Neo 1973 audio subsystem

Revision as of 17:17, 23 January 2007

Voice Calls

using phone-internal microphone and speaker

This is teh default case.

• microphone path
  • input: built in microphone attached to wolfson MIC2/MIC2N
  • routed from wolfson MIC2/MIC2N to MONO1/MONO2
  • arrives at GSM Modem input MICIP/MICIN
• speaker path
  • input: GSM Modem attached to wolfson RXN/RXP
  • routed from wolfson RXN/RXP to ROUT1/LOUT1
  • arrives on LM4857 RIN/LIN
  • routed on LM4856 to EP+/EP-

using analog (4pin 2.5mm) headset

This is also a quite common case, since we ship the headset with the phone

Headset Detection is done via GPIO on S3C2410

• microphone path
  • input: headset mic vial HS_MIC attached to wolfson MIC1
  • routed from wolfson MIC1 to MONO1/MONO2
  • arrives at GSM Modem input MICIP/MICIN
• speaker path
  • input: GSM Modem attached to wolfson RXN/RXP
  • routed from wolfson RXN/RXP to ROUT1/LOUT1
  • arrives on LM4857 RIN/LIN
  • routed on LM4856 to LHP/RHP

using bluetooth headset

Headset detection via software

• microphone path
  • input: from bluetooth via PCM interface to wolfson
  • wolfson: DAC
  • wolfson routes analog signal to MONO1/MONO2
  • arrives at GSM Modem input MICIP/MICIN
• speaker path
  • input: GSM Modem attached to wolfson RXN/RXP
  • wolfson: ADC
  • wolfson: routes digital signal to PCM
  • arrives on bluetooth chip via PCM

Multimedia

sound playback to speakers

This is an important mode since it is also required for ringtone playback

• speaker path
  • input: from S3C2410 via IIS interface to wolfson
  • wolfson: DAC
  • wolfson: route to ROUT1/LOUT1
  • LM4857: arrives on RIN/LIN
  • LM4857: route to LLS+-/RLS+-

sound playback to headphone

• speaker path
  • input: from S3C2410 via IIS interface to wolfson
  • wolfson: DAC
  • wolfson: route to ROUT1/LOUT1
  • LM4857: arrives on RIN/LIN
  • routed on LM4856 to LHP/RHP

sound playback via A2DP

FIXME

voice recording

This is mainly used to record notes

• microphone path
  • can be from built-in mic
  • or from headset
  • or bluetooth headset

Call recording

This is a nice wishlist item. The user should be able to receive the full-duplex audio from the wolfson codec, and record it using the S3C2410 IIS.

recording

FIXME

playback

FIXME

Important issues/pitfalls

Ringtone while hedset playbac

If the user is listening to music on the headset, do we want to mix the ringtones only into the headset audio, or actually interrupt and play it on the speaker?