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AD73311 + LPC3250 interface and software

Question asked by Eswar on Jun 10, 2013
Latest reply on Oct 13, 2014 by DaveThib

Hi,

     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.

 

voc1.JPG

 

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) | \

                              REGD_IGS(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.

 

voc1.JPG

 

Thanks Regards

Eswar

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