Microcontroller Freescale or ST

[ahmetuyanik]

Dear All,

I need your help who has an experience with ST or Freescale microcontrollers. I have to choose a microcontroller for a new project. I have been searching for two weeks but I have not decided yet. The requirements and the constraints as follows:

Requirements:
1-   Min 128kB SRAM (internal)
2-   Min 32 kB Flash
3-   Min 3 x High Speed SPI
4-   DMA which can access SPI ports.
5-   Min 1 UART
6-   20 GPIOs
7-   Min 100MHz Clock speed.
8-   FPU (Floating Point Unit)

Constraints:
1-   Short development time
2-   Chip and available in the market.
3-   Small size

The microcontroller will collect data from SPI bus and store some time and send another microcontroller from another SPI bus without CPU interaction. CPU will do some analysis with the data and control a system using GPIOs.

Considering requirements I found 2 microcontroller. One from ST and one from Freescale. I am familiar with Microchip, Texas and Cypress but I have not used ST or Freescale microcontroller before.

These two microcontroller series met the requirements.

1-   STM32F4 series from ST
2-   Kinetic- K10_120 from Freescale

STM32F4 has an Arm-core and a FPU which runs at 168MHz. K10_120 has an Arm-core, DSP and FPU which runs at 120MHz.

After brief explanation I would like to know that:

1-   I have faced some bugs and I do not want to consume valuable time to find and try to fix. STM and K10 are stable right now.
2-   I have 2 months to finish unit which contains microcontroller. So I have to learn the structure and how to program less than 2 months. I think STM32 is simpler than K10 and I need which is simple. What is your idea?
3-   I also need user friendly development platform, IDE and C compiler for free.
4-   I will buy development kit at the beginning. I checked on Farnell STM series is more chipper. However I could not understand why it is so chip. Is it bad product or It is new and ST intentional sell like that.

I am waiting your valuable comment from who has an experience with one of chosen microcontroller. I would be happy to know if you have a better suggest.

Best Regards,

[vantusaonho]

I think you should choose STM32, and mikroC from mikroelektronika to program it. It is easy!

[Gallymimu]

An important piece of information...

What is the incoming and outgoing SPI bus speed you are dealing with?  What is the data rate (which will tell us the duty cycle of the SPI.  How large of a data buffer do you need (Do you need all 128MB of processor memory)

This is far more important than many of the other requirements you listed.

We can be much more helpful if you give the system specs rather than processor specs (which might not really be what you need to get the job done)

[ahmetuyanik]

Dear Gallymimu and Vantusaonho

Thank you for your reply.

SPI bus speed will be around 20 MHz. Data buffer is needed exactly 96 kByte for storage and I need 4 or 5 kByte for other variables. So I need more than 101 kByte SRAM and considering the futher requirements I am searching a microcontroller whose sram capacity is at least 128kByte.

The specs. has been decided based on technical needs and experience. The given specs. are needed for sure.

Thank you again for kind reply

Best Regards,

[Gallymimu]

Thanks for the extra info.

Lot's of people post needs without REALLY knowing what they actually need.  People try to help and then find out they were going in the wrong direction with advice because the OP was asking for the wrong stuff!

I'm more of a PIC guy so I can't offer any input other than considering a CPLD, but I don't think that would make sense if you have any modest amount of processing of the data.

[ahmetuyanik]

Dear all

The subject should be closed. I have decided to use STM32F4. K10_120 is more complex for my application and also STM32F4 is chepear than K10-120. Freescale has own IDE called Codewarrior. It is free upto 128kB flash size. Although ST has not own IDE, many IDEs support STM32F4 like IAR, Keil, Coocox,CrossWorks, Atolic, Raisonance, etc. This IDEs are generally free upto 32kB flash size. My application won't exceed 32kB so there is no problem. I am not sure but Coocox and Atolic may be unlimited. I will get STM32F4 Discovery Kit and ST-Link/V2 as in circuit debugger/programmer and download Keil free version. If I need two core I will consider K10-120.

Best Regards,