View Single Post
  #44   Spotlight this post!  
Unread 05-05-2012, 15:26
EricVanWyk EricVanWyk is offline
Registered User
no team
 
Join Date: Jan 2007
Rookie Year: 2000
Location: Boston
Posts: 1,597
EricVanWyk has a reputation beyond reputeEricVanWyk has a reputation beyond reputeEricVanWyk has a reputation beyond reputeEricVanWyk has a reputation beyond reputeEricVanWyk has a reputation beyond reputeEricVanWyk has a reputation beyond reputeEricVanWyk has a reputation beyond reputeEricVanWyk has a reputation beyond reputeEricVanWyk has a reputation beyond reputeEricVanWyk has a reputation beyond reputeEricVanWyk has a reputation beyond repute
Send a message via AIM to EricVanWyk
Re: Non-FRC Motor Controller?

Quote:
Originally Posted by rbmj View Post
The microcontroller's timer interrupts must be highly optimized then... at full frequency on a PIT you can't do much of anything between ticks AFAIK, especially if you're on an embedded system.

Anyway, thanks everyone for you help. I learned a lot!
In general, your statement was true only a few years ago. Since then, microcontrollers have had an incredible growth in computational horsepower. It makes being an electrical engineer a lot of fun right now, because we suddenly have gobs of "free" computation to throw at problems. We are literally able to replace physical objects with lines of code, and that is freaking cool.


For reference, the 2006 IFI controller's microcontroller was a PIC18F. These perform on average one 8 bit operation every 4 clock cycles. The Jaguar's microcontroller is an M3-Cortex, which on average performs 1.25 32 bit operations each clock cycle. If they were clocked at the same speed, the M3 performs 5 times as many operations and those operations do more work. Additionally, the associated peripherals do more of the work, and handle things like quadrature encoders without bothering the main core.

Long story short, there is so much additional capability that they end up running the core much slower than it is capable of.