AMBE-1000 Digital Voice Systems, Inc., AMBE-1000 Datasheet - Page 27

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

The AMBE-1000 is not recommended for new designs.
Please refer to the AMBE-2000/2020 product line.
3.4
Serial Mode
The signals in Table 3-G make up the serial channel interface. The serial channel mode
transfers data in and out of the AMBE-1000™ using 16 bit words on the two data lines
CHS_DI and CHS_DO.
The selection of the framed or unframed format of this data
is made using information in Table 3-A.
As described in section 4.1, the framed format consists of 272 bits being output from
the encoder and input to the decoder over each 20 milliseconds. This implies that in
serial mode, each 20 milliseconds the hardware interfacing to the AMBE-1000 will have
to perform 17 reads and 17 writes, each of 16 bits, regardless of the voice coding rate.
In unframed mode, the number of reads and writes is variable depending on the voice
coding bit rate selected and the number of voice data bits per word as seen in Table
In unframed mode, which is only selectable in passive mode, the minimum
3-A.
number of reads and writes per frame would be 12 {(minimum bit rate)
(maximum
voice data bits per word)
(50 frames per second) = (2400)
(4)
(50) = 12 }. The
maximum number of reads and writes of 192 can be similarly calculated { (9600)
(1)
(50) = 192 }.
The limitations on how quickly the data can be transferred in and out of the AMBE-
1000™ during serial mode are governed by the requirement to allow CHS_IBF and
CHS_OBE to return low after the input buffer has been written to or the output buffer
has been read. See sections 3.4.2 and 3.4.3 for more details.
page 27
The AMBE-1000 is not recommended for new designs.
Please refer to the AMBE-2000/2020 product line.
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