1. Lecture 7: Overview Microprocessors / microcontrollers.
Device architectures
Software development
High level languages
The EXAM

2. Microcontrollers / Microprocessors
Computer on a chip IO memory often application specific
Cheap often used in embedded systems.
Microprocessor
CPU ALU registers.
Needs external memory.
Example use: personal computers.

3. Components of a Microprocessor (or CPU in a PIC)

4. Some components of a microprocessor.
Buses -
Address: Carries memory address
Data: Caries data from and to memory
Control: Signals used to sequence operations
Control Unit- Generates control sequences based on Instruction Register
Arithmetic Logic Unit: Does the sums!
Registers:
General purpose (store numbers)
Program Counter (address of next instruction)
Status Register (flags like carry bit/zero etc)
Instruction Register (instruction being executed)

5. Architecture / buses
How components are connected.

6. Types Architecture.
Von Neumann
Harvard
Cellular?

7. Von Neumann (most microprocessors)
Single memory for DATA and PROGRAM
Shared bus (Von Neumann bottle neck)

8. Harvard (microcontrollers / DSP chips)
Separate memory for DATA and PROGRAM
Different buses (may different widths)

10. Software development for the PIC.
Specify requirements.
Write assembly code using an editor.
Compile into machine code (assembler) .
Fix compile time errors
Program the pic (e.g. PICKit3)
Fix run time errors ( go back to step 2.)
It Works!

11. Incremental / Evolutionary Development
Large complex systems are difficult to write/debug
Start with a simple system and add complexity.
Use routines to “encapsulate” functionality and allow easy reuse of code.

12. Integrated Development Environment IDE
A program that manages the development process .e.g. MPLABx
Automates the process (hides some of the details!)

13. Other Microchip devices

14. Typical Features. GPIO (general purpose IO pins) Interfaces:
SPI I2C UART Ethernet USB
PWM generators (motor control)
ADC (less common DAC)
Signal processing
Timers
More interrupts

15. Other manufacturers Texas Instruments Atmel e.g. MSP430
have similar hardware / software.
Texas Instruments
e.g. MSP430
Atmel
AVR general purpose
ARM (Linux android MS windows)

16. RISC (Reduced Instruction Set Computers)
RISC is a common type of instruction set.
Examples:
ARM (Advanced RISC Machine)
Widely used 32bit instruction set
MIPS Microprocessor without Interlocked Pipeline Stages
(e.g. Play-station)

17. High level languages Different devices have different: Architectures
Instruction sets
A compiler can translates a high level languages program (C C ) into machine code for the target device

18. Arduino
. . is an open-source electronics prototyping platform based on flexible, easy-to-use hardware and software. It's intended for artists, designers, hobbyists, and anyone interested in creating interactive objects or environments.
Various boards (different manufacturers)
Open source IDE (Linux, Windows, mac OS X)
High level C++ based programming language.
Libraries to help you do things !!!!

19. Showing how easy it is to write to the LCD display!
Arduino IDE
Showing how easy it is to write to the LCD display!

20. Applications of microcontrollers
Automotive
Home entertainment
Industrial Automation
Metering
PC Peripherals
Etc

21. Summary Students should understand:
Assembly code and it's relationship with machine code.
Understand the components of the PIC and microprocessors
The different architectures and there merits.
How to program in assembly code for the PIC16F84.
How to interface to SPI devices.
How to interface to parallel devices ( LCD display).

22. Exam 1 Hour 2 sections each with 2 questions PJL / CTC.
Answer 2 questions, one from each section.
Instruction set from PIC16F84 will be provided.
See:
PIC16F84A_EXAM_SUMMARY.pdf