AN2384 Freescale Semiconductor / Motorola, AN2384 Datasheet - Page 19

• Manufacturer Part Number: AN2384
• Description: Generic Tone Detection Using Teager-Kaiser Energy Operators on the StarCore SC140 Core
• Manufacturer: Freescale Semiconductor / Motorola

Freescale Semiconductor
Generic Tone Detection Using Teager-Kaiser Energy Operators on the StarCore SC140 Core, Rev. 1
pause_state = 1
Is duration long
(B)
Is digit = 0?
enough?
The sum of interruptions
is a non-valid signal
Is previous_digit
an interruption?
Is new_digit
previous_digit?
Is interruption
assigned to digit
YES
YES
new_digit
too long?
YES
YES
YES
Figure 11. Digit Processing Block Diagram
NO
NO
NO
NO
NO
duration increased
duration added to
Total interruption
previous_digit
digit duration.
Is pause_state = 1?
Is digit long enough
Store Key Value
to be a key?
(A)
Initialize Variables at
the Beginning of the
YES
YES
Program
Process Next Sample
Durations are merged
Is previous_digit
NO
= digit?
NO
YES
(A)
DTMF Detector on StarCore
previous_digit data
is assigned to digit
NO
of previous_digit
Step 2: Analysis
Step1: Analysis
of digit
(B)
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