DS33X81+ Maxim Integrated Products, DS33X81+ Datasheet - Page 56

• Manufacturer Part Number: DS33X81+
• Description: IC MAPPING ETHERNET 256CSBGA
• Manufacturer: Maxim Integrated Products

Specifications of DS33X81+

• Applications: Data Transport
• Interface: Parallel/Serial
• Voltage - Supply: 1.8V, 2.5V, 3.3V
• Package / Case: 256-CSBGA
• Mounting Type: Surface Mount
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

8.12.3 Link Capacity Adjustment Scheme (LCAS)
The Link Capacity Adjustment Scheme (LCAS) provides the capability to add and remove members from a VCAT
VCG. If LCAS is enabled viaVCAT.RCR2.LE[3:0], the receive LCAS block will extract all LCAS frame information
from the VCAT overhead. The LCAS status registers report the CTRL, GID, RS-ACK, and MST fields of the VCAT
frame. The LCAS CTRL field communicates the intent to add or remove a member from the group. The device
coordinates the addition or removal of links from the group of active members so that changes are hitless.
The transmit MST values are automatically controlled by the device by default. Optionally, this function can be
controlled by user software via the VCAT.TLCR3–VCAT.TLCR6 registers. The Transmit MST field communicates
the condition of the line (e.g., an LOM alarm), the reception of an Add command (and subsequent successful
alignment to the VCG), and the reception of a Remove command.
To enable Transmit LCAS, follow the initialization steps outlined in Section 8.12.2.2. Note that the
VCAT.TLCR8.CTRL[3:0] bits should be initialized with a CTRL command of IDLE. All changes to the CTRL[3:0]
register bits must be followed with a zero-to-one transition on VCAT.TCR1.TLOAD for the change to take effect.
Receive LCAS
• Aligns all members of the VCG
• Reports relevant fields and alarms to status registers
• Automatically transmits MST back to the Source (Manual control also configurable)
Transmit LCAS
• Outputs CTRL, MST, GID, RS-Ack to be inserted into VCAT overhead
• GID PRBS generator and insertion
• User-Configured GID insertion
• CRC generation and insertion
8.12.3.1Example LCAS Operation
Rev: 063008
________________________________________________ DS33X162/X161/X82/X81/X42/X41/X11/W41/W11
1. Initial CTRL command of IDLE, SQ value = max (16 for T1/E1, 8 for T3/E3)
2. Addition of Member:
3. Removal of Member
4. Response to Receive LCAS reporting MST=FAIL
a. Send ADD command, Change SQ value to 1+ SQ value(active link with the highest SQ)
b. Wait for MST=OK on Receive LCAS (VCAT.RLSR1 register)
c. Send EOS on this port; Port that was sending EOS now sends NORM
a. Change command from NORM/EOS to IDLE; Change SQ value to max; Reorder other active
a. If the Receive LCAS reports that a MST value changed from OK to FAIL, the Transmit LCAS
b. The SQ value remains the same.
c. If the member that changes to DNU was EOS, EOS must be assigned to the member next in line.
members’ SQ; If change was from EOS to IDLE, then next highest member changes from NORM
to EOS
should send DNU on that port.
Functions:
Functions:
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