Method and system for detecting and performing automatic bank switching for a filter coefficient ram
View Patent ↗A method for facilitating a dual-bank filter coefficient RAM designed to switch banks automatically during the vertical blanking interval in a television application. The method and system of the present invention allows a micro controller to program a new set of filter coefficients in the memory bank not currently being used, automatically detect when all the coefficients have been written and then automatically switch banks during the vertical blanking interval in the television application.
1. A method for managing memory in a video signal processing device comprising:
processing a video signal using a first bank of video filter coefficients;
detecting a change in a video display format of said video signal;
writing video filter coefficient data corresponding to a second bank of video filter coefficients to a second memory in response to said change in said video display format;
disabling said first memory and said second memory;
switching an output from said first memory to said second memory in response to said writing step and a video blanking interval;
enabling said first memory and said second memory; and
processing said video signal using said second bank of video filter coefficients.
2. The method for managing memory of claim 1 , wherein said video blanking interval is a vertical video blanking interval.
3. The method for managing memory of claim 1 wherein said output is connected to a video filter.
4. The method for managing memory of claim 3 wherein said first memory and said second memory store video filter coefficient data.
5. The method for managing memory of claim 4 wherein said video filter coefficient data is the memory address data of video filler coefficients.
6. The method for managing memory of claim 1 wherein disabling said first memory and said second memory comprises the steps of disabling the read and write functions of said first memory and said second memory.
7. A method for changing video filter coefficients in a video signal processing device comprising:
detecting a change in a video display format of a video signal;
writing at least one address of a bank of video filter coefficients to a first memory;
disabling said first memory;
switching an output of a second memory to said first memory in response to a video blanking interval; and
enabling said first memory.
8. The method for changing video filter coefficients in a video signal processing device of claim 7 , wherein said video blanking interval is a vertical video blanking interval.
9. The method for changing video filter coefficients in a video signal processing device of claim 7 wherein said output is connected to a video filter.
10. The method for changing video filter coefficients in a video signal processing device of claim 9 , wherein said first memory and said second memory store video filter coefficient data.
11. An apparatus for selecting one of a plurality of video filter coefficients comprising:
a first memory for storing a first set of video filter data corresponding to a first bank of video filter coefficients;
a second memory for storing a second set of video filter data corresponding to a second bank of coefficients;
a processor for processing a video signal using said first set of video filter data, said processor further operative to detect a video display format of said video signal, for writing video filter data to said second memory in response to said change in said video display format, and for processing said video signal using said second set of video filter data;
a switch for selecting either said first memory or said second memory and coupling said selected memory to said processor; and
a bank switching device for detecting said processor writing video filter coefficient data, detecting a video blanking interval of said video signal and changing the state of said switch in response to detecting said writing of video coefficient data followed by said detecting of said video blanking interval.
12. The apparatus of claim 11 , wherein said video blanking interval is a vertical video blanking interval.
13. The apparatus of claim 11 wherein said first set of video filter data and said second set of video filter data are a plurality of memory address locations of video filter coefficients.
14. The apparatus of claim 11 wherein said first set of video filter data and said second set of video filter data are a plurality of video filter coefficients.
15. The apparatus of claim 11 wherein said switch is a multiplexer.
16. The apparatus of claim 11 wherein said apparatus is included within art integrated circuit.