Lowest Possible Clock For Blackfin 531

What is the lowest possible clock for BF531 (according to the
specifications..)... I checked out the datasheet but it says that it
can run upto 400 Mhz... No lower possible value is given... From where
to get this value?

adonis wrote:

> What is the lowest possible clock for BF531 (according to the
> specifications..)... I checked out the datasheet but it says that it
> can run upto 400 Mhz... No lower possible value is given... From where
> to get this value?

As I remember, the minimum XTAL frequency for BF53x is specified at 
10MHz. You can run the core at XTAL/2, i.e. at 5MHz.

Vladimir Vassilevsky

DSP and Mixed Signal Design Consultant

http://www.abvolt.com

Vladimir Vassilevsky wrote:
> adonis wrote:
>
> > What is the lowest possible clock for BF531 (according to the
> > specifications..)... I checked out the datasheet but it says that it
> > can run upto 400 Mhz... No lower possible value is given... From where
> > to get this value?
>
> As I remember, the minimum XTAL frequency for BF53x is specified at
> 10MHz. You can run the core at XTAL/2, i.e. at 5MHz.
>
> Vladimir Vassilevsky
>
> DSP and Mixed Signal Design Consultant
>
> http://www.abvolt.com

Ohh thats good.. my requirement is running it close to 23Mhz... so
25Mhz is ok for me..
 But where is it officially mentioned!!.. where do i refer for it..

adonis wrote:

>>As I remember, the minimum XTAL frequency for BF53x is specified at
>>10MHz. You can run the core at XTAL/2, i.e. at 5MHz.
>>
> Ohh thats good.. my requirement is running it close to 23Mhz... so
> 25Mhz is ok for me..

>  But where is it officially mentioned!!.. where do i refer for it..

Look into the datasheet and into the manual (clock and power management).

BTW, instead of using the BF at 23MHz, I would take some other MCU. If 
this amount of the computing power is sufficient, you can make the 
design much better and cheaper.


Vladimir Vassilevsky

DSP and Mixed Signal Design Consultant

http://www.abvolt.com

Vladimir Vassilevsky wrote:
> adonis wrote:
>
> >>As I remember, the minimum XTAL frequency for BF53x is specified at
> >>10MHz. You can run the core at XTAL/2, i.e. at 5MHz.
> >>
> > Ohh thats good.. my requirement is running it close to 23Mhz... so
> > 25Mhz is ok for me..
>
> >  But where is it officially mentioned!!.. where do i refer for it..
>
> Look into the datasheet and into the manual (clock and power management).
>
> BTW, instead of using the BF at 23MHz, I would take some other MCU. If
> this amount of the computing power is sufficient, you can make the
> design much better and cheaper.
>
>
> Vladimir Vassilevsky
>
> DSP and Mixed Signal Design Consultant
>
> http://www.abvolt.com

Yes thats right Mr. Vassilevsky, but i want to run it at 23 Mhz just to
estimate some of the timing requirements considering the base loop in
software. So, 23 MIPS dedicated for base loop. Large amount of MIPS is
required for ISR routines... thats y going for BF531.. actually
presently have 533.. thinking of cutting down cost.. so planning to use
531..

adonis wrote:
> What is the lowest possible clock for BF531 (according to the
> specifications..)... I checked out the datasheet but it says that it
> can run upto 400 Mhz... No lower possible value is given... From where
> to get this value?


According to the Datasheet:

CLKIN Min 10Mhz (Table 15)

Figure 8 CLKIN can be divided by 2 to 5Mhz to create VCO

Figure 8 VCO can be divided by 8 to create CCLK (core clock) so 5/8 Mhz
looks like the lowest

Curious what the power requirements are at this speed.