RE: Is a 32 bit or 8 bit MCU better for your application Part 2? Processing, Interrupts and Pointers

COMPACT — Fri, 11 Dec 2015 21:32:08 GMT

Sometimes DMA is the way to go to reduce interrupt latencies for particular applications!

"It depends!"

RE: Is a 32 bit or 8 bit MCU better for your application Part 2? Processing, Interrupts and Pointers

michaelkellett — Fri, 16 Oct 2015 08:26:56 GMT

I know Silabs have 8051s to sell but you really are flogging a dead horse.

Most of your 8:32 comparisons here are almost always irrelevant in real applications..

In the real world it's not the size of code on a micro that matters but the cost of the code - and that includes to cost to write it, test it, maintain it, and the cost of the memory on the chip. ARM M0 parts do every well in these areas and tend to offer much more RAM and FLASH for the money than 8051 (or other 8 bit) parts. In low volume (< 1k per year, often more) applications the cost of the chip is way less than the other costs of the code. Writing code for 32 bit parts is much cheaper than for 8051s or PICs.

Your assertions re. interrupt speeds are not convincing - ARM cores offer much more sophisticated interrupt support than 8051s and frequently much faster clocking (it's the time to respond usefully that matters - not the number of cycles). I'd need to see some benchmark evidence to support the "8 bit is faster" claim.

Now why don't Silabs put the nice peripherals from their 8051 range onto a chip with an ARM Mx core and then we would have the best of both worlds.