Could use some uC suggestions.....

[jp128k]

Hi,

I'm hoping somebody can give me some suggestions on a uC for a project I am doing. I need to sample 2 signals simultaneously at 1MSPS. Ideally I would like a part with at least 128k RAM so I don't have to buffer data external. If I do, then the uC will need to have 2 SPI ports @ 20MHz. Could use some suggestions on parts. I'm getting tired of reading datasheets.

Thanks,
jp

 

[bigdogguru]

The required moderately high sample rate (1MSPS) narrows the field of possibilities.

What MCU architectures are you familiar?

You have not specified a required ADC resolution or whether the ADCs are single or differential ended.

Why the need for two 20MHz SPI ports? For external ADCs?



If this is the case and built-in ADCs would alleviate the need for multiple high speed SPI ports, one possible option is the SiLabs Analog Intensive 8051 series:

**broken link removed**

Silicon Labs C8051F06X Datasheet

These series of MCUs offer two independent 16-bit ADCs capable of a maximum 1MSPS rate, along with dedicated DMA channel to both internal and external storage.

Of course this option would require the implementation of external storage, however doing so is quite straight forward.

Silabs also offers development boards and kits, complete with a USB JTAG programmer/debugger, at reasonable prices.


Another option would be to use an ARM, like the following:



Silicon Labs SiM3C1xx Datasheet

Which offer two independent ADCs capable of 1MSPS in 10-bit mode, multichannel DMA, up to 3 SPI ports @10MHz and 32kB of SRAM, expandable to 16MB externally.


Another option would be the use of a TI C2000 - Piccolo, Delfino or Concerto Series MCU.

TI 32 bit Real-time C2000™ Microcontrollers

**broken link removed**




There are other possibilities, although I'll wait for feedback on these recommendations and the few questions at the beginning of my reply.

BigDog

 

[jp128k]

The required moderately high sample rate (1MSPS) narrows the field of possibilities.

You have not specified a required ADC resolution or whether the ADCs are single or differential ended.

Why the need for two 20MHz SPI ports? For external ADCs?

If this is the case and built-in ADCs would alleviate the need for multiple high speed SPI ports, one possible option is the SiLabs Analog Intensive 8051 series:

**broken link removed**

Silicon Labs C8051F06X Datasheet

These series of MCUs offer two independent 16-bit ADCs capable of a maximum 1MSPS rate, along with dedicated DMA channel to both internal and external storage.

Of course this option would require the implementation of external storage, however doing so is quite straight forward.


Another option would be to use an ARM, like the following:



Silicon Labs SiM3C1xx Datasheet

Which offer two independent ADCs capable of 1MSPS in 10-bit mode, multichannel DMA, up to 3 SPI ports @10MHz and 32k byes of SRAM expandable to 16MB externally.

There are other possibilities, although I'll wait for feedback on these recommendations and the few questions at the beginning of my reply.

BigDog

I prefer 12-bit resolution but 10-bit will work too. The need for the SPI port is for external RAM if there is not enough internal ram to buffer data. I need at least 128k of internal RAM to avoid using external RAM.

jp

 

[bigdogguru]

I prefer 12-bit resolution but 10-bit will work too. The need for the SPI port is for external RAM if there is not enough internal ram to buffer data. I need at least 128k of internal RAM to avoid using external RAM.

If the SPI ports were required for external storage, then all the posted options would fulfill your requirements as an SPI port is not required to increase the available SRAM in these cases.

Including the third option I've added, the TI C2000 series of MCUs, they offer devices which could easily exceed your specs.


Which MCU architecture are you most comfortable? Which MCU architecture do you already have development tools?

These questions should narrow the field a bit.

BigDog