Embedded DSP: Mini Project
- Realization of a simple Digital Voice Recorder
Labaratory Project: Real-Time Signal Processing with SHARC 21061
Objectives
• To become familiar with Visual DSP++ and the SHARC-EZ-KIT-Lite.
• Learn to program and use a control flow.
• Learn how to use interrupt driven I/O.
• Learn how to use I/O by polling mode.
• Learn to use Codec functions
The Voice Recorder should be able to store 3 records which means that 3
buffers are necessary.
• Two records use a DM-data buffer with max. 5600 data samples.
• One record use a data buffer in the PM-memory.
• The sampling rate should be 5.512 KHz (5512 samples/second).
Data recording by FLAG1:
• Each record (1,2,3) automatically uses the corresponding DM-buffer or PMbuffer
(1,2,3).
• The record in process automatically stops when the buffer end is reached.
• A record should be started with the pushbutton FLAG1, which means that FLAG1
is set as an input (refer to internal SHARC register mode2).
– How to modify the register mode2 by C or Assembler ?
– How to read the Input switch FLAG1 by polling mode ?
– How to debounce the switch by software ?
• The record should be indicated by LED FLAG3, which means that FLAG3 is set
as an output (refer to internal SHARC register mode2).
– How to modify the register mode2 by C or Assembler ?
– How to set the FLAG3 output to a certain visble time (blink...) ?
Data recording by FLAG1:
Indications
• Start of record should be indicated by setting the LED/FLAG3 to -ON-.
• End of record should be indicated by clearing the LED/FLAG3 to -OFF-.
– How to set the FLAG3 output during record ?
Optical indication of a record :
Play back by FLAG2:
• Each record (1,2,3) should be started for play back by pushbutton FLAG2, which
means that FLAG2 is set as an input.
– How to modify the register mode2 by C or Assembler ?
– How to read the Input switch FLAG2 by polling mode ?
– How to debounce the switch by software ?
• The start and the end of a play back should be indicated by LED FLAG3, which
means that FLAG3 is set to output (refer to internal SHARC register mode2).
– How to modify the register mode2 by C or Assembler ?
– How to set the FLAG3 output to a certain visble time (blink...) ?
• Playing back of a selected record (1,2,3) should be indicated by a blink mode of
LED/FLAG3.
– How to modify the register mode2 by C or Assembler ?
– How to set the FLAG3 output to a certain visble time (blink...) ?
Optical indication of Play back:
Selecting a buffer for recording or play-back mode:
• A consecutive record should be selected by the pushbutton IRQ1. At the start of
the programm the first buffer is selected by default.
• The pushbutton IRQ1 is linked to the external interrupt IRQ1 of the SHARC.
• By pressing this pushbutton the next buffer should be automatically selected. By
each pressing of the pushbutton the pointer for the next buffer should
recirculate according to the count of the used number of records(1,2,3,1,2,3,...).
– How to use the IRQ1 by C or Assembler ?
– How write and implement an interrupt service routine ?
Automatic record controlled by a programmed sound-level
• Controlled by a software switch
• If used the FLAG1 enables the record.
• The record will be started by crossing over the programmed threshold-level.

download full report
http://rw4.cs.uni-sb.de/~kaestner/es0203/lecthr07.pdf