EMBEDDED PROCESSOR:

For complex real time system normal microprocessor and microcontroller are not suitable. So apecial kind of processor known as embedded processor are required 

The termed embedded processor is perferred instead of microcontroller and microprocessor.

Important embedded processor chips for embedded systems has three streams.

An embedded processor is used when besides fast processing fast context- switching and atomic ALU operation are needed.

DIGITAL SIGNAL PROCESSOR:

Digital signal processor is an essential unit of an embedded system for a large number of applications needing processing of signals.

MEDIA PROCESSOR :

Media processor is a new innovative processor with high system performance for real time video performance , audio processing and data streaming.

It facilitate a seamless fusion of mobile telephony with broadband internet, vioce based web accesses speech recogniton text to speech conversation etc.

APPLICATION SPECIFIC SYSTEM PROCESSOR:

An appliationspecific system processor is used as an additional processing unit for running tw application specific tasks. In place of processing using embedded software

This is used for real time video procesaig. Such as digital television, high definition TV decodes, DVD Players, web phones etc.,

MULTI PROCESSOR SYSTEM USING GPP:

Multiprocessor are used when a signal processor does not meet the need of the different tasks that have to be performed concurrently. It is sychronized to obtain an optimum performance.

For eg., consider a cell phone system the number of task have to be perfomed. They are 

Speech signal compression and coding

Dialing

Modulating and transmitting 

Demodating and receiving 

Signal decoding and decompression

Keypad interface and display interface handling 

Short message service protocol based messaging 

SMS message display

Microprocessor are multi tasking in nature. Can perform multiple tasks at a time.

ROM,RAM,I/O PORTS and timers can be added externally and can vary in numbers.

Designers can decide the number of memory the number of memory or IO ports needed.

System designer should consider the following the processor selection

Instruction set

Maximum bits in an operand in a signal airthemetic or logical operation.

Clock frequency in MHz and processing speed in million instruction per second 

Processor ability to solve the complex algorithms used in meeting the deadlines for their processing.

This process can be understand by considering four respresentative cases.

CASE 1: System in which processor instruction cycle time is qnd on chip devices and memory can suffice.

CASE 2: System in which instruction cycle time is required and high performance needed. Multiport 100mbps network transceiver.