
Functional Overview
179
December 2003 Revised March 2005
SPRS231D
3.8.5 I
2
C Master/Slave Interface
The multimaster I
2
C peripheral provides an interface between a local host (LH), such as an MPU or DSP
processor, and any I
2
C bus compatible device that connects via the I
2
C serial bus. External components
attached to the I
2
C bus can serially transmit/receive up to 8 bits of data to/from the LH device or a DMA through
the I
2
C interface. This I
2
C peripheral supports any slave or master I
2
C-compatible device.
The I
2
C bus is a multimaster bus. The I
2
C controller supports the multimaster mode, which allows more than
one device capable of controlling the bus to be connected to it. Each I
2
C device is recognized by a unique
address and can operate as either transmitter or receiver, depending on the function of the device. In addition
to being a transmitter or receiver, the device connected to the I
2
C bus can also be considered a master or a
slave when performing data transfers. Note that a master device is the device which initiates a data transfer
on the bus and generates the clock signals to enable that transfer. During the latter, any device addressed
by this master is considered a slave.
The I
2
C interface with the local host is compliant with 8-/16-bit OCP protocol. The interface clock and the
functional clock are independent. The I
2
C master/slave interface supports the following features:
Compliant to Philips I
2
C-bus specification version 2.1
Support standard mode (up to 100K bits/s) and fast mode (up to 400K bits/s)
In the master only I
2
C operating mode of OMAP5912, standard mode is supported up to 83K bits/s.
7-bit and 10-bit device addressing modes
General call
Start/restart/stop
Multimaster transmitter/slave receiver mode
Multimaster receiver/slave transmitter mode
Combined master transmit/receive and receive/transmit mode
Built-in FIFO for buffered read or write
Module enable/disable capability
Programmable clock generation
Supports use of two DMA channels
The I
2
C master/slave interface does not support the following features:
High-speed (HS) mode for transfer rates up to 3.4M bits
C-bus compatibility mode
3.8.6 Multichannel Buffered Serial Port (McBSP2)
The multichannel buffered serial port (McBSP) provides a high-speed, full-duplex serial port that allows direct
interface to audio codecs, and various other system devices. The McBSP provides:
Full-duplex communication
Double-buffer data registers, which allow a continuous data stream
Independent framing and clocking for receive and transmit