pef20550 Infineon Technologies Corporation, pef20550 Datasheet - Page 206

• Manufacturer Part Number: pef20550
• Description: Extended Line Card Interface Controller Elic
• Manufacturer: Infineon Technologies Corporation

The PCM interface shall be clocked with a PDC having the same frequency as the data
rate i.e. 2048 kHz. Since the rising edge of PFS occurs at the same time as the rising
edge of PDC, it is recommended to select the falling PDC edge for sampling the PFS
signal (PMOD:PSM0 = 0). In this case the 1st bit of internal framing structure (according
to figure 62) will represent timeslot 0, bit 6 (2nd bit) of the external frame (according to
figure 60). The values to be programmed to the POFD, POFD and PCSR can now be
determined as follows:
With BND = BNU = 2 and BPF = 256:
POFD = OFD9 … 2 = (BND – 17 + BPF)
POFU = OFU9 … 2 = (BNU + 23)
With URE = 1 and DRE = 0:
PCSR = 01
2) In PCM mode 1, with a frame consisting of 48 timeslots, the following timing
Figure 63
Timing for PCM Frame Offset of Example 2
Semiconductor Group
PFS
PDC
TxD#
Required
Time-Slot/Bit
Offset in
Upstream
Direction
Required
Time-Slot/Bit
Offset in
Downstream
Direction
RxD#
relationship between the framing signal and the data signals is required:
H
Bit 3
381
Bit 7
1
Bit 2
382
0
Bit 6
2
1
Time-Slot 47
Start of Internal Frame
Bit 1
BNU
383
mod BPF
Bit 5
BND
3
= (2 + 23)
Time-Slot 0
mod BPF
Bit 0
384
206
Bit 4
= (2 – 17 + 256)
4
mod 256
Bit 7
1
= 25
Bit 3
5
Time-Slot 0
D
Bit 6
= 19
2
mod 256
Bit 2
H
6
Application Hints
= 241
Bit 5
3
PMOD
PCSR URE = 1
PCSR :
PEB 20550
PEF 20550
D
= F1
:
:
DRE
PSM
ITT08042
H
=
01.96
=
1
1