Intel confidential – Intel 537EX User Manual

Page 61

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536EX Chipset Developer’s Manual

61

Intel Confidential

Error Correction and Data Compression

+DS44=m

3, 0, 0,

471,
942,
140,
140,

1884,

3768

V.44 Data Compression: This command controls the V.44 data compression function if provided in the
DCE. It accepts the following sub parameters:

m=[<direction>[,<compression_negotiation>[,<capability>[,<max_codewords_tx>[,<max_codewords_rx>
[,<max_string_tx>[,<max_string_rx>[,<max_history_tx>[,<max_history_rx>]]]]]]]]]

<direction> specifies the desired direction(s) of operation of the data compression function.

0

Negotiated… no compression

1

Transmit only

2

Receive only

3

Both directions, accept any direction

<compression_negotiation> specifies whether or not the DCE should continue to operate if the desired
result is not obtained.

0

Do not disconnect if Rec. V.44 is not negotiated by the remote DCE as specified in
<direction>. Always set to 0.

<capability> specifies the use of stream method, packet method, multi-packet method.

0

Stream method

1

Packet method

2

Multi-packet method

<max_codewords_tx> specifies the maximum number of codewords which should be negotiated in the
transmit direction.

256 to 65536

<max_codewords_rx> specifies the maximum number of codewords which should be negotiated in the
receive direction.

256 to 65536

<max_string_tx> specifies the maximum string length to be negotiated in the transmit direction.

32 to 255

<max_string_rx> specifies the maximum string length to be negotiated in the receive direction.

32 to 255

<max_history_tx> specifies the maximum size of the history buffer to be negotiated in the transmit
direction.

512

<max_history_rx> specifies the maximum size of the history buffer to be negotiated in the receive
direction.

512

+EFCS=m

0

32-bit Frame Check Sequence: Controls the use of 32-bit frame check sequence option in V.42.

0

Use 16-bit FCS

1

Use 32-bit FCS if available in remote DCE; otherwise use 16-bit FCS

2

Use 32-bit FCS if available in remote DCE; otherwise disconnect

Table 21. V.44/V.42/V.42 bis and MNP Data Modem Command Descriptions (Continued)

Command

Default

Description

NOTE: An asterisk (*) denotes the factory-default setting.

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