2.2 I2S Mode Application

The BM23 module provides an I2S digital audio signal interface to connect with an external Codec/DSP. It provides 8, 44.1 and 48 kHz sampling rates for 16-bit and 24-bit data formats. The I2S setting can be configured by using the UI and DSP tools.

The external Codec/DSP is connected to SLK0, RFS0, TFS0, DR0, and DT0 (pins 4, 2, 3, 5, and 6 respectively). The I2S signal connection between the BM23 and external DSP is illustrated in the following figure.

Figure 2-8. Master Mode Reference Connection

The Slave mode reference connection is shown in the following figure.

Figure 2-9. Slave Mode Reference Connection
Note:
  1. For 002 version chip or module, the system must connect line 1 in the above figure.
  2. For other version chip or module, the system must connect line 2 in the above figure.

For Master or Slave mode setting, use the DSP Configuration Tool to set up the system. The following figures illustrate the clock and data timing diagram.

Figure 2-10. Timing for I2S Modes (both Master and Slave)

The following figures illustrate the timing diagram in the PCM modes.

Figure 2-11. Timing Diagram for PCM Modes (Master/Slave)