1. In the lab room CL105, computers are running the operating system Windows 7 Enterprise, and ARM Software Microcontroller Development Kit Version 4.71a (Keil uVision4) is installed. 2. To install it on your home computer, you can download the following file:
~ftp/pub/class/301/ftp/mdk470a.exe 3. To know more about Keil, visit http://www.keil.com/ 4. To know more about the ARM Cortex-M family, visit http://www.arm.com/products/processors/cortex-m/index.php 5. To see STM32VLDISCOVERT board, visit STM32VLDISCOVERY Board. 6. To view Keil uVision4 Tutorials, check the following: Tutorial One Tutorial Two http://www.youtube.com/watch?v=zJncQKNDZv8
To create an assembly language program, you need to use a text editor such as NotePad in Microsoft Windows environment. There is a text edit in the Keil uVision4 for you to use. The file name must have a .s at the end. Let's look at the following program called MyFirstArm.s on a PC. The file MyFirstArm.s contains the source code of the program to load registers and demonstrate a few other operations. We will use Keil uVision4 to create a project and execute this program so that you can get a feel of how Keil uVision4 works.
;The semicolon is used to lead an inline documentation ;This is the first ARM Assembly language program you see in the lab ;This program skeleton is from Dave Duguid and Trevor Douglas in summer 2013. ;When you write your program, you could have your info at the top document block ;For Example: Your Name, Student Number, what the program is for, and what it does etc. ;;; Directives PRESERVE8 THUMB ; Vector Table Mapped to Address 0 at Reset ; Linker requires __Vectors to be exported AREA RESET, DATA, READONLY EXPORT __Vectors __Vectors DCD 0x20001000 ; stack pointer value when stack is empty DCD Reset_Handler ; reset vector ALIGN ; The program ; Linker requires Reset_Handler AREA MYCODE, CODE, READONLY ENTRY EXPORT Reset_Handler Reset_Handler ;;;;;;;;;;User Code Starts from the next line;;;;;;;;;;;; MOV R0, #12 STOP ADD R0, R0, #4 B STOP END ;End of the programReferences:
You can start up uVision4 by clicking on the icon
from the desktop or from the "Start" menu or "All Programs" on a lab PC.
The following screen is what you will see.
Let's create our firt ARM uVision4 project now.
To create a project, click on the "Project" menu from the uVision4 screen
and select "New uVision Project...".
Then, select a folder, give project a name and save.
From the "Select Device for Target" window, select "STMicroelectronics" as the vendor.
click on "+" beside "STMicroelectronics" and then select "STM32F100RB" and click on "OK".
Make sure you click on "NO" for the following pop up window.
Save the program by clicking on the "Save" or "Save As" from the "File" menu and give it a name.
Select "Files of type" as "Asm Source file (*.s*;*.src*;*.a*),
then select the file "FirstARM.s" for example.
Click on "Add", and then click on "Close".
Click on "OK" for the pop up window showing "EVALUATION MODE, Running with Code Size Limit: 32K".
Open your uVision4 to full screen to have a better and complete view.
The left hand side window shows you the registers and the right side
window shows the program code. There are some other windows open.
You may adjust the size of them to see better.
Run the program step by step, you can observe the change of the values in the registers.
Click on the "Start/Stop Debug Session" again to stop executing the program.
We will analyze the program and see how it works.
It works with both the simulated target and the real circuit board STM32VLDISCOVERY Board.
I will demonstrate it in the lab for you.
Here is a diagram of the ARM architecture for your reference.
ARM Architecture is an Enhanced RISC Architecture. It has large uniform Register file and uses Load Store Architecture. i.e. operations operate on registers and not in memory locations. ARM Architecture instructions are of uniform and fixed length. It is a 32 bit processor. It also has 16 bit variant called THUMB. i.e. it can be used as 32 bit and as 16 bit processor.Here is the link with more info.
ARM cores are licensed to partners/manufacturers so as to develop
and fabricate new microcontrollers around same processor cores.
A microcontroller is a small computer on a single integrated circuit
containing a processor core, memory, and programmable input/output peripherals.
The ARM Cortex-M3 microcontroller will be used in the lab with the
For more information, visit STM32VLDISCOVERY Board.
Here is another link to the ARM Archicheture for your reference.
Here is the Register Organization in ARM State.
Here is the Register Organization in THUMB State.
Here is the Program Status Register Format:
In ARM State, there are 16 general purpose registers; one or more status registers are accessible at any one time. In THUMB State, there are 8 general purpose registers; PC, SP, LR and CPSR are accessible. Conditonion code flags in CPSR: N - Negative or less than flag Z - Zero flag C - Carry or bowrrow or extendedflag V - Overflow flagThe links to Register Organization for your reference: reference one | reference two | reference three.
MOV R2, #0x76 ; Move the 8-bit Hex number 76 to the low portion of R2 MOV R2, #0x7654 ; Move the 16-bit Hex number 7654 to the low portion of R2 MOVT R2, #0x7654 ; Move the 16-bit Hex number 7654 to the high portion of R2 MOV32 R2, #0x76543210 ; Move the 32-bit Hex number 76543210 to the R2 LDR R2, = 0x76543210 ; Load R2 with the 32-bit Hex number 76543210 ADD R1, R2, R3 ; R1 = R2 + R3 ADDS R1, R2, R3 ; R1 = R2 + R3, and FLAGs are updated SUB R1, R2, R3 ; R1 = R2 - R3 SUBS R1, R2, R3 ; R1 = R2 - R3, and FLAGs are updated B LABEL ; Branch to LABEL
Thursday, 19-Jan-2017 12:17:09 CST