UG-VIPSUITE	Avalon-ST Video Protocol	2-7
	2015.01.23

Figure 2-6: Separate Synchronization Signals Timing Diagram

vid_data

D0

D1

DN

Dn+1 Dn+2

vid_de/vid_datavalid (1)

vid_v_sync

vid_h_sync

vid_f

(1): vid_datavalid: Clocked Video Output IP core vid_de: Clocked Video Input IP core

The CVI IP cores only read the vid_data, vid_de, vid_h_sync, vid_v_sync, and vid_f signals when vid_datavalid is 1. This allows the CVI IP cores to support oversampling where the video clock is running at a higher rate than the pixel clock.

Video Locked Signal

The vid_locked signal indicates that the clocked video stream is active. When the signal has a value of 1, the CVI IP cores take the input clocked video signals as valid, and read and process them as normal. When the signal has a value of 0 (if for example the video cable is disconnected or the video interface is not receiving a signal):

•Clocked Video Input IP core: The IP core takes the input clocked video signals as invalid and do not process them.

•Clocked Video Input II IP core: The vid_clk domain registers of the IP core are held in reset and no video is processed. The control and Avalon-ST Video interfaces are not held in reset and will respond as normal. The vid_locked signal is synchronized internally to the IP core and is asynchronous to the

vid_clk.

If the vid_locked signal goes invalid while a frame of video is being processed, the CVI IP cores end the frame of video early.

Avalon-ST Video Protocol

The Avalon-ST Video protocol is a packet-oriented way to send video and control data over Avalon-ST connections. The IP cores in the Video and Image Processing Suite use the Avalon-ST Video protocol.

Using the Avalon-ST Video protocol allows the construction of image processing data paths which automatically configure to changes in the format of the video being processed. This minimizes the external control logic required to configure a video system.

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2-8		Avalon-ST Video Protocol								UG-VIPSUITE
									2015.01.23
	Table 2-3: Avalon-ST Video Protocol Parameters
						Parameter Values
		IP Cores		Frame Width/		Interlaced/		Bits per Color		Color Pattern
				Height		Progressive		Sample
		2D FIR Filter		User-defined—		Progressive		User-defined—		One, two, or three
				through				through		channels in sequence.
				parameter editor				parameter editor
		Alpha Blending Mixer		Run-time		Progressive		User-defined—		• din and dout: One,
				controlled				through		two or three
								parameter editor		channels in
								Specified		sequence
								separately for		• alpha_in: A single
								image data and		color plane
								alpha blending.		representing the
										alpha value for each
										pixel
		Mixer II		No run-time		Progressive		User-defined—		Two or three channels
				control				through		in parallel.
								parameter editor
		Chroma Resampler		Run-time		Progressive		User-defined—		User-defined—through
				controlled				through		parameter editor
								parameter editor
		Clipper/Clipper II		Run-time		Either one—		User-defined—		Any combination of
				controlled		interlaced inputs		through		one, two, three, or four
						are accepted but		parameter editor		channels in each of
						treated as				sequence or parallel.
						progressive
						inputs.
		Color Plane Sequencer		Run-time		Either one		User-defined—		User-defined—through
				controlled				through		parameter editor
								parameter editor
		Color Space Converter		Run-time		Either one		User-defined—		Three color planes in
				controlled				through		parallel or sequence
								parameter editor
		Color Space Converter		No run-time		Either one		User-defined—		Three color planes in
		II		control				through		parallel or sequence
								parameter editor
		Control Synchronizer		Run-time		Run-time		User-defined—		Up to four color planes
				controlled		controlled		through		in parallel, with any
								parameter editor		number of color planes
										in sequence.

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UG-VIPSUITE							Avalon-ST Video Protocol			2-9
2015.01.23
					Parameter Values
	IP Cores		Frame Width/		Interlaced/		Bits per Color		Color Pattern
			Height		Progressive		Sample
	Deinterlacer		Run-time		Interlaced input		User-defined—		• One, two, or three
			controlled		and progressive		through		channels in
					output (plus		parameter editor		sequence
					optional				• alpha_in: A single
					passthrough
									color plane
					mode for
									representing the
					progressive
									alpha value for each
					input)
									pixel
	Deinterlacer II		Run-time		Interlaced input		User-defined—		Any combination of
			controlled		and progressive		through		two or three channels
					output (plus		parameter editor		in each of parallel.
					passthrough
					mode for
					progressive
					input)
	Broadcast Deinterlacer		Run-time		Interlaced input		User-defined—		Two channels in
			controlled		and progressive		through		parallel (4:2:2 only)
					output (plus		parameter editor
					passthrough
					mode for
					progressive
					input)
	Frame Reader		User-defined—		User-defined—		User-defined—		Up to four color planes
			through Avalon-		through Avalon-		through		in parallel, with up to
			MM slave		MM slave		parameter editor		three color planes in
			control port		control port				sequence.
	Frame Buffer		Run-time		Progressive; in		User-defined—		Any combination of
			controlled		some cases		through		one, two, three, or four
					interlaced data		parameter editor		channels in each of
					accepted				sequence or parallel.
	Frame Buffer II		No run-time		Progressive		User-defined—		Any combination of
			control		inputs only		through		one, two, three, or four
							parameter editor		channels in each of
									parallel.
	Gamma Corrector		Run-time		Either one		User-defined—		One, two or three
			controlled				through		channels in sequence
							parameter editor		or parallel.

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2-10		Avalon-ST Video Protocol								UG-VIPSUITE
									2015.01.23
						Parameter Values
		IP Cores		Frame Width/		Interlaced/		Bits per Color		Color Pattern
				Height		Progressive		Sample
		Interlacer		Run-time		Progressive;		User-defined—		One, two or three
				controlled		interlaced data is		through		channels in sequence
						either discarded		parameter editor		or parallel.
						or propagated
						without change
						in parameter
						editor
		Test Pattern Generator		User-defined—		User-defined—		User-defined—		One, two or three
				through		through		through		channels in sequence
				parameter editor		parameter editor		parameter editor		or parallel.
				or run-time
				controlled
		Test Pattern Generator		User-defined—		User-defined—		User-defined—		RGB 4:4:4 or YCbCr
		II		through		through		through		4:4:4, 4:2:2 or 4:2:0 in
				parameter editor		parameter editor		parameter editor		parallel or sequence.
				or run-time
				controlled

Packets

The packets of the Avalon-ST Video protocol are split into symbols—each symbol represents a single piece of data. For all packet types on a particular Avalon-ST interface, the number of symbols sent in parallel (that is, on one clock cycle) and the bit width of all symbols is fixed. The symbol bit width and number of symbols sent in parallel defines the structure of the packets.

The functions predefine the following three types of packet:

•Video data packets containing only uncompressed video data

•Control data packets containing the control data configure the cores for incoming video data packets

•Ancillary (non-video) data packets containing ancillary packets from the vertical blanking period of a video frame

Another seven packet types are reserved for users, and five packet types reserved for future definition by Altera.

The packet type is defined by a 4-bit packet type identifier. This type identifier is the first value of any packet. It is the symbol in the least significant bits of the interface. Functions do not use any symbols in parallel with the type identifier.

Table 2-4: Avalon-ST Video Packet Types

Type Identifier		Description
0		Video data packet
1–8		User packet types
9–12		Reserved for future Altera use

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