DS33X81+ Maxim Integrated Products, DS33X81+ Datasheet - Page 90

• 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

The final two bytes of the TYPE/tHEC field are used to perform header validation. The tHEC calculation is a CRC-
16 operation in which the two byte PLI is multiplied by X
Another common representation for this polynomial is 0x1021. The initialization value for the operation is 0x0000.
The MSB of the PLI is bit 16, and the resulting remainder of the operation is the tHEC. To avoid requiring this
algorithm implementation in the user’s software, some common Type and the corresponding tHEC values are
provided in the table below.
Table 8-19. Example GFP Type + tHEC Values
When receiving either GFP Null or GFP Linear Extension frames from the WAN, the PP.DMCR.DR1E bit should be
set to 1 in order to remove the incoming GFP Type and tHEC bytes from the data stream.
The ITU-T G.8040 specification requires that when using GFP over a PDH link, the VCAT byte position must not be
used for payload information. The reservation or usage of the VCAT byte position is selected via the
VCAT.TCR3.TNVCGC bit.
Rev: 063008
________________________________________________ DS33X162/X161/X82/X81/X42/X41/X11/W41/W11
Configuration
Client Data, Includes pFCS, GFP Null, Ethernet
Client Data, No pFCS, GFP Null, Ethernet
Client Data, Includes pFCS, GFP Linear, Ethernet
Client Data, No pFCS, GFP Linear, Ethernet
Management Data, Includes pFCS, GFP Null, Ethernet
Management Data, No pFCS, GFP Null, Ethernet
Management Data, Includes pFCS, GFP Linear, Ethernet
Management Data, No pFCS, GFP Linear, Ethernet
16
and divided (modulo 2) by the polynomial X
GFP Type (hex)
1001
0001
1101
0101
9001
8001
9101
8101
tHEC (hex)
08CA
3BFB
0BB9
1352
1021
2063
2310
3888
16
+X
90 of 375
12
+X
5
+1.