Lpc2000

Hi all,

I would like to knwo what is exactly fast I/O because I have not found
anything about timing on the LPC214x datasheets...

Thanks in advance

Hi

I think that fast IO is a feature in recent released versions of ARM.
It's an IO's connected directly to AHP of AMBA bus and not throgh APB
You can check ARM web site

Salam
Hossam Alzomor
www.i-g.org

You should refer to the LPC214x *user manual*  UM10139.    Chapter 8 
covers GPIO.  The fast GPIO "FIO" is implemented as a second set 
registers that acess the IO pins much faster.  Fig.17 on page 82 shows 
relitive timing.  Very simple to use. 

Ian 

--- In lpc2000@yahoogroups.com, "croquettegnu" <croquettegnu@...> wrote:

>
> Hi all,
> 
> I would like to knwo what is exactly fast I/O because I have not found
> anything about timing on the LPC214x datasheets...
> 
> Thanks in advance
>

What about the maximum speed in Mbit/s on these Fast I/O ?

--- In lpc2000@yahoogroups.com, "ian.scanlon" <scanlon.design@...> wrote:

>
> You should refer to the LPC214x *user manual*  UM10139.    Chapter 8 
> covers GPIO.  The fast GPIO "FIO" is implemented as a second set 
> registers that acess the IO pins much faster.  Fig.17 on page 82 shows 
> relitive timing.  Very simple to use. 
> 
> Ian 
> 
> --- In lpc2000@yahoogroups.com, "croquettegnu" <croquettegnu@> wrote:
> >
> > Hi all,
> > 
> > I would like to knwo what is exactly fast I/O because I have not found
> > anything about timing on the LPC214x datasheets...
> > 
> > Thanks in advance
> >
>

--- In lpc2000@yahoogroups.com, "Hossam Alzomor" <zomorh@...> wrote:
>
> Hi
> 
> I think that fast IO is a feature in recent released versions of ARM.
> It's an IO's connected directly to AHP of AMBA bus and not throgh APB
> You can check ARM web site
> 
> Salam
> Hossam Alzomor
> www.i-g.org
>
Close but not quite correct,

some other devices of other manufacturers have connected the I/O to 
the AHB bus but there are still some delays on the AHB although it is 
definitely faster than using the APB (= VPB). The fastest bus in an 
ARM7 system is the local memory bus. 
The Philips LPC214x and LPC2101/2/3 have I/O pins connected to the 
local bus. 

Max frequency you can achieve is CPU/4 so, a 60 MHz device can 
generate a 15 MHz output. Keep in mind that this is all CPU driven and 
while generating a 15 MHz output, you are not going to do anything 
else. 

Robert

Thats a pretty good question really. The manual isn't the best thing 
to clarify this. Heres my take...

Fast I/O should always be used as its the norm. The old I/O is 
just "legacy stuff". You don't use your 56k modem at 14k4 even though 
it supports it do you?

Speed of the I/O.... thats a loaded question.

Using Keil C I can get the Pin wiggling at over 3 MHz, (almost half 
as fast as my Silabs 8051 using C, pardon the pun) Under assembly you 
can get the port to wiggle at about 15 Mhz (theoretically). This 
requires certain registers to be frozen to the port address and is 
not C friendly.

One thing about these arm chips is you need to use the hardware as 
much as possible as thats whats good about them. Bit banging is not 
their specialty as everything is 32 bits. 

PS dont forget the fast I/O's are byte addressable if you add some 
defines to the LPC24??.H

Cheers
Keith


> >
> > Hi all,
> > 
> > I would like to knwo what is exactly fast I/O because I have not 
found

> > anything about timing on the LPC214x datasheets...
> > 
> > Thanks in advance
> >
>