Intel 537EX manual Intel Confidential, Error Correction and Data Compression

Error Correction and Data Compression

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

Command	Default		Description
		Set break control: Defines what action the modem takes when a break (attention signal) is sent or
		received, as described below:
		where n =,
		In connect state, transmits break to remote (if in reliable mode):
		0, 2, 4	Enters command mode, no break sent
		1	Destructive/expedited
		3	Nondestructive/expedited
\Kn	5	5	Nondestructive/nonexpedited
		In command state, transmits break to remote (if in reliable mode):
		0, 1	Destructive/expedited
		2, 3	Nondestructive/expedited
		4, 5	Nondestructive/nonexpedited
		In connect state, receives break at modem port and sends to serial port:
		0, 1	Destructive/expedited
		2, 3	Nondestructive/expedited
		4, 5	Nondestructive/nonexpedited
		Set Inactivity Timer: During a buffer (normal) or reliable connection, if no data is sent or received within
\Tn	0	the inactivity time period, the link is disconnected. The default, ‘0’, disables this feature.
		Range: 0–90 Length in minutes
		n = 0*	Disables inactivity timer
		Set XON/XOFF Pass-Through:If software flow control is enabled (\Q1), this command defines whether
		the XON (11h) and XOFF (13h) characters received from the DTE are sent to the remote modem. In
		addition, if the modem port flow control is enabled (\G1) in normal mode, the command specifies whether
		the XON and XOFF characters received from the remote modem are sent to the DTE. In both cases, flow
\Xn	0	control operation is not affected.
		Range: 0, 1
		n = 0*	Processes flow control characters*
		n = 1	Processes flow control characters and passes them through to the local or remote so they
			can process the characters.
		Set V.42 Detect Phase: In V.42 modes (+ES=3,0,2 and +ES=3,2,4), this command specifies whether the
		modem detects V.42, MNP, or no error-correcting protocols from the remote modem and changes to the
-Jn	1	appropriate mode. Otherwise, only V.42 is attempted.
		Range: 0, 1
		n = 0	Disables the V.42 detect phase
		n = 1*	Enables the V.42 detect phase
		V.42 bis Compression Control: This command specifies whether the data in the LAPM frames are
		compressed using V.42 bis data compression. This can improve throughput by as much as 400%.
		Compression can be negotiated to operate in one direction or both.
“Hn	3	Range: 0–3
		n = 0	Disables V.42 bis
		n = 1	Enables V.42 bis only when transmitting data
		n = 2	Enables V.42 bis only when receiving data
		n = 3*	Enables V.42 bis for both transmitting and receiving data
		V.42 bis String Length: This command specifies the maximum number of characters that can be
“On	32	compressed into one V.42 bis code word. The default value of 32 optimizes throughput for most file types.
		Range: 6–250 Number of characters
		n = 32*	Usual number of characters

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

536EX Chipset Developer’s Manual 59

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