Applications of PICs Advantages/disadvantages Digital and analogue control Loops, sub-routines, scanning, counting and feedback Interrupts Problems with interfacing to external devices Structure of microprocessors Applications of microprocessors in manufacturing

Programmable Integrated Circuit/Programmable Interface Controller Capable of storing instructions in the form of a programme Can switch output devices on and off in sequence in response to input signals Can be programmed and erased up to 100,000 times Require a supply voltage of 3 to 5.5V Available as 8, 14, 18, 28 and 40 pin DIL packages Applications include alarm systems, medical equipment, vending machines, traffic lights, cash machines, petrol pumps…..

Advantages One PIC can replace a wide variety of separate electronic components or circuits

Advantages One PIC can replace a wide variety of separate electronic components or circuits Increase d product reliability through the use of less components

Advantages One PIC can replace a wide variety of separate electronic components or circuits Increase d product reliability through the use of less components Reduced stock levels

Advantages One PIC can replace a wide variety of separate electronic components or circuits Increase d product reliability through the use of less components Reduced stock levels Simplified product assembly and smaller end products

Advantages One PIC can replace a wide variety of separate electronic components or circuits Increase d product reliability through the use of less components Reduced stock levels Simplified product assembly and smaller end products Greater product flexibility, adaptability resulting in rapid product changes

Advantages One PIC can replace a wide variety of separate electronic components or circuits Increase d product reliability through the use of less components Reduced stock levels Simplified product assembly and smaller end products Greater product flexibility, adaptability resulting in rapid product changes Disadvantages

Advantages One PIC can replace a wide variety of separate electronic components or circuits Increase d product reliability through the use of less components Reduced stock levels Simplified product assembly and smaller end products Greater product flexibility, adaptability resulting in rapid product changes Knowledge of programming required Disadvantages

Advantages One PIC can replace a wide variety of separate electronic components or circuits Increase d product reliability through the use of less components Reduced stock levels Simplified product assembly and smaller end products Greater product flexibility, adaptability resulting in rapid product changes Knowledge of programming required PICs have a low power output and so require interfacing circuitry to drive higher current devices Disadvantages

System diagrams can still be used to develop designs, but the process element would be replaced with lines of programme rather than a list of components INPUTPROCESSOUTPUT INPUT PIC MICROCONTROLLER OUTPUT For traditional electronics this would require a variety of components designed through a circuit diagram Although still requiring a circuit, processing would be programmed with all previous components being replaced by a single PIC

Like all computers, a PIC micro controller has a Central Processing Unit, Random Access Memory, Read Only Memory, a clock and Input/Output ports. The key difference is that all of these are built into one IC, rather than a variety of individual ICs CPU IO RAM ROM

FLASH Most common form Can be erased up to 100,000 times Reprogrammed by simply downloading the new programme to the IC Offer flexibility to manufactures Can be programmed only once More suited to mass produced products One Time Programmable (OTP)

Process Decision Input/Output Terminator Subroutine Programming can be via a flow chart sequence or BASIC programming language

Intel Museum - How Microprocessors Work #1 How Do Microprocessors Work??