Xerox FaxCentre F110, Service Manual

Page: 182 / 204

General Procedures / Information
6-96 12/04 FaxCentre F110
GP 44 Connection of the Codec to DC2
Low End
For low-end version, the codec is directly connected to the Digicolor2. The modem function is re-
alised in firmware. The codec is a STLC7550 codec from STM.
Figure 1
The codec is clocked by a 18,432MHz crystal.
To provide a proper clock to the serial link, the codec must be configured as a slave, providing the
SCLK. For this pins MCM is tied to 1 and M/S to 0. The bus clock SCLK is connected to the
AC_CLKEXT of the Digicolor2 and the output AC_SCLK or the Digicolor is left unconnected.
The register Config2 of the codec interface block should be programmed as follow:
• Bit 7-6: extclk_md[1:0]= 10
• Bit 5: tr_extclk = 0
• Bit 4: tr_nbaud = 1
With this configuration, the codec block uses the SCLK coming form the codec as its internal clock
and the SCLK coming out of Digicolor2 is equal to the input AC_CLKEXT.
High end
The chip modem is an Agere data pump (DP2Vxx) + CODEC (1034C). V32 to V90 data pump can
be used. The data pump is supervised by digicolor2 on peripheral bus.
The line interface can manage an external telephone.
STLC7550
Din
Dout
FS
SCLK
Reset
AC_TX
AC_RX
AC_FS
AC_SCLK
AC_CLKEXT
GP_C3
Out+
Out-
In+
In-
LIU
XTALIN
XTALOUT
PI_Line_Sync(veille) PWRDWN