Filter
Top Products
119
FOUR CONSECUTIVE FRAMES CONTAINING FRAMING PATTERN ERRORS
A1 A1 A1 A2 A2 A2 A1 A1 A1 A2 A2 A2 A1 A1 A1 A2 A2 A2 A1 A1 A1 A2 A2
A1/A2 ERRORA1/A2 ERRORA1/A2 ERRORA1/A2 ERROR
A2 C1 C1 C1
RX_DATA[7:0]
RX_SONETCLK
OOF
The out of frame declaration timing diagram (Figure 40) illustrates the declaration of out of frame. In an
STS-3 (STM-1) stream, the framing pattern is a 48-bit sequence that repeats once per frame. Out of frame
is declared when one or more errors are detected in this pattern for four consecutive frames as illustrated.
In the presence of random data, out of frame will normally be declared within 500 µs.
Figure 40. Out of Frame Declaration
3 ms
3 ms
RX_SONETCLK
OOF
LOF
Figure 41. Loss of Frame Declaration/Removal
The loss of frame declaration/removal timing diagram (Figure 41) illustrates the operation of the LOF
output. LOF is an integrated version of OOF. LOF is declared when an out of frame condition persists for
3 ms. LOF is removed when an in frame condition persists for 3 ms.
RX_DATA[7:0]
RX_SONETCLK
LAISRDI
625 µs (5 FRAMES)
K1
K2
C1
C1
C1
625 µs (5 FRAMES)
K1
K2
C1 C1 C1
Figure 42. Line AIS and Line RDI Declaration/Removal
The line AIS and line RDI declaration/removal timing diagram (Figure 42) illustrates the operation of the
LAIS and RDI outputs. A byte serial STS-3 (STM-1) stream is shown for illustrative purposes. LAIS (RDI)
is declared when the binary pattern 111 (110) is observed in bits 6,7, and 8 of the K2 byte for three or five
consecutive frames. LAIS (RDI) is removed when any pattern other than the binary pattern 111 (110) is
observed in bits 6,7, and 8 of the K2 byte for three or five consecutive frames.