S3033 AMCC (Applied Micro Circuits Corp), S3033 Datasheet - Page 20

• Manufacturer Part Number: S3033
• Description: Bicmos Lvpecl Clock Generator Sonet/sdh/atm Oc-12 Transmitter And Sonet/sdh/atm Oc-3/oc-12 Transceiver
• Manufacturer: AMCC (Applied Micro Circuits Corp)

Figure 11. OOF Operation Timing
20
RECEIVER FRAMING
Figure 10 shows a typical reframe sequence in
which a byte realignment is made. The frame and
byte boundary detection is enabled by the rising
edge of OOF and remains enabled while OOF is
High. Both boundaries are recognized upon receipt
of the third A2 byte which is the first data byte to be
reported with the correct byte alignment on the out-
going data bus (POUT[7:0]). Concurrently, the frame
pulse is set High for one POCLK cycle.
When interfacing with a section terminating device,
the OOF input remains High for one full frame after
the first frame pulse while the section terminating
device verifies internally that the frame and byte
alignment are correct, as shown in Figure 11. Since
at least one framing pattern has been detected since
the rising edge of OOF, boundary detection is dis-
abled when OOF is set Low.
Figure 10. Frame and Byte Boundary Detection
NOTE 1. Range of input to output delay can be 1.5 to 2.5 POCLK cycles
S3035
OOF
FP
RECOVERED
POUT[7:0]
REFCLK
CLOCK/
POCLK
RSD
OOF
FP
BOUNDARY DETECTION ENABLED
A1
A1
SONET/SDH/ATM OC-3/12 TRANSCEIVER W/CDR
A1
A1
Invalid Data
A1
Figure 12. Alternate OOF Timing
The frame and byte boundary detection block is acti-
vated by the rising edge of OOF, and stays active
until the first FP pulse or until OOF goes Low, which-
ever occurs last. Figure 11 shows a typical OOF
timing pattern which occurs when the S3035 is con-
nected to a down stream section terminating device.
OOF remains High for one full frame after the first
FP pulse. The frame and byte boundary detection
block is active until OOF goes Low.
Figure 12 shows the frame and byte boundary detec-
tion activation by a rising edge of OOF, and
deactivated by the first FP pulse.
OOF
A2
FP
A1
A2
A2
A2
BOUNDARY DETECTION ENABLED
A2
A2
April 12, 2000 / Revision D
A2 (28H)
Valid
Data
Note 1
A2