ml7084-001 Oki Semiconductor, ml7084-001 Datasheet - Page 182

• Manufacturer Part Number: ml7084-001
• Description: 4ch Voip Codec
• Manufacturer: Oki Semiconductor

Tone Disabler 1 (TD_RXDET1/TD_TXDET1)
The tone disabler 1 detects the phase inverted signal (ANSPM) of a 2100 Hz single tone signal input to the receive
and transmit sides of CH1, and also detectes the single tone signal (ANS). The tone disabler 1 can be activated
individually for reception and transmission using the control registers TD_RXDET1_EN and TD_TXDET1_EN.
When the phase inversion of an input signal is detected, “1” is set in the applicable control register at the time of tone
detection.
Also, if a silent state continues after detection, the tone disabler releases the signal (clears the applicable control
register to “0”). Figure 50 shows the detection timing of the tone disabler, using the transmit side as an example. The
following shows the various detection characteristics of this detector:
(Tone detection characteristics)
• Detection frequency
• Detection level
(Phase inversion detection characteristics)
• Detecting conditions
• Phase inversion characteristics:180 degrees
(Release characteristics)
• Detection level
• Release time
A. : TD_RXDET1 related
A-1. : TD_RXDET1 enable control register (TD_RXDET1_EN)
A-2. : TD_RXDET1 2100 Hz single tone detection status register (ANS_RXDET1)
A-3. : TD_RXDET1 2100 Hz phase inversion detection status register (ANSPM_RXDET1)
OKI Semiconductor
ANSPM_TXDET1
TD_TXDET1_EN
0 : Stop (Initial value)
1 : Operate
0 : Not detected (Initial value)
1 : Detected
0 : Not detected (Initial value)
1 : Detected
Tone detecting
ANS_TXDET1
Tone detecting
internal signal
internal signal
–33.5 dBm0 or less
100 ms
Figure 50 Tone disabler 1 Transmit Side Detection Timing
ON guard timer
: 2100 Hz
: –34 dBm0 or more
: Detects phase inversion once for each timing before and after a tone of 2100 Hz ,
for approx. 450±25 ms.
2100 Hz tone signal
OFF guard timer
ON guard timer
2100 Hz phase inverted signal
FEDL7224-001FULL-01
OFF guard timer
ML7224-001TC
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