User guide

January 2013 Altera Corporation Video and Image Processing Suite
User Guide
3. Interfaces
Interface Types
The MegaCore functions in the Video and Image Processing Suite use standard
interfaces for data input and output, control input, and access to external memory.
These standard interfaces ensure that video systems can be quickly and easily
assembled by connecting MegaCore functions together.
The functions use the following types of interfaces:
■ Avalon-ST interface—a streaming interface that supports backpressure. The
Avalon-ST Video protocol transmits video and configuration data. This interface
type allows the simple creation of video processing data paths, where MegaCore
functions can be connected together to perform a series of video processing
functions.
■ Avalon-MM slave interface—provides a means to monitor and control the
properties of the MegaCore functions.
■ Avalon-MM master interface—when the MegaCore functions require access to a
slave interface, for example an external memory controller.
f For more information about these interface types, refer to the Avalon Interface
Specifications.
Figure 3–1 shows an example of video processing data paths using the Avalon-ST and
Avalon-MM interfaces. This abstracted view is similar to that provided in the Qsys
tool, where interface wires are grouped together as single connections.
The Clocked Video Input and Clocked Video Output MegaCore functions in
Figure 3–1 also have external interfaces that support clocked video standards. These
MegaCore functions can connect between the function’s Avalon-ST interfaces and
functions using clocked video standards such as BT.656.
Figure 3–1. Abstracted Block Diagram Showing Avalon-ST and Avalon-MM Connections
Clocked Video
Input MegaCore
Function
Deinterlacer
MegaCore
Function
High Performance
DDR 2 Memory
Controller MegaCore
Function
Nios II
Processor
Avalon ST Connection
Avalon MM Master to Slave Connection
Scaler
MegaCore
Function
Clocked Video
Output MegaCore
Function