SELECTION OF MICRO-PROCESSOR/SOC FOR CUSTOM EMBEDDED BOARD DESIGNS

10 POINTS TO TAKE CARE WHILE SELECTING THE MICRO-PROCESSOR/SOC for CUSTOM EMBEDDED BOARDS

Micro controller/Microprocessor is like heart of Every Embedded hardware Boards. For Low End boards it might be just a micro controller and for higher platform it will be microprocessors/FPGA. Some of the Examples for micro controllers are : MSP430G2 Series of Texas instruments , Atmega series of Atmel and PiC series of Micro chip.

Freescale, ST, TI, SiLabs, Atmel are the main vendors of high End Micro-processors.choosing the best is one of the toughest decision for an Embedded hardware design engineer.Here in this post i will explain the selection criteria's for choosing a microprocessors/controllers/soc in embedded hardware system.

• Point 1 : Use Dedicate controllers according to Application .

So First selection criteria is based on system application 

ie .if the application is communication there should be required communication interfaces or if it is a video processing/display based applications, support of GPU is also important. 

• Point 2 : Check whether the Microprocessor/SOC supports required Hardware Peripherals.

Hardware peripherals are -GPIO's,SPI,IIC,CAN,USB,ETHERNET,LCD etc. the requirement of hardware peripherals can be obtained by drawing a system level BLOCK diagram. 

• Point 3 : Memory Support

Estimate the memory size required for the application and ensure that it will be supported by the Microprocessor/SOC. it is also important to check the type of memory technology that supports the Microprocessor/SOC . like some Microprocessor/SOC doesn't support DDR memories . 

• Point 4 : CORE Parameters

1. Core Frequency : it is an important factor while choosing Microprocessor/SOC .Clock frequency is the internal clock speed in which the core operates .
2. MIPS : it is the count of instructions in millions executed per second.
   MIPS=count/time *10^6MIPS=Frequency/No of clock *10^6
3. BUS Throughput : Amount of data a processor can process in a certain time . it depends on the bus latency ,Bus width and the bus frequency.
4. Data Bus width : comes in 8 bit / 16 bit and 32 bit . when data bus width increases amount of data processing also increases ie. BuS Throughput increases .
5. Cache size : it is smaller but kind of faster memory in which frequent operated instructions are stored in cache .

• POINT 5 :Power consumption 

Power consumption is an important factor in battery operated applications . there are lot of Microprocessor/SOC with different technologies used to reduce energy consumption. most of the Microprocessor/SOC will have low power modes ,sleep modes etc . PMIC is an advanced power regulator for TI based Microprocessor/SOC.

• POINT 6 : Development & Debugging

 Availability of debugging tools and development IDE is also a main criterion while choosing the Microprocessor/SOC .J links[JTAG] is example for debugging tool for Atmel controllers . XDS 100/200/xx[JTAG] are examples for debugging tools for ti Microprocessor/SOC .

 Development IDE : example TI Code composer studio

J LINK

• POINT 7 : Availability & EOL

 Make sure that the selected processor is available in stock and will not get EOL in near future . 

• POINT 8 : Cost per Unit 

Cost of the Microprocessor/SOC should also be consided while making the selection, especially for large productions. 

• POINT 9 : DESIGN Support

It is the most important criteria while choosing Microprocessor/SOC .because support from manufactures will be required for resolving the issues happening in the development. Manufacture can support by providing reference designs,Technical documents,device drives ,Development boards etc.

Beagle Bone-AM335x development Board

• POINT 10 : Availability of required packages 

Ensure that the required packages are available for the selected Microprocessor/SOC and are in stock.

Thank you for Reading -AJ