PSB7238 SIEMENS [Siemens Semiconductor Group], PSB7238 Datasheet - Page 25

• Manufacturer Part Number: PSB7238
• Description: Joint Audio Decoder-Encoder - Multimode
• Manufacturer: SIEMENS [Siemens Semiconductor Group]

Channels
The following channels may be programmed on the IOM-2 interface: two receive audio
channels, two transmit audio channels, one monitor channel, two C/I channels, two
receive and two transmit HDLC channels:
Audio receive 1 and receive 2 channels
Audio transmit 1 and transmit 2 channels
Monitor channel
Two C/I channels
Two HDLC receive and transmit channels
The transfer of voice samples is performed with the help of an interrupt with repetition
rate 8 kHz derived from the FSC signal. A double-buffered register is provided for each
channel, accessible from the DSP and from the parallel host interface. The double
buffered register ensures that enough time is always provided for reading and writing
data before an overflow/underflow occurs, independent of the location of the time-slots.
Alternatively, the audio samples can be transferred between the DSP or Host and IOM-2
by using an interrupt generated when a programmable number (1
shifted out (number independent of the time-slot length on the line).
Outside the time-slots where transmission takes place the DU and DD lines are in high
impedance.
Semiconductor Group
25
Independently programmable on DD or
DU, with programmable locations (start
at bit 1
w.r.t. FSC
Programmable on DD(in)/DU(out) or
DD(out)/DU(in), with programmable
time-slot (3rd byte in multiplex 0,
after FSC
DD(out)/DU(in), with programmable
length (4 or 6 bits) and position (4th byte
in multiplex 0,
DU, with programmable locations (start
at bit 1
(1
Programmable on DD(in)/DU(out) or
Independently programmable on DD or
Interfaces and Memory Organization
256 bits) w.r.t. FSC
512) and lengths (1
512) and lengths
, 15) after FSC
Data Sheet 1998-07-01
32) of bits are
PSB 7238
32 bits)
, 15)