PEF2054NV21XT Lantiq, PEF2054NV21XT Datasheet - Page 119

• Manufacturer Part Number: PEF2054NV21XT
• Manufacturer: Lantiq

Specifications of PEF2054NV21XT

• Lead Free Status / Rohs Status: Compliant

marks bit 7 of the CFI time slot called TSN according to the following formula:
CTAR:TSN6 … 0 = TSN + 2
e.g. CTAR must be set to 02
= 0). See examples.
Note that the value of TSN may not exceed the actual number of time slots per CFI
frame:
TSN = [ – 2; I – 3], I = total number of time slots per CFI frame
From the zero offset bit position (CBSR = 20
upstream) can be shifted by up to 5 bits to the left (within the time slot
number TSN programmed in CTAR) and by up to 2 bits to the right (within the previous
time slot N – 1) by programming the CBSR:CDS2 … 0 bits:
Table 18
CBSR:CDS2 … 0
000
001
010
011
100
101
110
111
The bit shift programmed to CBSR:CDS2 … 0 affects both the upstream and
downstream frame position in the same way.
If CBSR:CUS3 … 0 = 0000, the upstream frame is aligned to the downstream frame.
With CBSR:CUS3 … 0 = 0001 to 1111, the upstream CFI frame can be shifted relative
to the downstream frame by up to 15 bits to the left as indicated in figure 41.
CFI Time Slot Adjustment and Bit Shift
If CBSR = 20
Semiconductor Group
H
, the CFI framing signal (PFS if CMD1:CSS = 0 or FSC if CMD1:CSS = 1)
Time Slot #
TSN – 1
TSN – 1
TSN
TSN
TSN
TSN
TSN
TSN
H
if the framing signal should mark time slot 0, bit 7 (TS
119
Marked Bit #
1
0
7
6
5
4
3
2
H
) the CFI frame (downstream and
Bit Shift
2 bits to the right
1 bit to the right
no bit shift
1 bit to the left
2 bits to the left
3 bits to the left
4 bits to the left
5 bits to the left
Application Hints
PEB 2055
PEF 2055