topic Re: Finding the right processor in ColdFire/68K Microcontrollers and Processors

Finding the right processor

Jamo — Fri, 23 Jul 2010 13:04:07 GMT

Hi,

I am still fairly new at hardware design. I have been browsing through the freescale range and getting a bit overwhelmed.

Basically I am looking for the right processor to perform the following basic functions:

Specs

## Dual Ethernet (10/100 is fine) - Looking for somehting that can send a packet between ethernet ports at a speed of at least 1Mbps.

## 2 x Serial Ports

## 1 x port to talk to an SD card

## at least 20 General Purpose IO (GPIO). Need to drive around 12LEDS

## Sufficient processing power to perform a specific function. This processing function is to receive a JPG image of around 50KB from one ethernet port, shrink the image to 5KB and send it quicky out the other ethernet port.

## Capacity to add some memory

## Packaging to not be BGA (as manufacturing is more expensive)

## Pricing range for processor is $40USD

I have plenty of room on the PCB so there is not a space issue

Power is not an issue either

I would be open to a processor at a different price bracket if there were solid benefits.

My other questions are:

How can I tell how fast the ethernet ports can work?

Is it dependant on the processor speed of the micro?

If anyone can steer me in the right direction, it would be much appreciated

Jamo

Re: Finding the right processor

scifi — Fri, 23 Jul 2010 18:12:03 GMT

Hi Jamo,

I think the requirement to have two Ethernet interfaces and a QFP package will limit your search very quickly. Try searching "dual ethernet" on this site. One of the top results is MCF5301x:

MCF5301x

And I wouldn't worry about the speed of Ethernet ports. 1 Mbps is very slow, you will struggle to find an MCU that cannot support this.

Regards,

- mike

Re: Finding the right processor

Jamo — Tue, 27 Jul 2010 06:01:27 GMT

Thanks for that scifi,

In regards to the limitations to choice if I do not BGA, is the overall direction of higher end 32bit processors going to be BGA?

I did speak to the manufacturer and they indicated a preference towards traditional as the costs are higher and debugging is more difficult.

Does using BGA force the design board to use more than 2 layer? Or is 2 layer design still possible?

How would you diagnose problems on a BGA design if all the pins are hidden?

My learing curve is steep for sure..

Jamo