Need help choosing microcontroller

Except for the A/D converters, the thing could be an Atmel AT91, e.g. AT91R40008. It's based on the ARM7TDMI 32-bit core and contains plenty for your other requirements.

IMHO, external A/D's are much easier to handle because of less digital noise. I'd use any of the SPI converters with the AT91. It's not difficult to bit-bang them on the AT91 I/O ports.

The GNU toolchain (gcc, as, ld, objcopy, gdb ...) supports the chip.

HTH

Tauno Voipio tauno voipio @ iki fi

The philips LPC2106 has 64kB RAM and 128kB FLASH onchip, but no ADC, has I2C and SPI though so you could use an external ADC. ARM core, so gnu compiler available.

The AT91M55800 has internal ADC but needs external memory (128MB max), also ARM core. I think atmel may have closer matching parts, have a look.

Small comparision

AT91M55800: Internal ADC, 8 kB SRAM, 33 MHz AT91M40008: External ADC, 256kB of SRAM, 66 MHz. (60 MIPS when internal operation) AT9RM9200: External ADC, 16 kB SRAM, 16k+16k cache, Burst Flash, SDRAM,

It seems that Atmel ARM processors are the consensus. So, that's what I'll go with. I did a project with a 68332 once. That was also a possibility for me. I really liked that chip.

thanks, William

Then you might also look at the Motorola Coldfire chips, like the MCF8252 and MCF5272.

I'm leaning toward the Atmel AT91R40008. I have a couple of follow-up questions about this.

Does it have a hardware floating point coprocessor? I didn't see that it did, but I haven't yet found full documentation on the processor. Where can I find a full instruction set description?

No. It's a pretty pure RISC without even a divide instruction.

There are documents on the ARM site.

Also, the ARM7TDMI manual is on the Atmel site documentation part.

For complete information, get also the AT91R40008 and AT91X40X data sheets from the same Atmel location.

HTH

Tauno Voipio tauno voipio @ iki fi

So, is there an ARM based processor with integrated floating point? That's what I'm looking for.

thanks, William