By: David Kanter (dkanter.delete@this.realworldtech.com), May 28, 2013 11:14 am
Room: Moderated Discussions
Sebastian Soeiro (sebastian_2896.delete@this.hotmail.com) on May 28, 2013 9:00 am wrote:
> David Kanter (dkanter.delete@this.realworldtech.com) on May 6, 2013 2:30 pm wrote:
> > Silvermont is Intel’s first CPU core tailored for power efficient applications such as smartphones,
> > tablets, and microservers. The 22nm microarchitecture features updated instruction set extensions,
> > full out-of-order execution with a tightly coupled L2 cache, aggressive power management, and a new
> > high performance SoC fabric. These enhancements deliver tremendous performance and frequency gains
> > over the aging Atom core, putting Intel’s mobile strategy in a more competitive position.
> >
> > My detailed look at the microarchitecture is online: http://www.realworldtech.com/silvermont/
> >
> > Comments and questions are welcome, let the discussion begin!
> >
> > David
>
> I have a question;
>
> If Silvermont uses RSV banks for every execution unit function, and the execution units
> simply "sucks" in the next instruction to execute as the previous one is finished, what
> is there to prevent dependancy errors? Sorry, I'm quite a bit new to CPU architecture
> and want to learn lots, so I apologize if this is a very newbish question.
That's a good question. Reservation stations perform dependency checking:
"...each distributed scheduler will dispatch the oldest, ready to execute µop to the appropriate port."
http://www.realworldtech.com/silvermont/5/
So if the oldest instruction is still waiting on a register, then the next oldest will be chosen. If all 8 entries are waiting, then nothing is sent.
The memory RSV is a little different though.
David
> David Kanter (dkanter.delete@this.realworldtech.com) on May 6, 2013 2:30 pm wrote:
> > Silvermont is Intel’s first CPU core tailored for power efficient applications such as smartphones,
> > tablets, and microservers. The 22nm microarchitecture features updated instruction set extensions,
> > full out-of-order execution with a tightly coupled L2 cache, aggressive power management, and a new
> > high performance SoC fabric. These enhancements deliver tremendous performance and frequency gains
> > over the aging Atom core, putting Intel’s mobile strategy in a more competitive position.
> >
> > My detailed look at the microarchitecture is online: http://www.realworldtech.com/silvermont/
> >
> > Comments and questions are welcome, let the discussion begin!
> >
> > David
>
> I have a question;
>
> If Silvermont uses RSV banks for every execution unit function, and the execution units
> simply "sucks" in the next instruction to execute as the previous one is finished, what
> is there to prevent dependancy errors? Sorry, I'm quite a bit new to CPU architecture
> and want to learn lots, so I apologize if this is a very newbish question.
That's a good question. Reservation stations perform dependency checking:
"...each distributed scheduler will dispatch the oldest, ready to execute µop to the appropriate port."
http://www.realworldtech.com/silvermont/5/
So if the oldest instruction is still waiting on a register, then the next oldest will be chosen. If all 8 entries are waiting, then nothing is sent.
The memory RSV is a little different though.
David