PDA

View Full Version : instruction size on C672x


SYL
09-10-2008, 11:21 PM
Hi,

Am I right to say this?

On c672x, instructions are 32 bit natively. To make full use of the
two data paths, 8 instructions or 256 bits are needed. So 1k actual
instructions may take from 4k up to 32k bytes.

Thanks
syl

Brad Griffis
09-11-2008, 04:46 AM
SYL wrote:
> Hi,
>
> Am I right to say this?
>
> On c672x, instructions are 32 bit natively. To make full use of the
> two data paths, 8 instructions or 256 bits are needed. So 1k actual
> instructions may take from 4k up to 32k bytes.
>
> Thanks
> syl

1 instruction = 32 bits
1k instructions = 32k bits

There are 8 functional units so up to 8 instructions can be executed per
cycle. Two of those functional units are load/store units hence the two
data paths. So to make full use of the two data paths you would only
need two instructions per cycle. Of course I imagine you'll want to
process that data so likely you'll want more instructions per cycle.

Brad