AMBE-1000 Digital Voice Systems, Inc., AMBE-1000 Datasheet - Page 53

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

6.
6.1
6.2
6.3
The AMBE-1000 is not recommended for new designs.
Please refer to the AMBE-2000/2020 product line.
BPS_SEL3
pin 3
0
0
0
1
1
0
0
0
1
1
1
1
1
0
0
Special Functions
Hardware vs. Software Selection Note
Many of the functions of the AMBE-1000™ can be accessed through both a hardware
and software interfaces to the device. The following hardware inputs, CH_SEL[2-0],
BPS_SEL[3-0], C_SEL[2-0], VAD_EN, ECHOCAN_EN, and SLEEP_EN, are only accessed
for input during the first 200 microseconds after a hardware reset on RESETN.
predictable operation these signals must remain stable over this time period. After this
initialization period the functions that these pins access can only be reconfigured
through the Command Frame interface described in sections 4.1.14.2 through
4.1.14.7. Changes on these pins after the 200 microseconds initialization period after
reset are ignored, unless another reset is performed.
Coding Rate Selection
The Voice coding rate as well as the FEC coding rate can be selected individually on the
AMBE-1000™. These rates are selected by using a Command frame as described in
section 4.1.14.2, or through hardware pins BPS_SEL[3-0] (pins 3, 4, 5 and 6) subject
to the restrictions in section 6.1.
preconfigured voice/FEC rates. The voice and FEC rates are individually configurable in
50 bit per second intervals. If rates other than those in Table 6-A are desired then the
Command Frame method of configuring the rates must be used.
Table 6-A Hardware Voice and FEC Rate Selection
Echo Cancellation
The AMBE-1000™ Vocoder Chip provides a 5 millisecond echo canceller that is suitable
for canceling the local echo caused by a 2-to-4 wire hybrid and can achieve echo
cancellation of approximately 30dB or more.
cancelled, so circuits should be designed to minimize non-linearities.
BPS_SEL2
The AMBE-1000 is not recommended for new designs.
pin 4
0
1
0
0
1
0
1
0
0
0
0
1
1
1
1
Please refer to the AMBE-2000/2020 product line.
BPS_SEL1
Visit us at www.dvsinc.com
pin 5
0
0
0
1
1
1
1
1
0
1
0
0
0
0
1
page 53
BPS_SEL0
pin 6
0
1
1
1
0
1
1
0
0
0
1
0
1
0
0
The four input pins BPS_SEL[3-0] give 15
Speech Rate
2400 bps
2350 bps
3600 bps
3350 bps
3750 bps
4800 bps
4550 bps
3600 bps
2550 bps
4150 bps
4400 bps
7750 bps
4650 bps
9600 bps
4850 bps
Only the linear portion of the echo is
FEC Rate
0
50 bps
0
250 bps
250 bps
0
250 bps
1200 bps
2250 bps
2250 bps
2800 bps
250 bps
3350 bps
0
4750 bps
Total Rate
2400 bps
3600 bps
4000 bps
4800 bps
6400 bps
7200 bps
8000 bps
9600 bps
For