Vocoder processing method, semiconductor device, and electronic device

Abstract

In a semiconductor device, a vocoder processing unit requests, after executing a first vocoder process being one of an encoding process and a decoding process and before executing a following second vocoder process being other one of the encoding process and the decoding process, a cache memory to prefetch first program data to be used for the second vocoder process from an external memory.

1 - 20 . (canceled) 
     
     
         21 . A semiconductor device, comprising:
 a signal processing unit including a prefetch request unit; and   a memory that reads data stored in an external memory via a bus,   wherein, after the signal processing unit executes an encoding process and before the signal processing unit executes a decoding process, the prefetch request unit requests the memory to prefetch program data for the decoding process from the external memory,   wherein, after the signal processing unit executes the decoding process and before the signal processing unit executes the encoding process, the prefetch request unit requests the memory to prefetch program data for the encoding process from the external memory, and   wherein the encoding process encodes a transmission voice signal and the decoding process decodes a reception voice signal.   
     
     
         22 . The semiconductor device according to  claim 21 , wherein, when the prefetch request unit prefetches the program data, the memory stores the program data from the external memory if the program data is absent in the memory. 
     
     
         23 . The semiconductor device according to  claim 21 , wherein the memory has a capacity of 100 kilobytes or less. 
     
     
         24 . The semiconductor device according to  claim 21 , further comprising a modem that executes a modulation process on the transmission voice signal after encoding, and that executes a demodulation process on the reception voice signal before decoding. 
     
     
         25 . An electronic device, comprising:
 a signal processing unit including a prefetch request unit;   a first memory; and   a second memory that reads decoding program data and encoding program data stored in an external memory via a bus,   wherein, after the signal processing unit executes an encoding process and before the signal processing unit executes a decoding process, the prefetch request unit requests the second memory to prefetch program data for the decoding process from the first memory,   wherein, after the signal processing unit executes the decoding process and before the signal processing unit executes the encoding process, the prefetch request unit request the second memory to prefetch program data for the encoding process from the first memory, and   wherein the encoding process encodes a transmission voice signal and the decoding process decodes a reception voice signal.   
     
     
         26 . The electronic device according to  claim 25 , wherein, when the prefetch request unit requests the second memory to prefetch the program data, the second memory prefetches the program data from the first memory if the program data is absent in the second memory. 
     
     
         27 . The electronic device according to  claim 25 , wherein the second memory has a capacity of 100 kilobytes or less. 
     
     
         28 . The electronic device according to  claim 25 , wherein the first memory is rewritable. 
     
     
         29 . The electronic device according to  claim 25 , wherein the first memory is a DRAM.