I have build filter using FIR compiler. It is filtering the input quite well. I used COE generated from Matlab. I have two problems.
1- filter latency is 39 cycles. I am getting my RDY signal high after around 39 cycles. But RFD gets high after 251 cycles? I don't understand , if filter is giving me RDY signal high then according to FIR compiler datasheet figure of MAC multiplier timings, i should get RFD as soon as RDY gets high. I have tried both systolic and transpose MAC. I am attaching the figures from chip-scope.
ZOOM-IN of ND-RFD
ZOOM-IN of RDY
ZOOM-OUT including two RFDs
I want to get RFD as soon as my filter output is ready. Any clue !
2.All is fine. filtering is good. I am using filter range from 900hz-3300hz. I am getting TICK like sound after some 500msec. I saw it on oscilloscope it is some type of clipped signal containing 5-6 cycles of not any specific frequency. the signal is looking more like square wave due to clipping. I am getting that TICK sound even if I did not attach LINE IN cable (from which data is fed to filter input through CODEC). But if I programmed the input of filter to '0' in verilog, I get nothing. Tick sound is also removed now . Filter is generating tick sound in any other condition, What is this? am I getting overflow some where?
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hassan_3md
I have build filter using FIR compiler. It is filtering the input quite well. I used COE generated from Matlab. I have two problems.
1- filter latency is 39 cycles. I am getting my RDY signal high after around 39 cycles. But RFD gets high after 251 cycles? I don't understand , if filter is giving me RDY signal high then according to FIR compiler datasheet figure of MAC multiplier timings, i should get RFD as soon as RDY gets high. I have tried both systolic and transpose MAC. I am attaching the figures from chip-scope.
ZOOM-IN of ND-RFD
ZOOM-IN of RDY
ZOOM-OUT including two RFDs
I want to get RFD as soon as my filter output is ready. Any clue !
2.All is fine. filtering is good. I am using filter range from 900hz-3300hz. I am getting TICK like sound after some 500msec. I saw it on oscilloscope it is some type of clipped signal containing 5-6 cycles of not any specific frequency. the signal is looking more like square wave due to clipping. I am getting that TICK sound even if I did not attach LINE IN cable (from which data is fed to filter input through CODEC). But if I programmed the input of filter to '0' in verilog, I get nothing. Tick sound is also removed now . Filter is generating tick sound in any other condition, What is this? am I getting overflow some where?
Thanks
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