ort8850 Lattice Semiconductor Corp., ort8850 Datasheet - Page 44

• Manufacturer Part Number: ort8850
• Description: Field-programmable System Chip Fpsc Eight-channel X 850 Mbits/s Backplane Transceiver
• Manufacturer: Lattice Semiconductor Corp.

Lattice Semiconductor
SPE and C1J1 Identification
In the ORT8850 each frame can be considered as 12 STS-1s. In the SPE region, there are 12 J1 pulses for each
STS-1s. There is one C1(J0, new SONET specifications use J0 instead of C1 as section trace to identify each STS-
1 in an STS-N) pulse in the TOH area for one frame. Thus, for non concatenated data there are a total of 12 J1
pulses and one C1(J0) pulse per frame. The C1(J0) pulse is coincident with the J0 of STS-1 #1.
The pointer interpreter identifies the payload area of each frame. The SPE flag is active when the data stream is in
SPE area. SPE behavior is dependent on pointer movement and concatenation. Note that in the TOH area, H3 can
also carry valid data. When valid SPE data is carried in this H3 slot, SPE is high in this particular TOH time slot. In
the SPE region, if there is no valid data during any SPE column, the SPE signal will be set to low. SPE allows a
pointer processor to extract payload without interpreting the pointers.
Figure 23. SPE and C1J1 Functionality for STS -12
The following rules are observed for generating SPE and C1J1 signals:
• On occurrence of AIS-P on any of the STS-1, there is no corresponding J1 pulse.
• In case of concatenated payloads (up to STS48c), only the head STS-1 of the group has an associated J1 pulse.
• The C1J1 signal tracks any pointer movements.
This behavior is illustrated in the following figure. Note that the actual bit positions are dependent on the actual pay-
load configuration and offset.
Figure 24. SPE and C1J1 Signals
Pointer Mover
After the pointer interpreter comes the pointer mover block. There is a separate pointer mover for the two SONET
framer quads, A and B, each of which handles up to one STS-48 (four channels) The K1/K2 bytes and H1-SS bits
are also passed through to the pointer generator so that the FPGA can receive them. The pointer mover handles
both concatenations inside the STS-12, and to other STS-12s inside the core. Use of this block is optional, as dis-
cussed in a later section.
STS-12
STS-12
SPE
C1J1
SPE
0
0
1
1
A1 A1 A1 A1 A1 A1 A1 A1 A1 A1 A1 A1 A2 A2 A2 A2 A2 A2 A2 A2 A2 A2 A2 A2 J0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0
C1J1
0
1
0
1
TOH information excluding C1(J0) of STS-1 #1.
Position of C1(J0) of STS-1 #1 (one per frame). Typically used to provide a unique link identification
(256 possible unique links) to help ensure cards are connected into the backplane correctly or cables
are connected correctly.
SPE information excluding the 12 J1 bytes.
Position of the 12 J1 bytes.
TOH ROW # 1
44
Description
C1 PULSE
ORCA ORT8850 Data Sheet
1 2 3 4 5 6 7 8 9 10 11 12
first SPE BYTES OF THE
12 STS-1S
SPE ROW # 1
J1 PULSE OF
3RD STS-1