Lpc2000

Thanks for the suggestions.

It's working OK now (sine, triangle, sawtooth and square waves) with the
following code:

 adder = 202500;               //set up adder
  acc = 0;                    //clear accumulator
  while (1)
  {
    acc = acc + adder;      //update phase accumulator
    ptr = (acc &= 0xFF);    //pointer into table
    IOSET = sawtooth[ptr] << 8;
    IOCLR = (~sawtooth[ptr] << 8);
   }

apart from glitches - spurs on the waveforms. I think I had the ~ in the
wrong place.

I didn't get those glitches with the AVR, using the same DAC. I've got some
LEDs on some of the lines to the DAC, so I'll try disconnecting them - they
might be pulling the signals down. Although the DAC is a 5V device,
according to the spec it is LV CMOS compatible (as low as 2V for a logic
high) on the inputs, so it should be OK with the LPC2106 outputs. I might
try pulling the inputs up to 5V if I still have problems.

Leon
--
Leon Heller, G1HSM
Email: aqzf13@...
http://www.geocities.com/leon_heller