IPSR-VIDEO Altera, IPSR-VIDEO Datasheet - Page 154

• Manufacturer Part Number: IPSR-VIDEO
• Description: RENEWAL Of IPS-VIDEO
• Manufacturer: Altera
• Series: IP Suitesr

Specifications of IPSR-VIDEO

• Software Application: IP CORE, SUITES
• Supported Families: Arria GX, Cyclone II, HardCopy II, Stratix II
• Features: Common Avalon Streaming (Avalon-St) Interface And Avalon-St Video Protocol
• Core Architecture: FPGA
• Core Sub-architecture: Arria, Cyclone, Stratix
• Rohs Compliant: NA
• Lead Free Status / RoHS Status: na

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Video and Image Processing Suite User Guide
Scaler II
Switch
In the Scaler II MegaCore function, the ratio of reads to writes is proportional to the
scaling ratio and occurs on both a per-pixel and a per-line basis. The frequency of lines
where reads and writes occur is proportional to the vertical scaling ratio. For example,
scaling up vertically by a factor of 2 results in the input being stalled every other line
for the length of time it takes to write one line of output; scaling down vertically by a
factor of 2 results in the output being stalled every other line for the length of time it
takes to read one line of input.
In a line that has both input and output active, the ratio of reads and writes is
proportional to the horizontal scaling ratio. For example, scaling from 64×64 to
128×128 causes 128 lines of output, where only 64 of these lines have any reads in
them. For each of these 64 lines, there are two writes to every read.
The internal latency of the Scaler II depends on the scaling algorithm and whether any
run time control is enabled. The scaling algorithm impacts stalling as follows:
■
■
Enabling run-time control of resolutions affects stalling between frames:
■
■
Error Recovery
On receiving an early endofpacket signal, the Scaler stalls its input but continues
writing data until it has sent an entire frame. If it does not receive an endofpacket
signal at the end of a frame, the Scaler discards data until the end-of-packet is found.
On receiving an early endofpacket signal at the end of an input line, the Scaler II stalls
its input but continues writing data until it has sent on further output line. On
receiving an early endofpacket signal part way through an input line, the Scaler II
stalls its input for as long as it would take for the open input line to complete,
completing any output line that may accompany that input line. It then continues to
stall the input, and writes one further output line. If it does not receive an
endofpacket signal at the end of a frame, the Scaler II discards data until the end-of-
packet is found.
The Switch MegaCore function only stalls its inputs when performing an output
switch. Before switching its outputs it synchronize all its inputs and during this
synchronization the inputs may be stalled.
In bilinear mode, a complete line of input is read into a buffer before any output is
produced. At the end of a frame there are no reads as this buffer is drained. Exactly
how many writes are possible during this time depends on the scaling ratio.
In polyphase mode with N
buffers before any output is ready. As with bilinear mode, there is a scaling ratio
dependent time at the end of a frame where no reads are needed as the buffers are
drained.
With no run-time control, there are about 10 cycles of delay before the behavior
described in the previous list begins, and about 20 cycles of further stalling
between each output line.
Enabling run-time control of resolutions adds about 25 cycles of delay between
frames.
v
vertical taps, N
v
– 1 lines of input are read into line
Chapter 5: Functional Descriptions
January 2011 Altera Corporation
Stall Behavior and Error Recovery