Rainbow Electronics DS2165Q - Manual (Page 10)

DS2165/DS2165Q
041295 10/17
PCM AND ADPCM INPUT/OUTPUT
Since the organization of the input and output time slots
on the DS2165 does not depend on the algorithm se-
lected, it always assumes that PCM input and output will
be in 8-bit bytes and that ADPCM input and output will
be in 4-bit bytes. Figure 12 demonstrates how the
DS2165 handles the I/O for the three different algo- rithms. In the figure, it is assumed that channel X is in the
compression mode (CP/EX = 1) and channel Y is in the
expansion mode (CP/EX = 0). Also, it is assumed that
both the input and output time slots for both channels
are set to 0.
PCM AND ADPCM I/O EXAMPLE Figure 12
CLKX
FSX
XOUT (32KBPS)
XOUT (24KBPS)
XOUT (16KBPS)
CLKY
FSY
YIN (32KBPS)
YIN (24KBPS)
YIN (16KBPS)
YOUT
3–STATE
MSB LSB
XIN
MSB LSB
MSB LSB
MSB LSB
3-STATE
3-STATE
SEE NOTE 1
0 0
MSB LSB
MSB LSB
MSB LSB
MSB LSB
3-STATE
NOTE:
1. The bit after the LSB in the 24Kbps ADPCM output will only be a 1 when the DS2165 is operated in the soft-
ware mode and is programmed to perform 24Kbps compression; in all other configurations, it will be a 0.