Reply by brendanmurphy37 July 4, 20062006-07-04
--- In l..., "jayasooriah" wrote:

> The problem I find with MAM that it is speculative and does not work
> when your application behaves differently.
>

Can you explain the circumstances in which the MAM doesn't work?

Brendan.

An Engineer's Guide to the LPC2100 Series

Reply by jayasooriah July 3, 20062006-07-03
Oops, I meant 128- or 256-BIT wide banks, not byte wide!

--- In l..., "jayasooriah" wrote:
>
> --- In l..., "arrek_x" wrote:
> >
> > In LPC21xx devices below series LPC213x Flash memory is split into
two
> > Flash banks and code is being fetched alternately form those banks.
> > OK, fine - it looks simple :). But what about the way of MAM working
> > in LPC213x, where only one Flash bank is used? I suspect, that code
> > must be fetched from Flash in similar manner, because it's core rule
> > of accerelating program execution. But how is it exactly performed,
> > when only one bank is present? I was trying to find something but
> > found nothing relevant to that subject, and manual is rather laconic
> > and cloudy in MAM section.
> >
> > Regards,
> > A.
>
> The MAM on LPC is not much more than a traditional pre-fetch queue
> with limited look-ahead capability. Dual 128- or single 255-byte
> banking does not seem to matter much other than reducing peak currents.
>
> The problem I find with MAM that it is speculative and does not work
> when your application behaves differently.
>
> Jaya
>

Reply by jayasooriah July 3, 20062006-07-03
--- In l..., "arrek_x" wrote:
>
> In LPC21xx devices below series LPC213x Flash memory is split into two
> Flash banks and code is being fetched alternately form those banks.
> OK, fine - it looks simple :). But what about the way of MAM working
> in LPC213x, where only one Flash bank is used? I suspect, that code
> must be fetched from Flash in similar manner, because it's core rule
> of accerelating program execution. But how is it exactly performed,
> when only one bank is present? I was trying to find something but
> found nothing relevant to that subject, and manual is rather laconic
> and cloudy in MAM section.
>
> Regards,
> A.

The MAM on LPC is not much more than a traditional pre-fetch queue
with limited look-ahead capability. Dual 128- or single 255-byte
banking does not seem to matter much other than reducing peak currents.

The problem I find with MAM that it is speculative and does not work
when your application behaves differently.

Jaya

Reply by arrek_x July 3, 20062006-07-03
In LPC21xx devices below series LPC213x Flash memory is split into two
Flash banks and code is being fetched alternately form those banks.
OK, fine - it looks simple :). But what about the way of MAM working
in LPC213x, where only one Flash bank is used? I suspect, that code
must be fetched from Flash in similar manner, because it's core rule
of accerelating program execution. But how is it exactly performed,
when only one bank is present? I was trying to find something but
found nothing relevant to that subject, and manual is rather laconic
and cloudy in MAM section.

Regards,
A.