AD73311 + LPC3250 interface and software


     We designed a system using AD73311 codec interfacing with AMBE2000 Vocoder. We interfaced AD73311 to LPC3250 SPI interface as per the AMBE2000 datasheet as shown below. But we used LPC3250 ( SPI interface ) instead of DSP micro controller.

We programmed the registers as shown below

  ctrl_regs[0] = AD_CONTROL | AD_WRITE | CTRL_REG_A | REGA_ALB;

          ctrl_regs[1] = AD_CONTROL | AD_WRITE | CTRL_REG_B | REGB_MCDIV(0) | \

                              REGB_SCDIV(0) | REGB_DIRATE(0);

          ctrl_regs[2] = AD_CONTROL | AD_WRITE | CTRL_REG_C | REGC_PUDEV | \

                              REGC_PUADC | REGC_PUDAC | REGC_PUREF | REGC_REFUSE  ;

          ctrl_regs[3] = AD_CONTROL | AD_WRITE | CTRL_REG_D | REGD_OGS(2) | \


          ctrl_regs[4] = AD_CONTROL | AD_WRITE | CTRL_REG_E | REGE_DA(0x1f);

          ctrl_regs[5] = AD_CONTROL | AD_WRITE | CTRL_REG_A | REGA_MODE_DATA;

We are trying to check analog loop back. But nothing happening. And, we checked the data on AD73311 pins ( Input) using oscilloscope. It is fine.

So, What might be the problem?

Is SPI interface makes any difference?

We are sending Clock and Frame sync from our Micro controller.Is this makes any problem?

Any reference Code available? Please help...

I'm attaching the schematic below.

Thanks Regards


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