R2 it means that C flag is 1

  B COM  ;JUMP to COM address

  END

MOVW and MOVT

Dr. C. A. Hernandez-Gutierrez

--------------------------------------------

if you want to load a 32 bits value you should to write MOVW followed by MOVT. Where MOVT is move TOP.

MOVW writes the less significant 16 bits of a register.

for example :

MOVW R0, #0xAAAA

it means that R0 = 0x0000AAAA

MOVT means MOV TOP 

for example:

MOVT R0, 0xFFFF

it means that R0 = FFFF0000

Finally, we share an example:

--------------------------------------------

main

  MOV R3,#0

  MOVW R3, #0xABCD  ;MOV Wide

  MOVT R3, #0xFFFF  ;MOV TOP

  B main  ;JUMP to main address

  END

--------------------------------------------

After the program finish R3 is going to be:

R3 = 0xFFFFABCD

--------------------------------------------

Convert the following C code to ASM for the ARM Cortex M4

-------------------------------------------------------------------

if (R0 ==R1)

  {

  R2 = R3 + R4;

  }

--------------------------------------------------------------------

AREA MYCODE, CODE

  ENTRY

  EXPORT __main

 

__main

  MOV r0,#1

  MOV r1,#1

  MOV r2,#5

  MOV r3,#5

  MOV r4,#1

COMPARATION

  CMP r0, r1

  ADDEQ r2, r3, r4

  B COM

  END

First program in assembler using Keil and ARM Cortex M4

(It is important to say that it is compatible with  Cortex M3)

Description: In general, this program moves immediate data to registers R0 and R1 and subsequently adds them.

The idea is that you can easily copy the code in Keil and do the respective debugging.

Any question please let me know.

If you want help with a project, a course or consultancy please contact me.

--------------------------------------------------------------------------------------------------------------------------

AREA MYCODE, CODE

  ENTRY

  EXPORT main

main

  MOV r0, #11

  MOV r1, #1

  ADD r2, r1, r0

  B main

  END
--------------------------------------------------------------------------------------------------------------------------

AREA

The AREA directive instructs the assembler to assemble a new code or data section. Sections are independent, named, indivisible chunks of code or data that are manipulated by the linker.

Syntax

AREA sectionname{,attr}{,attr}...

AREA Example,CODE, READONLY; An example code section. ; code

ENTRY

The ENTRY directive declares an entry point to a program.

Syntax

ENTRY

Usage

You must specify at least one ENTRY point for a program. If no ENTRY exists, a warning is generated at link time.

You must not use more than one ENTRY directive in a single source file. Not every source file has to have an ENTRY directive. If more than one ENTRY exists in a single source file, an error message is generated at assembly time.

Example

AREA ARMex, CODE, READONLY

ENTRY ; Entry point for the application

http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0489e/Chdibhie.html

http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0489e/Chdibhie.html