Information processing device and mobile terminal

Abstract

There is a need to enable decompression of a speech signal even if no network synchronizing signal is output from a baseband processing portion. For this purpose, an information processing device includes a first serial interface. The first serial interface includes a notification signal generation circuit that generates a notification signal each time compressed data incorporated from the baseband processing portion reaches a predetermined data quantity, and notifies a speech processing portion of this state using the notification signal. The speech processing portion includes a synchronizing signal generation circuit that generates a network synchronizing signal based on the notification signal. A clock signal for PCM communication is generated based on the network synchronizing signal. A speech signal can be decompressed even if no network synchronizing signal is output from the baseband processing portion.

What is claimed is: 
     
         1 . An information processing device comprising:
 a first terminal capable of coupling with a baseband processing portion;   a second terminal capable of coupling with an audio processing portion;   a first serial interface capable of exchanging compressed data with the baseband processing portion coupled through the first terminal;   a speech processing portion capable of processing a speech signal incorporated by the first serial interface;   an oscillator;   a clock generator that generates a clock signal for PCM communication; and   a second serial interface that uses a clock signal generated from the clock generator to enable PCM communication between the audio processing portion coupled through the second terminal and the speech processing portion,   wherein the first serial interface includes a notification signal generation circuit that generates a notification signal each time compressed data incorporated from the baseband processing portion reaches a predetermined data quantity, and notifies the speech processing portion of this state using the notification signal,   wherein the speech processing portion includes a synchronizing signal generation circuit that generates a network synchronizing signal based on the notification signal,   wherein the clock generator generates the clock signal for PCM communication based on the network synchronizing signal generated from the synchronizing signal generation circuit, and   wherein the synchronizing signal generation circuit generates the network synchronizing signal based on a clock count number which is calculated based on a clock signal of the oscillator from a first generation of the notification signal to a second generation of the notification signal after the first generation.   
     
     
         2 . The information processing device according to  claim 1 ,
 wherein the first serial interface includes:   a buffer capable of outputting an incorporated signal based on a first-in first-out method; and   a pointer indicating a write position in the buffer, and   wherein the notification signal generation circuit includes:   a first threshold value register capable of setting a specified threshold value; and a first comparator that asserts the notification signal when a write position indicated by the pointer reaches a setting value in the first threshold value register.   
     
     
         3 . The information processing device according to  claim 2 ,
 wherein the synchronizing signal generation circuit includes:   a counter that counts the clock signal from the oscillator and is reset by the notification signal;   a second threshold value register capable of setting an upper limit and a lower limit;   a second comparator that determines whether a count value of the counter ranges between the upper limit and the lower limit of the second threshold value register;   a pulse information register that is supplied with pulse information based on a determination result from the second comparator; and   a pulse generator logic that generates the network synchronizing signal at a frequency corresponding to a setting value for the pulse information register.   
     
     
         4 . The information processing device according to  claim 3 ,
 wherein the speech processing portion includes a signal processing circuit that thins out a sample or embeds silence data when a count value in the counter does not range between an upper limit and a lower limit of the second threshold value register.   
     
     
         5 . The information processing device according to  claim 4 ,
 wherein the clock generator includes:   a selector that can select the network synchronizing signal output from the pulse generator logic and a synchronizing signal output from the baseband processing portion; and   a clock generation circuit that generates a synchronizing signal used for speech signal communication based on an output from the selector.   
     
     
         6 . The information processing device according to  claim 5 ,
 wherein the first terminal includes a third terminal for incorporating the synchronizing signal from the baseband processing portion; and   wherein the information processing device includes a switch capable of coupling the third terminal to a circuit other than the clock generator when the synchronizing signal is not incorporated from the baseband processing portion through the third terminal.   
     
     
         7 . A mobile terminal having a speech communication function, comprising:
 the information processing device according to  claim 5 ;   a baseband processing portion coupled to the information processing device; and   an audio processing portion coupled to the information processing device.