MCU – Microcontroller Unit – 1 MCU  1 cip or VLSI core – application-specific

Embedded system: is a system whose principal function is not computational, but which is controlled by a computer embedded within it.

Examples: Refrigerator

Examples: Car Door

Examples: Derbot Autonomous Guided Vehicle

The microprocessor is a processor on one silicon chip. The microcontrollers are used in embedded computing. The microcontroller is a microprocessor with added circuitry.

Microcontrollers

Microcontroller Packaging and Appearance Some slides above are from - Dr. Gheith Abandah From left to right: PIC 12F508, PIC 16F84A, PIC 16C72, Motorola 68HC05B16, PIC 16F877, Motorola 68000

Types of MCU – 8/16/32-bit mcu – internal bus & instruction size, ALU – Instruction sets – RISC/CISC Complicated instruction set comp [CISC] – It has an instruction set that supports many addressing modes. – It offers flexibility in choosing various ways of performing the data transfer and ALU ops. Reduced ISC [RISC] – Supports 1/2 addressing modes – Need many registers – so need less fetching from external memories for operations… so higher performance in computing than CISC… e.g., ARM

Types of MCU – Memory architecture Harvard mem  has a distinct mem address space for i.Program mem & ii.Data mem  It has separate instructions,  hence separate control signal[s], for data transfers from these two memories. Princeton mem  has a common mem space for both. So no need for separate …

Types of MCU – Family 8051 – Intel – Philips – Atmel – Siemens – Dallas Motorola PIC - Peripheral Interface Controller Hitachi Texas ARM - Advanced RISC Machine (previously known as Acorn RISC Machine) Others

Selection of MCU Checklist – 8/16/32 bit ALU – Max. power dissipation – Clock speed needed – Instructions set  RISC/CISC

Selection of MCU… Checklist – – Memory architecture – Memory size – Cache, memory management unit, DSP calculations – Internal PROM/… – I/O ports – Cost

Selection of MCU… Additional checklists – Cost when single chip and when MCU interfaces to circuit with some features – Major building blocks of hardware cost and availability – Major building blocks of software cost and availability – Ease of integration – Design team expertise – Manpower

Applications Numerous! e.g., Biomedical instruments Communication systems Controller Instrumentations Control systems Automotive apps, etc.

Program mem – mainly Volatile / ROM Data mem - non-volatile mem / RAM

Intel 8051/8031 architecture CPU has the control and sequencing logic circuits, ALU, Flags, clock Program mem - ROM Interrupt control ckt Internal timing devices – timer Serial interface Data mem - RAM

Intel 8051/8031… Special function registers Ports Register banks – 4 set of registers RST – reset pin INT – interrupt pins VCC – voltage supply pin GND