A2B - AD2428W as Master and AD2428W as Slave

Here is A2B AD2428W block diagram as below, 

Master side : I2S input to CPU (from salve PDM MIC)

Master side : I2S otuput to Slave node for speaker out

Can they use the same BCLK and Sync?

Slave side :PDM MIC input through PDM channel

Salve side : I2S output to audio AMP for speaker output.

Is the connection correct?

Thanks. 

  • 0
    •  Analog Employees 
    on Sep 25, 2020 8:12 AM

    Hi Gen,

    Apologies for the slow response.

    Your connections look correct. Regarding the SYNC and BCLK pins, please note that, as per the AD242x/242xW Technical Reference Manual (Rev. 1.1), the I2S/TDM serial port operates in full-duplex mode, where both the transmitter and receiver operate simultaneously using the same critical timing bit clock (BCLK) and frame synchronization (SYNC) signals. A2B slave transceivers generate the timing signals on the BCLK and SYNC output pins with frequencies based on the settings in the I2S global configuration register ( A2B_I2SGCFG ), the I2S rate register ( A2B_I2SRATE ), and the I2S reduced rate register ( A2B_I2SRRATE ). A2B master transceivers use the same BCLK and SYNC pins as inputs, which are driven by the host, thus providing the time base for the full A2B bus topology.

    I hope this helps.

    Best regards,

    MKB

  • Hi Mkokaly, 
    Thank you for your detailed explanation and techinical sharing.

    The other question is what default setting of I2C address is?
    The model is point to point (1 master and 1 slave)
    ADR1 and ADR2 of Master node connect to GND ?
    ADR1 and ADR2 of Slave node connect to GND   ?

    Thanks. 

  • 0
    •  Analog Employees 
    on Sep 25, 2020 8:44 AM in reply to gen

    Hi Gen,

    Please refer to the "I2C Interface" section of the  AD242x/242xW Technical Reference Manual (Rev. 1.1) - Pages 2-8 and 2-9 for details on the I2C device adddress and ADR1/ADR2 pins. 

    A2B supports direct point to point connection and allows multiple, daisy-chained nodes. A2B bus topology can consist of multiple daisy-chained slave nodes (up to 10 slave nodes) connected to a single master node.

    Best regards,

    MKB