Feedback Control
Adaptive Feedback Control (AFC)
Although feedback should be prevented through the use of acoustic echo cancellation, it is still possible that the onset of feedback could defeat the acoustic echo canceller.
Typical applications include hands-free communication systems, public address systems, and hearing aids.
Features List
- Functions are C-callable
- Designed for Multi-channel operation
Availability
Platforms
Texas Instruments – TI TMS320C6000 C64x, C64x+, C674x | C66x
Texas Instruments – TI TMS320C5000 C55x
ADT AFC is available on the above Platforms: Other configurations are available upon request.
Specifications
Note: All CPU usage given in MIPS (also known as MCPS or MHz)
AFC C64x+ / C66x / C674x
CPU UTILIZATION & MEMORY REQUIREMENTSAll Memory usage is given in units of byte.
| AFC | Sampling Rate | MIPS (Peak) | Program Memory | Data Mem | Per Channel Data Mem |
| AFC_ADT_run | 8000 | 32 | 5216 | 4854 | 1676 |
| AFC_ADT_run | 16000 | 64 | 5216 | 5190 | 2544 |
| AFC_ADT_run | 44100 | 339 | 5216 | 6254 | 5244 |
| AFC_ADT_run | 48000 | 397 | 5216 | 6414 | 5676 |
AFC C64x
CPU UTILIZATION & MEMORY REQUIREMENTSAll Memory usage is given in units of byte.
| AFC | Sampling Rate | MIPS (Peak) | Program Memory | Data Mem | Per Channel Data Mem |
| AFC_ADT_run | 8000 | 22 | 5216 | 4854 | 1676 |
| AFC_ADT_run | 16000 | 61 | 5216 | 5190 | 2544 |
| AFC_ADT_run | 44100 | 333 | 5216 | 6254 | 5244 |
| AFC_ADT_run | 48000 | 364 | 5216 | 6414 | 5676 |
AFC C55x
CPU UTILIZATION & MEMORY REQUIREMENTSAll Memory usage is given in units of byte.
| AFC | Sampling Rate | MIPS (Peak) | Program Memory | Data Mem | Per Channel Data Mem |
| AFC_ADT_run | 8000 | 67 | 2339 | 5542 | 3504 |
Description
In many acoustic applications, the presence of feedback can cause a resonance to occur. Whether or not the resonance occurs as well as the frequency of the resonance depends upon many variables: is a function of gain/loss, acoustic reflections, room size, and system delay.
Adaptive Digital’s Adaptive Feedback Control algorithm analyzes an input signal, determines whether or not there is a resonance, and eliminates the resonance while minimizing the effect on the desired signal.
Function API's
API function call summary
AFC_ADT_init(. . .)
AFC_ADT_initObj(. . .)
AFC_ADT_run(. . .)