RFX144V24-S23 and RFX96V24-S23 Modem Designer’s Guide
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Table 3-1. Interface Memory Bit Definitions (Cont'd)
Mnemonic
Location
Default
Name/Description
TTONEE
0E:7
0
Tone Transmit Enable. In speakerphone mode, control bit TTONEE enables (TTONEE = 1) or disables
(TTONEE = 0) tone transmit mode. Depending upon the status of TONEIE and TONEXE, the
corresponding voice channel will be muted for the whole period of the tone transmit mode. TTONEE
must be reset in order to re-activate voice channel.
TRIG
0A:6-7
0
Interrupt Triggering. These two bits select how the programmable interrupt is to occur if this interrupt is
enabled (PIE bit = 1). The host has the option to be continuously interrupted whenever the interrupt
condition is true (DC level triggered), to be interrupted only when the interrupt condition transitions from
false to true (positive edge triggered), to be interrupted only when the interrupt condition transitions from
true to false (negative edge triggered), or to be interrupted when the interrupt condition transitions from
false to true or from true to false (edge triggered):
Bit 7
Bit 6
Description
0
0
DC Level Triggered
0
1
Positive Edge Triggered
1
0
Negative Edge Triggered
1
1
Edge Triggered
TXSQ
14:7
0
Transmitter Squelch. When control bit TXSQ is set, the transmitter analog output is squelched (forced
to zero). All other transmitter functions continue as normal. When TXSQ is reset, the transmitter output
functions normally. (V.23)
UE
08:3
0
Underrun Error (Parallel Mode). If the host does not load in a new byte of data within X bit times of the
modem setting bit TDBE, an underrun condition occurs and UE is set by the modem, The actual number
of bit times depends upon the number of stop bits and word size selected. (V.23)
The modem will reset UE whenever it sets TDBE.
V23HDX
15:0
0
V.23 Half Duplex. When control bit V23HDX is set, the modem operates in V.23/1200 half duplex. The
transmitter and receiver must be set to the same V.23 configuration, 1200 bps (CONF = 24h). Carrier is
under RTS control. The RTS-CTS delay is adjustable in DSP RAM. ANS should also be set to zero.
VOLDWN
0E:5
0
Volume Down. In speakerphone, Voice Codec and Audio Codec modes, the volume control to the XIA
DAC is decreased by 2 dB each time the VOLDWN bit is set. The VOLDWN bit is automatically reset by
the modem.
VOLUP
0E:6
0
Volume Up. In speakerphone, Voice Codec and Audio Codec modes, the volume control to the XIA
DAC is increased by 2 dB each time control bit VOLUP is set. The VOLUP bit is automatically reset by
the modem.
VOVUN
17:0
0
Voice Overrun or Underrun. In voice/audio codec mode, status bit VOVUN is set when the host fails
to access the DBUFF input or output before new data is needed or available. VOVUN is reset when the
voice/audio coder/decoder data buffer is available for proper data transfer. An overrun condition in the
voice/audio coder suspends recording of new samples until the host reads DBUFF.
An underrun condition in the voice/audio decoder suspends playback of data until the host writes
DBUFF input.
VOX
17:3
0
Voice Detected. In voice/audio codec mode, status bit VOX is set when the voice/audio coder is
detecting voice/audio and is reset when the voice/audio coder is not detecting voice/audio.
VOXREC
1A:3
0
Voice Activated Recording. In voice/audio codec mode, when control bit VOXREC is a 1 and CDEN is
a 1, message encoding is delayed until status bit VOX is set (thus eliminating encoding of beginning
message silence). Voice activated recording provides maximum RAM storage efficiency. When
VOXREC is a 0, message encoding is not delayed.
Summary of Contents for RFX144V24-S23
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