Pipelined systolic finite impulse response filter
First Claim
1. A systolic FIR filter circuit comprising:
- a plurality of multipliers, each respective one of said multipliers having a respective coefficient input, a respective sample input, and a respective multiplier output;
a plurality of sample pre-adders, each respective one of said sample pre-adders connected to a sample input of a respective one of said multipliers;
an output cascade adder chain comprising a respective output adder connected to a respective multiplier output of each respective one of said multipliers, each respective output adder having a first input receiving said respective multiplier output, and, except for a first output adder in said output cascade adder chain, having a second input receiving an output of a previous one of said output adders, said output cascade adder chain further comprising a selectable number of output delays between adjacent ones of said output adders; and
an input sample chain having a first leg and a second leg;
wherein;
each respective one of said sample pre-adders receives a respective input from a respective sample point in said first leg and a respective input from a respective sample point said second leg;
said input sample chain has, between adjacent sample points in at least one of said legs, a selectable number of sample delays related to said selectable number of output delays; and
connections of inputs from said input sample chain to said sample pre-adders are adjusted to account for said selectable number.
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Abstract
A systolic FIR filter circuit includes a plurality of multipliers, a plurality of sample pre-adders, each respective one of the sample pre-adders connected to a sample input of a respective multiplier, and an output cascade adder chain including a respective output adder connected to a respective multiplier. The output cascade adder chain includes a selectable number of delays between adjacent output adders. An input sample chain has a first leg and a second leg. Each respective one of the sample pre-adders receives a respective input from the first leg and a respective input from the second leg. The input sample chain has, between adjacent sample points in at least one of the legs, a selectable number of sample delays related to the selectable number of output delays. Connections of inputs from the input sample chain to the sample pre-adders are adjusted to account for the selectable number.
236 Citations
28 Claims
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1. A systolic FIR filter circuit comprising:
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a plurality of multipliers, each respective one of said multipliers having a respective coefficient input, a respective sample input, and a respective multiplier output; a plurality of sample pre-adders, each respective one of said sample pre-adders connected to a sample input of a respective one of said multipliers; an output cascade adder chain comprising a respective output adder connected to a respective multiplier output of each respective one of said multipliers, each respective output adder having a first input receiving said respective multiplier output, and, except for a first output adder in said output cascade adder chain, having a second input receiving an output of a previous one of said output adders, said output cascade adder chain further comprising a selectable number of output delays between adjacent ones of said output adders; and an input sample chain having a first leg and a second leg;
wherein;each respective one of said sample pre-adders receives a respective input from a respective sample point in said first leg and a respective input from a respective sample point said second leg; said input sample chain has, between adjacent sample points in at least one of said legs, a selectable number of sample delays related to said selectable number of output delays; and connections of inputs from said input sample chain to said sample pre-adders are adjusted to account for said selectable number. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A programmable integrated circuit device configured as a systolic FIR filter circuit, said configured programmable integrated circuit device comprising:
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a plurality of multipliers, each respective one of said multipliers having a respective coefficient input, a respective sample input, and a respective multiplier output; a plurality of sample pre-adders, each respective one of said sample pre-adders connected to a sample input of a respective one of said multipliers; an output cascade adder chain comprising a respective output adder connected to the respective multiplier output of each respective one of said multipliers, each respective output adder having a first input receiving said respective multiplier output, and, except for a first output adder in said output cascade adder chain, having a second input receiving an output of a previous one of said output adders, said an output cascade adder chain further comprising a selectable number of output delays between adjacent ones of said output adders; and an input sample chain having a first leg and a second leg;
wherein;each respective one of said sample pre-adders receives a respective input from a respective sample point in said first leg and a respective input from a respective sample point in said second leg; said input sample chain has, between adjacent sample points in at least one of said legs, a selectable number of sample delays related to said selectable number of output delays; said sample delays are implemented by on-board memories of said programmable integrated circuit device; and said selectable number of sample delays are adjusted relative to said selectable number of output delays to maintain timing in said systolic FIR filter circuit. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15)
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16. A method of configuring a programmable integrated circuit device as a systolic FIR filter circuit, said method comprising:
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configuring a plurality of multipliers with, each respective one of said multipliers having a respective coefficient input, a respective sample input, and a respective multiplier output; configuring a plurality of sample pre-adders, by connecting each respective one of said sample pre-adders to a sample input of a respective one of said multipliers; configuring an output cascade adder chain by connecting a respective output adder to the respective multiplier output of each respective one of said multipliers, each respective output adder having a first input receiving said respective multiplier output, and, except for a first output adder in said output cascade adder chain, having a second input receiving an output of a previous one of said output adders, and further configuring a selectable number of output delays between adjacent ones of said output adders; and configuring an input sample chain having a first leg and a second leg;
wherein;each respective one of said sample pre-adders receives a respective input from a respective sample point in said first leg and a respective input from a respective sample point in said second leg; and said input sample chain has, between adjacent sample points in at least one of said legs, a selectable number of sample delays related to said selectable number of output delays;
said method further comprising;implementing said sample delays using on-board memories of said programmable integrated circuit device; and adjusting said selectable number of sample delays relative to said selectable number of output delays to maintain timing in said systolic FIR filter circuit. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23)
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24. A systolic FIR filter circuit comprising:
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an input sample chain having a first leg and a second leg; and a plurality of taps, wherein for each of said taps, a sample from a respective sample point in said first leg is combined with a sample from a respective sample point in said second leg;
wherein;said input sample chain has an input at a point common to both said legs; and for each of said taps, said respective sample point in said first leg and said respective sample point in said second leg are separated from said common point by an identical number of sample points. - View Dependent Claims (25, 26, 27, 28)
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Specification