Mobile telephone arranged to receive and transmit digital data samples of encoded speech

A communication data processing apparatus comprising processing means, read only memory and random access memory wherein;

• said processing means is configured to process communication data represented as digital samples in a first mode under the control of a first instruction set having first instructions or in a second mode under the control of a second instruction set having second instructions;
• each of said modes requires samples to be buffered and said first mode requires more buffering than said second mode;
• said first instructions are read from said read only memory and control the writing of data samples to said random access memory and the reading of stored data samples from said random access memory;
• operation is changed from said first mode to said second mode;
• samples are processed in accordance with said first mode resulting in data being read from said random access memory to provide vacated memory locations;
• and
• said second instruction set is written to said vacated memory locations in said random access memory while previously written samples continue to be processed by said first instruction set.

A mobile telephone arranged to receive and transmit digital data samples of encoded speech, comprising a processing means, read only memory and random access memory, wherein;

• said processing means is configured to process said sample of encoded speech in a half rate mode under the control of a first instruction set or in a full rate mode under the control of a second instruction set, wherein;
• each of said modes require samples to be buffered and said half rate mode requires more buffering than said full rate mode;
• said first instructions are read from read only memory and control the writing of data samples to said random access memory and a reading of stored data samples from said random access memory;
• operation is changed from said half rate mode to said full rate mode;
• samples are processed in accordance with said half rate mode resulting in data being read from said random access memory to provide vacated memory locations;
• and
• said second instruction set is written to said vacated memory locations into random access memory as previously written samples continue to be processed by said first instruction set.