ort82g5 Lattice Semiconductor Corp., ort82g5 Datasheet - Page 73

• Manufacturer Part Number: ort82g5
• Description: Xaui And Fc Fpscs
• Manufacturer: Lattice Semiconductor Corp.

Table 30. ORT82G5 Memory Map (Continued)
Lattice Semiconductor
30A02
Common Status Registers xx=[AA,...,BD]
30A03
Recommended Board-level Clocking for the ORT42G5 and ORT82G5
Option 1: Asynchronous Reference Clocks Between Rx and Tx Devices
Each board that uses the ORT42G5 or ORT82G5 as a transmit or receive device will have its own local reference
clock as shown in Figure 37. Figure 37 shows the ORT82G5 device on the switch card receiving data on two of its
channels from a separate source. Data tx1 is transmitted from a tx device with refclk1 as the reference clock and
Data tx2 is transmitted from a tx device with refclk2 as the reference clock. Receive channel AA locks to the incom-
ing data tx1 and receive channel AB locks to the incoming data tx2.
The advantage of this clocking scheme is the fact that it is not necessary to distribute a reference clock (typically
156 MHz for 10GE and 155.52 MHz for OC-192 applications) across a backplane.
Figure 37. Asynchronous Clocking Between Rx and Tx Devices
Option 2: Synchronous Reference Clocks to Rx and Tx Devices
In this type of clocking, a single reference clock is distributed to all receive and transmit devices in a system
(Figure 38). This distributed clocking scheme will permit maximum flexibility in the usage of transmit and receive
channels in the current silicon such as:
• All transmit and receive channels can be used within any quad in receive channel alignment or alignment bypass
• In channel alignment mode, each receive channel operates on its own independent clock domain.
Absolute
Address
mode.
(0x)
[0:1]
[3:7]
[2:7]
Bit
[2]
[0]
[1]
REFCLK 1
REFCLK 2
RX_FIFO_MIN
FMPU_RESYNC8
SYNC8_OVFL
SYNC8_OOS
Reserved for future use.
Name
PORT CARD #1
PORT CARD #2
—
ORT42G5
ORT82G5
ORT42G5
ORT82G5
or
or
Reset
Value
(0x)
00
00
MSb’s for the threshold for low address in RX_FIFOs. RX_FIFO_MIN, Bit
1 is MSb. Useful values for RX_FIFO_MIN [0:4] are 0 to 17(decimal).
Resynchronizes all 8 channels when it transitions from 0 to 1. Status is a
0 on device reset.
Reserved for future use.
Read-Only Multi-Channel Overflow Status. When SYNC8_OVFL=1,
8-channel synchronization FIFO overflow has occurred.
SYNC8_OVFL=0 on device reset.
Read-Only Multi-Channel Out-Of-Sync Status. When SYNC8_OOS=1,
8-channel synchronization has failed. SYNC8_OOS=0 on device reset.
T
T
X
X
1
2
73
BACKPLANE
ORCA ORT42G5 and ORT82G5 Data Sheet
AC
AD
ORT42G5
ORT82G5
SWITCH
CARD
Description
or
REFCLK 3