FreeCalypso > hg > freecalypso-reveng
comparison compal/audio/tfc139-headset-entry @ 378:82fb5a70c9fd
compal/audio: results of simple experiments
| author | Mychaela Falconia <falcon@freecalypso.org> |
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| date | Sat, 09 Oct 2021 23:20:00 +0000 |
| parents | |
| children |
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| 377:34490934ff02 | 378:82fb5a70c9fd |
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| 1 The following results have been obtained by connecting to a C139 phone via the | |
| 2 headset jack, switching to "Trace On" via the **16379# hidden menu, breaking in | |
| 3 with tfc139, then running the new tfc139-audio-dump command in fc-loadtool: | |
| 4 | |
| 5 d_aec_ctrl: 0x03C7 | |
| 6 New AEC params: 0x0001 0x0014 0x4CCC 0x59AD 0x7500 0x0000 0x1000 0x1000 | |
| 7 | |
| 8 Uplink FIR coefficients: | |
| 9 | |
| 10 0x4000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 | |
| 11 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 | |
| 12 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 | |
| 13 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 | |
| 14 | |
| 15 Downlink FIR coefficients: | |
| 16 | |
| 17 0x7FFF 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 | |
| 18 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 | |
| 19 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 | |
| 20 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 0x0000 | |
| 21 | |
| 22 VBCTRL1: 0x004 | |
| 23 VBCTRL2: 0x007 | |
| 24 VBPOP: 0x004 | |
| 25 VBUCTRL: 0x1B2 | |
| 26 VBDCTRL: 0x069 | |
| 27 | |
| 28 Commentary: the values read out of VBCTRL1 and VBCTRL2 registers are consistent | |
| 29 with the headset audio channel being selected for both input and output, leading | |
| 30 to the suspicion that the firmware probably switched the audio path to headset | |
| 31 mode even though the **16379# hidden menu selection was set to "Trace On". The | |
| 32 Mother's primary interest here is to see the official C139 fw settings for the | |
| 33 handheld audio mode (built-in earpiece and mic) rather than the headset mode, | |
| 34 but it now appears that such capture won't be possible except maybe by | |
| 35 connecting to the production test pads inside the battery compartment, | |
| 36 bypassing the headset jack. | |
| 37 | |
| 38 Looking at what appears to be C139 headset mode audio config, we see that | |
| 39 HSMICBIAS voltage is set to 2.0 V, the uplink gain is set to 8 dB, and the | |
| 40 sidetone level is set to -23 dB: we get this info from the MICBIAS bit in | |
| 41 VBCTRL1 and the VBUCTRL setting. Decoding VBDCTRL, we see that the volume | |
| 42 control is set to -6 dB and the PGA gain is set to 3 dB. However, these | |
| 43 VBDCTRL settings don't tell us much: see the volume-ctrl article. | |
| 44 | |
| 45 Also note the FIR coefficient oddity: no frequency curve-transforming FIR | |
| 46 filters are being set up, neither UL nor DL, but DL FIR coefficient 0 is set to | |
| 47 0x7FFF instead of 0x4000. This oddity means that Calypso DL FIR block is | |
| 48 producing a 6 dB gain (doubling of the samples) purely on the digital side, | |
| 49 before DL audio passes to the ABB - certainly a noteworthy hack. |