Processors in Embedded Systems
A Processor in an Embedded Systems contains two essential parts
* Control Unit - Which fetches the instruction from the system memory
* Execution unit
Arithmetic and Logic Unit is also the part of Execution Unit
It performs Data Transfer and data conversion operations
Types of processors
General Purpose Processors (GPP)
Microprocessor
Microcontroller
Digital Signal Processors (DSPs)
Media Processors
useful for sound and image processing applications
Application Specific System Processors
The processors which are relevant to a particular application like
Digital TV
HDTV decoders
Set Top Boxes
DVD Player
Important considerations while selecting a processor
Instruction Set
Maximum bits in an operand like (8 or 16 or 32 bit)
Clock frequency in MHz and processing speed in MIPS (Millions of Instructions per second)
ability to solve the complex algorithms used in meeting the deadline for their processing
Microprocessors
It is a VLSI Chip which has a Central Processing Unit (CPU), which may have some optional components like Cache memory, Floating Point Unit (FPU),etc.
Microcontrollers
Microcontroller contains functional circuits and application specific circuits
Functional Circuits are
Microprocessor
Memory (RAM, ROM, Flash)
Timer (Also Watch Dog Timer)
Interrupt Controller
I/O Ports (Parallel Ports )
UART for Serial Communication.
Application Specific Circuits
LAN Controllers
DMA Controller (Direct Memory Access)
Printer Controller
Analog to Digital Converter (ADC)
Digital to Analog Converter (DAC)
Modem
but now a days, lot of embedded systems comes with ADC, DAC,Modem and DMA Controllers.
Digital Signal Processors
- They are useful in developing applications like Video, audio signal processing,
- Analog signals like ECG, EEG, Seismic Signals, etc are all processed using Digital Signal Processors.
- Most of the DSPs are inbuilt with MAC Units (Multiply and Accumulate Units)
- Texas instruments TM series are some of the example of DSPs
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