Lpc2000

Hi Folks,

Anyone know if there is a FIFO facility available for
the A/D? Reference is made to it on p240 of the
LPC2119/2129/2194/2292/2294 User Manual, bit 30 of
ADDR: In non-FIFO operation, this bit is cleared by
reading this register.

Is there an accumulator? Reference on the same page,
bits 23:16 These bits always read as zeroes. They
allow accumulation ...

Cheers,

Adam 


	
	
		
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--- In lpc2000@yahoogroups.com, Adam Wilkinson <lpc2129@y...> wrote:

> Anyone know if there is a FIFO facility available for
> the A/D? Reference is made to it on p240 of the
> LPC2119/2129/2194/2292/2294 User Manual, bit 30 of
> ADDR: In non-FIFO operation, this bit is cleared by
> reading this register.

There is no FIFO.  Conversions can be started either manually by 
writing to ADCR, by various MATx.x edges, or continuously in a 
sequence (burst mode).  You must read the result after each 
conversion.

> Is there an accumulator? Reference on the same page,
> bits 23:16 These bits always read as zeroes. They
> allow accumulation ...

There is no automatic accumulation.  When bits 32:16 are zero, you 
don't need to mask them away when adding up to 256 conversion 
results.  You can then do this:

  int acc = 0;
  for (...)
  {
    ...
    acc += ADCR;
  }
  acc &= 0x00FFFFC0;

instead of this:

  int acc = 0;
  for (...)
  {
    ...
    acc += (ADCR & 0x0000FFC0);
  }

It is a small feature with a small benefit.

Regards,
Karl Olsen