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@ -136,10 +136,11 @@ IOBUF PORT "adc_sclk" PULLMODE=UP IO_TYPE=LVCMOS33 DRIVE=4;
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## Audio 4-bit DAC "analog", "gpio" sheet
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## Audio 4-bit DAC "analog", "gpio" sheet
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# 4-bit mode can drive down to 75 ohm load impedance.
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# 4-bit mode can drive down to 75 ohm load impedance.
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# Lower impedance leads to IO overload,
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# Lower impedance leads to IO overload,
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# FPGA will stop working and need reboot.
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# FPGA will stop working and need reboot.
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# For standard 17 ohm earphones:
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# For standard 16 ohm earphones on PCB v1.7:
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# use bits 2,3 as input (High-Z) and drive only bits 0,1.
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# use bits 2,3 as input (High-Z) and drive only bits 0,1.
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# PCB v2.1.2 and higher can use full 4 bits and 16 mA drive for 16 ohm earphones.
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LOCATE COMP "audio_l[3]" SITE "B3"; # JACK TIP (left audio)
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LOCATE COMP "audio_l[3]" SITE "B3"; # JACK TIP (left audio)
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LOCATE COMP "audio_l[2]" SITE "C3";
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LOCATE COMP "audio_l[2]" SITE "C3";
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LOCATE COMP "audio_l[1]" SITE "D3";
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LOCATE COMP "audio_l[1]" SITE "D3";
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