6.10.10 McBSP
The Multi-channel Buffered Serial Port (McBSP) provides a full-duplex serial communication interface between the device and other devices in a system. The primary use for the McBSP is for audio interface purposes. The main audio modes that are supported are the AC97 and I2S modes. In addition to the primary audio modes, the McBSP can be programmed to support other serial formats but is not intended to be used as a high-speed interface. The device communicates to the McBSP using 32-bit-wide control registers accessible via the internal peripheral bus.
The McBSP provides the following functions:
- Full-duplex communication
- Double-buffered data registers, which allow a continuous data stream
- Independent framing and clocking for receive and transmit
- Direct interface to industry-standard codecs, analog interface chips (AICs), and other serially connected analog-to-digital (A/D) and digital-to-analog (D/A) devices
- External shift clock or an internal, programmable frequency shift clock for data transfer
In addition, the McBSP has the following capabilities:
- Direct interface to:
- T1/E1 framers
- MVIP switching compatible and ST-BUS compliant devices including:
- MVIP framers
- H.100 framers
- SCSA framers
- IOM-2 compliant devices
- AC97 compliant devices (the necessary multiphase frame synchronization capability is provided)
- I2S compliant devices
- Multi-channel transmit and receive of up to 128 channels
- A wide selection of data sizes, including 8, 12, 16, 20, 24, and 32 bits
- μ-Law and A-Law companding
- 8-bit data transfers with the option of LSB or MSB first
- Programmable polarity for both frame synchronization and data clocks
- Highly programmable internal clock and frame generation
- Additional McBSP Buffer FIFO (BFIFO):
- Provides additional data buffering
- Provides added tolerance to variations in host/DMA controller response times
- May be used as a DMA event pacer
- Independent Read FIFO and Write FIFO
- 256 bytes of RAM for each FIFO (read and write)
- Option to bypass Write FIFO and/or Read FIFO, independently
McBSP module unsupported features:
- The McBSP on this device does not support the SPI protocol.
- 512 Channel Mode
- Individual enable/disable channel control
- Timeslot buffering
- Super frame synchronization
- ABIS Mode
For more information, see section Multi-channel Buffered Serial Port (McBSP) in chapter Peripherals of the Device TRM.