AMBE-1000 Digital Voice Systems, Inc., AMBE-1000 Datasheet - Page 55

• Manufacturer Part Number: AMBE-1000
• Manufacturer: Digital Voice Systems, Inc.

6.5
6.6
6.6.1
6.6.2
The AMBE-1000 is not recommended for new designs.
Please refer to the AMBE-2000/2020 product line.
Standard Sleep Mode
Deep Sleep
There is a silence threshold value which is involved in the VAD algorithm. DVSI highly
recommends that the default value be used for this threshold.
describes how to access the silence threshold value.
The synthesis of a Comfort Noise frame by the decoder is not dependant on VAD being
enabled. The decoder will produce a comfort noise frame if either it receives an in-
band silence frame (produced only by an encoder with VAD enabled) or the Force
Decoder Silence field of Control_0 described in section 4.1.12 is set.
Dual Tone Multiple Frequency, Detection and Generation
The AMBE-1000™ Vocoder Chip is capable of detecting, transmitting, and synthesizing
DTMF tones. DTMF features are always enabled. Detection of a DTMF tone by the
encoder sets the DTMF Detected flag in the Status_0 field of the Framed Output Format
described in section 4.1.4.
information is placed in the Status_2 field described in section 4.1.6. Additionally, the
encoder passes the DTMF data in-band (within the regular voice data bits) so that
normal DTMF tones pass seamlessly from the encoder to the decoder for synthesis.
The decoder synthesizes a DTMF tone in response to reception of an in-band DTMF tone
frame or by the explicit use of Tone Generation Command Frames described in section
4.1.14.6.
Normal Power and Power Saving Modes
Power savings can be achieved during times of longer inactivity of the AMBE-1000™
chip by placing it into one of three available Low Power Modes. The chip can be placed
into low-power and stand-by modes via hardware or software Command Frames. In
low power modes the A/D-D/A port will be disabled, concurrently halting any
processing of voice frames in either direction.
selected, either a Wake Up Command Frame or a hardware reset on RESETN is
necessary to return the AMBE-1000™ to normal operation.
The standard sleep is the only low power mode that can be entered into either through
hardware or software. The AMBE-1000™ Chip can be placed into Standard Sleep mode
either by setting SLEEP_EN (pin 93) high, subject to the restrictions of section 6.1, or
through software by using a Command Frame with ID=0x04 as described in section
4.1.14.5.
SLEEP_EN should be tied high if you plan to configure the A/D-D/A chip from Standard
Sleep mode upon power-up or reset. Remember, in order to configure the A/D-D/A
chip using a Command Frame with ID=0x03 as described in section 4.1.14.4, the
AMBE-1000™ Chip must be placed into standard sleep mode.
To resume normal operation from standard sleep mode, send the AMBE-1000™ chip
Wake Up Command Frame as Described in section 4.1.14.7.
Deep Sleep provides the lowest power usage of the sleep modes, the only drawback to
this mode is the necessity of a hardware reset on RESETN (pin 39) to resume normal
operation. Deep sleep mode can only be entered using the Command Frame interface
as described in section 4.1.14.5.
The AMBE-1000 is not recommended for new designs.
Please refer to the AMBE-2000/2020 product line.
Visit us at www.dvsinc.com
Which DTMF tone is detected along with amplitude
page 55
Depending on the low power state
Section 4.1.14.3