1-1 Ramesh Yerraballi EE 319K Introduction to Microcontrollers Lecture 1: Introduction, Embedded Sys, Product Life- Cycle, 9S12 Programming.

1-1Ramesh Yerraballi

EE 319KIntroduction to Microcontrollers

Lecture 1: Introduction, Embedded Sys, Product Life-Cycle, 9S12 Programming

1-2

My Shpeel

“It is important that students bring a certain ragamuffin barefoot irreverence to their studies, they are here not to worship the known but to question it” – Jacob Bronowski

How much do you pay for a Burger?

Per lecture?

Ramesh Yerraballi

1-3Ramesh Yerraballi

Agenda

Course DescriptionBook, Labs, EquipmentGrading CriteriaTAsExpectations/Responsibilities

Embedded SystemsProduct Life Cycle

Analysis, Design, Implementation, Testing Flowcharts, Data-Flow and Call Graphs9S12 Programming

1-4Ramesh Yerraballi

Embedded System

Embedded Systems are everywhere but mostly hidden

MicroProcessor Intel: 4004, ..8080,.. x86 Motorola: 6800, .. 6812,..

PowerPC ARM, DEC,SPARC, Natl

Semi.,… MicroController

Processor+Memory+I/O Ports (Interfaces)

communications

automotive

medical

appliances

consumer electronics

microcomputer

I/O Ports

Microcontroller Electrical,mechanical,

chemical,or

opticaldevices

Embedded system

Bus ADCAnalogsignals

9S12

DAC

Processor

RAM

ROM

I/O Ports

Microcontroller Electrical,mechanical,

chemical,or

opticaldevices

Embedded system

Bus ADCAnalogsignals

9S12

DAC

Processor

RAM

ROM

1-5Ramesh Yerraballi

Microcontroller

MemoryNon-Volatile

oROM oEPROM, EEPROM, Flash

VolatileoRAM (DRAM, SRAM)

InterfacesH/W: PortsS/W: Device DriverParallel, Serial, Analog, Time

1-6Ramesh Yerraballi

Flowchart Example 1.1: Design a flowchart for a system that performs two independent

tasks. The first task is to output a pulse on PTT every 1.024 ms in real time. The second task is to find all the prime numbers, and there are no particular time constraints on when or how fast one finds the prime numbers.

Interrupt triggerClock

Return frominterrupt

void interrupt 7 Clock(void){ PTT = 1; PTT = 0;}

1Connector

main

n = 2

Entry point

Process block

Decision

Function call

1Connector

Prime

Not

Factor(n)

PTT = 1Input/Output

PTT = 0Input/Output

A

B

EF

E

F

<

>

>

Record (n)

n = n+1 DProcess block

C

void main(void){ int n=2; while(1){ if(Factor(n)) Record(n); n = n+1; }}

BCD

A

Function call

1-7Ramesh Yerraballi

Structured Programming

Common Constructs (as Flowcharts)

Block 1

Sequence Conditional While-loop

Block 2Block 1 Block 2 Block

Fork Triggerinterrupt

Join Return from interrupt

1-8Ramesh Yerraballi

Product Life Cycle

Analysis (What?) Requirements ->

Specifications Design (How?)

High-Level: Block Diagrams Engineering: Algorithms,

Data Structures, Interfacing

Implementation(Real) Hardware, Software

Testing (Works?) Validation:Correctness Performance: Efficiency

Maintenance (Improve)

1-9Ramesh Yerraballi

Data Flow Graph

Position Measurement System

1-10Ramesh Yerraballi

Call Flow Graph

Position Measurement System

1-11Ramesh Yerraballi

I/O Ports

Microcontroller Electrical,mechanical,

chemical,or

opticaldevices

Embedded system

Bus ADCAnalogsignals

9S12

DAC

Processor

RAM

ROM

9S12 Assembly Programming

9S12DP5129S12DG128

9S12DP512 Memory Map

Address Size Device Contents

$0000 to $03FF 1024 I/O Ports for Devices Access external devices

$0400 to $07FF 1024 EEPROM: Elec. Erasable Fixed Constants

($2000)$0800 to $3FFF

(8192)

14336

RAM: Random Access Variables and Stack

$4000 to $FFFF 48152 EEPROM: Elec. Erasable Programs and fixed constants

1-12Ramesh Yerraballi

Registers

CC

D

X

Y

SP

PC

8-bit condition code

Two 8-bit accumulators

16-bit index register

16-bit index register

16-bit stack pointer

16-bit program counter

7 0

15X H

Register A Register B

S I N Z V C8

9S12 has 6 registers

1-13Ramesh Yerraballi

9S12 Programming

Simple Program org $3800count rmb 1

org $4000

main ldaa #10 ;loop counter

staa count

loop dec count ; 9,8,… 0

bne loop

stop

org $FFFE

fdb main

Some Basic Instructionsldaa #10 ;make A=10

ldaa $3800 ;A=contents of memory

staa $3800 ;Store contents of A

;into mem

deca ;A=A-1

lsra ;A=A/2 (shift right)

lsla ;A=A*2 (shift left)

adda #10 ;A=A+10

anda #$02 ;A=A&2 (logic and)

eora #$08 ;A=A^8 (exclusive or)

oraa #$03 ;A=A|3 (logic or)

bra loop ;always jump to loop

bne loop ;jump to loop if

; not zero

beq loop ;jump to loop if zero

stop