AN93
Rev. 1.4
75
+ITF = <high>,
<low>,
<report_period>
Transmit Flow Control Thresholds.
<high> Threshold
above which the modem will generate a flow
off signal. The parameter's unit is a byte. The valid range is 0-1023.
The
default is 895
.
<low>
Threshold below which the modem will generate a flow
on signal. The parameter's unit is a byte. The valid range is 0-1023.
The
default is 128
.
<report_period>The poll interval for the <EM><bnum><octnum0><oct-
num1> report. The valid range is 0–300 in 10 ms units.
The default
value of 0 indicates that reporting is disabled
.
Prior to a V.34 call, the modem dynamically splits the TX buffer to
accommodate the required DLE-shielding of in-band data. This resizing
affects the Transmit Flow Control Threshold settings. If the <on> or <off>
threshold setting is greater than 512, it is reduced by 512 to accommo-
date the buffer splitting. For example, the default <high> setting of 895
would be reduced to 383 (895 – 512 = 383) prior to a V.34 call. See
Figure 3, “Transmit Data Buffers,” on page 22 and Figure 4, “Receive
Data Buffers,” on page 22 for the sizing and operation of TX and RX
elastic buffers.
Notes:
1.
The <low> parameter must be set greater than the data frame size plus 2
(to accommodate the terminating <DLE><ETX> characters). Therefore,
the default <low> setting of 128 is appropriate for a frame size of 64
octets but not for a frame size of 256 octets. For this case, the <low>
setting must be greater than 258.
2.
The optimum <high> parameter setting depends on the driver latency;
specifically, how many bytes are transmitted to the modem after the
modem's CTS signal becomes deasserted. If little or no data are
transmitted after CTS becomes deasserted, the <high> parameter can
be set to a value close to the TX buffer size for maximum buffer utilization
(e.g. a setting of 500 for V.34 applications). If significant data are
transmitted after CTS becomes deasserted, the <high> parameter must
be chosen to preclude TX buffer overrun.
+MR=X
Modulation reporting control.
X Mode
0 Disabled
1 Enabled
If enabled, the intermediate result code is transmitted at the point during
connect negotiation. The format of this result code is as follows:
+MCR: <carrier> e.g. +MCR: V32B
+MRR: <rate> e.g. +MRR: 14400
Table 49. Basic AT Command Set (Continued)
Command
Action
Summary of Contents for Si2404
Page 2: ...AN93 2 Rev 1 4 ...
Page 200: ...AN93 200 Rev 1 4 Figure 31 TAM Handset and Speakerphone Voice Paths ...
Page 201: ...AN93 Rev 1 4 201 Figure 32 Si3000 Codec Gain and Signal Selection Options ...
Page 290: ...AN93 290 Rev 1 4 Figure 57 256 Band Spectral Display Figure 58 2048 Band Spectral Display ...
Page 305: ...AN93 Rev 1 4 305 Figure 76 Parallel or SPI Port Interrupt Service Flowchart ...