Audio Control; Pcm Serial Interface - Nokia NSM-3 Series Technical Documentation Manual

NSM–3/3D
System Module

Audio control

PCM serial interface

The interface consists of following signals: a PCM codec master clock
(PCMDClk), a frame synchronization signal to DSP (PCMSClk), a codec
transmit data line (PCMTX) and a codec receive data line (PCMRX). The
COBBA–GJP generates the PCMDClk clock, which is supplied to DSP
SIO. The COBBA–GJP also generates the PCMSClk signal to DSP by di-
viding the PCMDClk. The PCMDClk frequency is 1.000 MHz and is gen-
erated by dividing the RFIClk 13 MHz by 13. The COBBA–GJP further di-
vides the PCMDClk by 125 to get a PCMSClk signal, 8.0 kHz.
PCMDClk
PCMSClk
PCMTxData
PCMRxData
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