MUNI
F I
PA221: Filter and Signal Tap - Part 2
Template
Audio
KEY[0]
SW[1:0]
SW[3]
w04_filter_signaltap.v
Reset generator
sequential process
rst
E E K 0 5: FILTER
audio module.v
Input MUX
LFSR generator noise		
	>	f
	c	^ ->
		J > <
Square generator "tone"	>	
		
Filter bypass
Mic input
Audio controller
- audio_codec
- clock_generator
- audio_and_video_config
ian.kral@fi.muni.cz
Audio    Codec IC * WM8731
Audio Codec
Audio codec	
writedatajeft writedata_right write	write_ready
read reset > elk	readdatajeft readdata_right read_ready
W E E K 0 5
FILTER
ian.kral@fi.muni.cz
Assignment
Complete Signal Tap Tasks (previous week)
- Examine all internal signal (previous slide) of Audio Codec
- Determine sampling frequency of readdatajeft and readdata_right
signals
- Set input mux to SW[1:0] = 2'b01 and capture at least one period of square wave signal in Signal Tap
4
Assignment
Instantiate your fir_50k into signal chain
- Examine the filter effect on audio signal
- Noise only
- Square wave only
- Noise + square wave
Optional: Observe the audio input in Signal Tap
- Connect the mic
- Set storage qualifier to read = 1'b1
- Observe the audio input as an analog waveform
i.cz 5
Filter Characteristics
Filter Characteristics
Filter Characteristics