I want to generate a continuous waveform from the AD9106 that outputs the waveform loaded into the device SRAM.
I configure the WAVE SELECT register, 0x27, to run a waveform read from RAM between START_ADDR1 and STOP_ADDR1 for WAVE_SEL1.
I load the 12 bit waveform into the SRAM locations 0x6fff to 0x6000. The waveform is linear ramp with values 0 to 4095.
I set the 12 bit left justified start and stop addresses for DAC1 into registers 0x5d and 0x5e.
I select a continuous waveform in the pattern type register, 0x1f.
I set all the values to 0 for the pattern time base register, 0x28. I use the default value in the patter period register.
I set the analog gain to 90 and the digital gain to 500, registers 0x07 and 0x35.
I set the bit to run the waveform in register 0x1e, pattern status register.
I set the external trigger bit low to start the waveform.
The waveform starts to run, the pattern generator on bit is set in register 0x1e.
I observe a very small waveform of only 4 0.003 V steps at OUT1 for DAC1 with a 220 micro-sec period.
There is a configuration error bit set, bit 4, in register 0x60: "When period register setting value is smaller than pattern play cycle, this error is toggled."
What am I doing wrong? I also don't understand what the output from the SRAM should look like relative to the values loaded in to that address space.