Nachiket M' Kharalkar

1
Introduction to Microcontrollers

• Nachiket M. Kharalkar
•  
• Lab 1
• Date 01/31/2008
• E-mail knachike_at_ece.utexas.edu
• http//users.ece.utexas.edu/knachike/spring08/
•  

2

• This presentation
• http//users.ece.utexas.edu/knachike/spring08/
• Lab manual
• http//users.ece.utexas.edu/valvano/EE319K/EE319K
  _Sp2008.pdf

3
TExaS Simulator

• Learn it well, you will use it to take Test 2
• TExaS on all computers in ENS
• Install from blackboard
• Upgrade to latest version http//www.ece.utexas.e
  du/valvano/upgrade.html
• Have Prof Valvano teach you
• http//www.ece.utexas.edu/valvano/Readme.htm

4
(No Transcript)
5
MC9S12DP512 Architecture

• Executes the standard 6812 instruction set
• Port AD0 is an 8-channel 10-bit analog to digital
  converter or Port AD0 is an 8-bit digital input
  port
• Port H is an 8-bit digital bi-directional port
• Port P is an 8-bit digital bi-directional port
• Port T is an 8-bit digital bi-directional port
• Clock runs at 8 MHz

6
Port addresses

• PTH equ 0260 Port H I/O Register
• DDRH equ 0262 Port H Data Direction
  Register
• PTP equ 0258 Port P I/O Register
• DDRP equ 025A Port P Data Direction
  Register
• PTT equ 0240 Port T I/O Register
• DDRT equ 0242 Port T Data Direction
  Register

7
MC9S12DP512 Registers
8
MC9S12DP512 Memory map

• 0x0000-0x03FF I/O ports
• 0x0800-0x3FFF 14K bytes of RAM (Global
  variables are stored from 0800. Stack grows down
  from 3FFF and local variables stored in stack)
• 0x4000-0xFFFF 48K Flash EEPROM simulated in
  TExaS (Total 512K bytes in the chip, Program is
  stored in this region)

9
Texas Simulator
10
Lab 1
PP2
P
AD
T P AD
11
Texas Simulator Loading a program

• Click on the icon on the task bar
  to open Texas simulator.
• Click File ? Open ?
• Open tut.rtf file (from the MC9S12 folder)
• Click Window ? Tile
• Click Mode ? Processor to make sure that the
  processor is MC9S12DP512

12
Texas Simulator Writing your FIRST program

• Click File ? New ? Program ? OK
• File ? New ? Microcomputer ? OK
• File ? New ? I/O device ? OK
• Save each of these 3 windows with the same name
  in the same folder with their respective
  extensions

13
Texas Simulator Writing your FIRST program

• Lab1.RTF
• Program written by Your Name
• Date Created 1/22/2008
• Last Modified 1/22/2008
• Section 1-2pm TA Nachiket Kharalkar
• Lab number 1
• Brief description of the program
• The overall objective of this system is a
  digital lock
• Hardware connections
• PP2 is switch input P
• PAD2 is switch input AD
• PT2 is LED output T (on means unlocked)
• The specific operation of this system
• unlock if AD is not pressed and P is pressed

14

• I/O port definitions on the 9S12DP512
• ATD0DIEN equ 008D ATD Input Enable Mask
  Register
• PORTAD0 equ 008F Port AD I/O Register
• PTT equ 0240 Port T I/O Register
• DDRT equ 0242 Port T Data Direction Register
• PTP equ 0258 Port P I/O Register
• DDRP equ 025A Port P Data Direction
  Register

15

• org 0800 RAM
• Global variables (none required for this lab)
• org 4000 flash EEPROM
• main
• Software performed once at the beginning
• loop
• Software repeated over and over
• bra loop
• org FFFE
• fdb main Starting address

16
Reset Vector

• A reset vector tells the computer where in
  memory to begin execution after reset
• You have to set it up
• For us, program starts at main
• Reset vector of 6812 located at FFFE, therefore
  we had this in our program
• org FFFE
• fdb main

17
Texas Simulator Writing your FIRST program

• Click on the IO window and then click on IO tab.
• Click on LED. Type PT2 for the 1st LED in the
  PORT window, give whatever label name you want.
• Click on the switch tab and enter PAD2 in the
  PORT window similarly enter PP2 for switch P

18
Texas Simulator Writing your FIRST program
Program below the main

• ldaa FF
• staa ATD0DIEN
• movb 00,DDRP
• movb FF,DDRT

19
Texas Simulator Writing your FIRST program

• ldaa PORTAD0
• coma
• anda PTP
• staa PTT

Program inside the loop
20
Texas Simulator Running a program

• Press Crtl B to assemble the program
• Click Green Start button from the toolbar
• Press Red STOP button to stop the program (any
  time)
• Press the Yellow Reset button (or F9) to reset
  the registers etc after stopping.

21
Texas Simulator Debugging

• Now Single step through the program by pressing
  F10
• Create break point by entering address in the
  microcomputer window and press add OR by right
  clicking in the list file window