PCM4222

zx yang

Other Parts Discussed in Thread: PCM4222

We use the PCM4222 to sample the audio analog. Now I can't understand the function of OVFL(pins 37) and OVFR(pins 38). The Datasheet said "the overflow
indicators are forced high whenever a digital overflow is detected for a given channel."

Questions: 1. What the digital overflow means here？ Dose it mean the output of PCM data overflow?

2. When in case of overflow, what should I do in my program？Just flash a LED for indication? (I don't think so simple.)

Thanks!

over 7 years ago

0 Luis Fernando Rodriguez S. over 7 years ago

TI__Guru* 84915 points

Hi, zx yang,

Welcome to E2E and thank you for your interest in our products!

The OVFL and OVFR pins are overflow flag pins. This means that these pins are used to detect an overflow at the DACs. When the DAC data is above the full-scale voltage, these pins will be enabled depending of the DAC channel (OVFL for left channel and OVFR for right channel). These pins can be routed to a LED to indicate an overflow at the DAC channels.

For more information, please consult the Overflow indicators section of datasheet ( www.ti.com/.../pcm4222.pdf ).

Best regards,
Luis Fernando Rodríguez S.

0 zx yang over 7 years ago in reply to Luis Fernando Rodriguez S.

Prodigy 80 points

Thanks for your reply.

The PCM4222 is an ADC chip. So it indicates whether the input channel is above full-scale voltage or not, is it?

0 Luis Fernando Rodriguez S. over 7 years ago in reply to zx yang

TI__Guru* 84915 points

Hi, zx yang,

Effectively, OVFL and OVFR indicate if the input channel is above the full-scale voltage (OVFL for left channel and OVFR for right channel).

Best regards,
Luis Fernando Rodríguez S.

0 zx yang over 7 years ago in reply to Luis Fernando Rodriguez S.

Prodigy 80 points

Thank you very much.

0 zx yang over 7 years ago in reply to Luis Fernando Rodriguez S.

Prodigy 80 points

I have another question. If I power down the reset pin to reset the PCM4222 chip, after that do I need to reconfigure the mode pins such as filter, PCM output data format, word length, sampling rate and so on?

0 Luis Fernando Rodriguez S. over 7 years ago in reply to zx yang

TI__Guru* 84915 points

Hi, zx yang,

That's correct. When the reset pin is powered down, it is necessary to reconfigure the mode pins. All the PCM4222 functions will be set in default state after the reset is powered down. So, it is necessary to configure again the device.

Best regards,
Luis Fernando Rodríguez S.

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PCM4222