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Codec data lines:

|| '''Pin Name''' || '''Direction'''|| '''Description ''' ||
|| M_CLKIN || In || Master Clock Input ||
|| M_SCK || Out || Serial Clock Output ||
|| M_CNTRL_SIN || In || Control Input ||
|| M_STROBE || Out || Serial Frame Sync ||
|| M_TXSIN || In || Serial Transmit Data ||
|| M_RXOUT || Out || Serial Receive Data ||

CPU/DSP McBSP1 data lines:

|| '''Pin Name''' || '''Direction'''|| '''Description ''' ||
|| CLKS || In || Clock input ||
|| DR || In || Data input ||
|| DX || Out || Data output ||
|| CLKX || In/Out || Bit clock ||
|| FSX || In/Out || Frame synchronization ||

4 data lines are switched between the modem and the processor by bitmask 0x2000 (AMS_DELTA_LATCH2_MODEM_CODEC) of latch2.

The main piece of the puzzle remaining on the E3 is sound.

The handset and internal mic/speaker are connected to the Conexant CX20442-11 voice codec. This is part of the modem chipset and a datasheet has proved impossible to find. Easy enough to find pinouts, but no actual description of the data that goes over the bus.

It is possible to use the modem to output/record sound from the various devices. vm from [http://mgetty.greenie.net/ mgetty] will do this. You need a voice.conf that looks a bit like:

program vm
  speed 115200
  forceV253 on
  voice_devices ttyS1

Full duplex doesn't successfully work based on tests so far.

Mark Underwood has written an ALSA driver that takes advantage of the fact the codec can be switched to talk to McBSP1 on the processor. This currently only outputs to the handset and records from the internal mic.

Codec data lines:

Pin Name

Direction

Description

M_CLKIN

In

Master Clock Input

M_SCK

Out

Serial Clock Output

M_CNTRL_SIN

In

Control Input

M_STROBE

Out

Serial Frame Sync

M_TXSIN

In

Serial Transmit Data

M_RXOUT

Out

Serial Receive Data

CPU/DSP McBSP1 data lines:

Pin Name

Direction

Description

CLKS

In

Clock input

DR

In

Data input

DX

Out

Data output

CLKX

In/Out

Bit clock

FSX

In/Out

Frame synchronization

4 data lines are switched between the modem and the processor by bitmask 0x2000 (AMS_DELTA_LATCH2_MODEM_CODEC) of latch2.

TheEarthWiki: E3_Sound (last edited 2008-02-19 15:39:12 by localhost)