PEB20571 INFINEON [Infineon Technologies AG], PEB20571 Datasheet - Page 99

• Manufacturer Part Number: PEB20571
• Description: ICs for Communications
• Manufacturer: INFINEON [Infineon Technologies AG]

4.3.2
Figure 4-3
4.3.2.1
The main task of the IOMU is the serial-to-parallel conversion of incoming IOM-2 data to
a parallel data format which is directly read by the DSP. This access is required for the
DSP to perform switching of B-channels, extraction of D-channels, and layer-1 control
via the IOM-2 C/I and Monitor channels.
The data conversion in the IOMU is done by frame-wise swapping based on a circular
buffer structure. During each 8 kHz frame, one buffer is assigned to the IOMU (I-buffer),
and the other one to the DSP (D-buffer). At the end of every frame, the buffers are
swapped.
4.3.2.2
The logical partitioning of each frame buffer into input and output blocks is determined
according to the requested data rate as shown in the table below.
The address of each data byte in the I-buffer output blocks by the DSP must be selected
according to the IOM port and time slot index, in which it should be transmitted.
Preliminary Data Sheet
IOM-2 Interface
D.C/I M
D.C/I M
B1
B1
IOM-2000
Interface
B2
B2
M D,C/I
M D,C/I
B2
B2
DRDY
IOMU Functional and Operational Description
Frame-Wise Buffer Swapping
I-buffer Logical Structure
DCL
FSC
B1
B1
IOMU Integration in DELIC
DU0
DU1
DD1
DD0
DELIC
TRANSIU
IOMU
4-15
CLOCKS
SWITCHING
DSP
Functional Description
HDLCU
PCMU
PEB 20571
PCM
Interface
DELIC
2003-08