PEF2054 SIEMENS [Siemens Semiconductor Group], PEF2054 Datasheet - Page 166

• Manufacturer Part Number: PEF2054
• Description: ICs for Communications
• Manufacturer: SIEMENS [Siemens Semiconductor Group]

output time slot is later in time than the input time slot, the data received in frame N will
only be transmitted in frame N + 1 or even N + 2 (see figure 60 b)) and figure 60 c)).
Figure 60
Switching Delays
5.4.4
When a channel is switched from an input time slot (e.g. from the PCM interface) to an
output time slot (e.g. to the CFI), it is sometimes useful to know the frame delay
introduced by this connection. This is of prime importance for example if channels having
a bandwidth of n
the EPIC. If all 6 time slots of an H0 channel are not submitted to the same frame delay,
time slot integrity is no longer maintained.
Since the EPIC has only a one frame buffer, the switching delay depends mainly on the
location of the output time slot with respect to the input time slot. If there is “enough” time
between the two locations, the EPIC switches the input data to the output data within the
same frame (see figure 60 a)). If the time between the two locations is too small or if the
Semiconductor Group
a) Switching Delay : 0 Frames
Input Frame
Output Frame
b) Switching Delay : 1 Frames
Input Frame
Output Frame
c) Switching Delay : 2 Frames
Input Frame
Output Frame
Switching Delays
64 kbit/s (e.g. H0 channels: 6
N
N
N
N
N
N
166
N + 1
N + 1
N + 1
N + 1
N + 1
N + 1
64 = 384 kbit/s) shall be switched by
N + 2
N + 2
N + 2
N + 2
N + 2
N + 2
+
Application Hints
ITD08075
PEB 2055
PEF 2055