Virtual Streaming Interface (VSI)

Data streaming interface. More...

Content
	Python environment
	Python environment for Arm FVPs.
	VSI API
	Virtual Streaming Interface API for application firmware.
	VSI Python interface
	VSI python interface.
	VSI Use Cases
	Use Cases for Virtual Streaming Interface (VSI)

Description

Data streaming interface.

The Virtual Streaming Interface (VSI) is a flexible memory-mapped peripheral available in Arm Fixed Virtual Platforms (FVPs). It can be used to simulate data streaming interfaces such as audio, video and various sensors often found in IoT and Machine-Learning applications. The VSI is provided in 8 independent instances that can be used in parallel for multi-channel input/ouput interfaces.

Figure below illustrates the concept behind the VSI on Arm FVPs.

Using the Virtual Streaming Interface (VSI)

• On the application firmware side a peripheral driver uses the VSI registers in the FVP model to simulate peripheral operation for a target use case. By relying on common driver APIs the same application-level code can be reused for FVPs and real hardware targets.
• Read/write accesses to the VSI peripheral registers in the FVP trigger execution of corresponding callback functions in the VSI Python scripts that implement peripheral behavior in the target scenario.
• An FVP model can be run on a Windows or Linux host and executes the target firmware application image. The path to the VSI python scripts shall be provided to the FVP using the command-line option -V, or --v_path, see Running User Applications.

Section VSI Use Cases explains in details the reference implementations of VSI-based peripherals. Specifically Audio via VSI implementing audio streaming input from a local audio wave file and Video via VSI implementing video streaming from a local video or image file.

Access to the VSI peripherals is defined in the following files:

File	Description
./interface/include/arm_vsi.h	VSI API header file
./interface/python/arm_vsi0.py	VSI Python interface script template for instance 0
:	:
./interface/python/arm_vsi7.py	VSI Python interface script template for instance 7

An example flow for using the VSI peripheral is shown on the figure below:

Example flow for using the VSI peripheral