Stall behavior and error recovery, Stall behavior and error recovery -12 – Altera Video and Image Processing Suite User Manual

Page 18

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IP Core

Configuration

ALM

RAM

DSP

Scaler II

• Symbols in parallel = 3

• Scaling algorithm = Polyphase

• Enable run-time control of input/output

frame size = On

• Vertical/horizontal filter taps = 4

• Vertical/horizontal filter phases = 14

1,010

12

12

Test Pattern

Generator

• Color space = RGB

• Run-time control of image size = Off

65

0

0

Trace System

• Buffer size = 8192

• Bit width of capture interface(s) = 32

• Number of inputs = 2

1,224

12

0

Stall Behavior and Error Recovery

The Video and Image Processing Suite IP cores do not continuously process data. Instead, they use flow-

controlled Avalon-ST interfaces, which allow them to stall the data while they perform internal

calculations.
During control packet processing, the IP cores might stall frequently and read or write less than once per

clock cycle. During data processing, the IP cores generally process one input or output per clock cycle.

There are, however, some stalling cycles. Typically, these are for internal calculations between rows of

image data and between frames/fields.
When stalled, an IP core indicates that it is not ready to receive or produce data. The time spent in the

stalled state varies between IP cores and their parameterizations. In general, it is a few cycles between rows

and a few more between frames.
If data is not available at the input when required, all of the IP cores stall and do not output data. With the

exceptions of the Deinterlacer and Frame Buffer in double or triple-buffering mode, none of the IP cores

overlap the processing of consecutive frames. The first sample of frame

F

+ 1 is not input until after the IP

cores produce the last sample of frame

F

.

When the IP cores receive an

endofpacket

signal unexpectedly (early or late), the IP cores recover from

the error and prepare for the next valid packet (control or data).

1-12

Stall Behavior and Error Recovery

UG-VIPSUITE

2015.05.04

Altera Corporation

Video and Image Processing Suite Overview

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