MICROCONTROLLERS. What is a microcontroller? A microcontroller is a nifty little gadget that houses...

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MICROCONTROLLERS

Transcript of MICROCONTROLLERS. What is a microcontroller? A microcontroller is a nifty little gadget that houses...

Page 1: MICROCONTROLLERS. What is a microcontroller? A microcontroller is a nifty little gadget that houses a microprocessor, ROM (Read Only Memory), RAM (Random.

MICROCONTROLLERS

Page 2: MICROCONTROLLERS. What is a microcontroller? A microcontroller is a nifty little gadget that houses a microprocessor, ROM (Read Only Memory), RAM (Random.

What is a microcontroller? A microcontroller is a nifty little gadget

that houses a microprocessor, ROM (Read Only Memory), RAM (Random Access Memory), I/O (Input Output functions), and various other specialized circuits all in one package.

Page 3: MICROCONTROLLERS. What is a microcontroller? A microcontroller is a nifty little gadget that houses a microprocessor, ROM (Read Only Memory), RAM (Random.

Zilog Z-80

Page 4: MICROCONTROLLERS. What is a microcontroller? A microcontroller is a nifty little gadget that houses a microprocessor, ROM (Read Only Memory), RAM (Random.

What is the Z-80 family of components? significant advancement in the state-of-the-art of microcomputers. It

can be configured with any type of standard semiconductor memory to generate computer systems with an extremely wide range of capabilities. With additional memory and I/O devices a computer can be constructed with capabilities that only a minicomputer could previously deliver.

Advantages… fully software compatible with the popular 8080A CPU superior in both software and hardware capabilities (less cost and

more features) offers the user significant speed advantages (up to 16 MHz clock

rate) including full software support

Page 5: MICROCONTROLLERS. What is a microcontroller? A microcontroller is a nifty little gadget that houses a microprocessor, ROM (Read Only Memory), RAM (Random.

Z-80 CPU Z80 microprocessor is an 8 bit CPU with a

16 bit address bus capable of direct access of 64k of memory space. It has a language of 252 root instructions and with the reserved 4 bytes as prefixes, accesses an additional 308 instructions. The Z80 was modeled after the 8080 and contains the 78 - 8080 opcodes as a subset to it's language.

Page 6: MICROCONTROLLERS. What is a microcontroller? A microcontroller is a nifty little gadget that houses a microprocessor, ROM (Read Only Memory), RAM (Random.

Programming features include an accumulator and six eight bit registers that can be paired as 3-16 bit registers. In addition to the general registers, a stack-pointer, program-counter, and two index (memory pointers) registers are provided. While not in the same league as the 80486 or 68000 series, the Z80 is extremely useful for low cost control applications. One of the more useful features of the Z80 is the built-in refresh circuitry for ease of design with DRAMs.

Page 7: MICROCONTROLLERS. What is a microcontroller? A microcontroller is a nifty little gadget that houses a microprocessor, ROM (Read Only Memory), RAM (Random.

It comes in a 40 pin DIP package. And recently also in a 44 pin SMD and QFP. It has been manufactured in A, B, and C models, differing only in maximum clock speed. It also has been manufactured as a stand-alone microcontroller with various configurations of on-chip RAM and EPROM.

Page 8: MICROCONTROLLERS. What is a microcontroller? A microcontroller is a nifty little gadget that houses a microprocessor, ROM (Read Only Memory), RAM (Random.

Peripheral Interface Controller (PIC)

Page 9: MICROCONTROLLERS. What is a microcontroller? A microcontroller is a nifty little gadget that houses a microprocessor, ROM (Read Only Memory), RAM (Random.

What is a PIC? PIC stands for Peripheral Interface

Controller, which is Microchip, Inc.'s trademark for their line of 8-16 bit microcontrollers. Actually, Microchip's official name for the lineup is PICMicro.

Page 10: MICROCONTROLLERS. What is a microcontroller? A microcontroller is a nifty little gadget that houses a microprocessor, ROM (Read Only Memory), RAM (Random.

More about PICs… Various models are available with different

peripherals built in such as; multiple timers, A/D conversion, serial interfacing, LCD control, etc. They are also available in SMT packaging or standard DIP packaging with as many as 68 pins or as few as 8 pins. Some of the latest versions (and many future versions) have flash memory, making for simple erasures and reuse. Most of the current versions employ EPROM which requires erasure with a special UV lamp.

Page 11: MICROCONTROLLERS. What is a microcontroller? A microcontroller is a nifty little gadget that houses a microprocessor, ROM (Read Only Memory), RAM (Random.

If you want to develop firmware for a PIC, you will need an erasable version. The erasable types available are of the EPROM, EEPROM, and flash memory varieties. EEPROM and flash memory devices are great because they don't need that UV eraser and are less expensive. Unfortunately the flash and EEPROM (EEPROM is being phased out in favor of flash) versions are not available in all configurations, but it seems Microchip is expanding their horizons. One of the most popular versions of the PIC for beginners is the PIC16F84. It uses flash memory (hence the F in its part number), and has 18 pins. Thirteen of these pins can be used for input or output purposes.

Page 12: MICROCONTROLLERS. What is a microcontroller? A microcontroller is a nifty little gadget that houses a microprocessor, ROM (Read Only Memory), RAM (Random.

What can one use a PIC for? PICs are very versatile and can be used in

practical projects such as burglar alarms, caller ID boxes, remote controls, clocks, and just about anything you can think of that could use a single chip self contained computer.

Page 13: MICROCONTROLLERS. What is a microcontroller? A microcontroller is a nifty little gadget that houses a microprocessor, ROM (Read Only Memory), RAM (Random.

Why choose PICs? Because getting into them wasn't a big

investment They have a lot of bang for the buck. There are only about 35 simple RISC-type (Reduced Instruction Set Computer) commands to learn. There is a lot of help available for beginners.

Page 14: MICROCONTROLLERS. What is a microcontroller? A microcontroller is a nifty little gadget that houses a microprocessor, ROM (Read Only Memory), RAM (Random.

Developing the PIC…

First choose the PIC. Learn a language. Choose the

programmer. Wire the circuit on the

target board. Write the code. Program.

Page 15: MICROCONTROLLERS. What is a microcontroller? A microcontroller is a nifty little gadget that houses a microprocessor, ROM (Read Only Memory), RAM (Random.

Sample Program: Blinking Lights list p=16f84 porta equ 0x05 portb equ 0x06

org 0x000

start movlw 0x00 tris porta movlw 0x00 tris portb clrf porta clrf portb

hi bsf porta, 0 bcf porta, 0 goto hi

end

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