Rainbow Electronics DS2130Q - Manual (Page 8)

DS2130Q
041295 8/22
TONE CONTROL REGISTER
The Tone Control register provides access to the tone
generator and controls power-down and reset func-
tions.
The tone generator is controlled by bits TS0-3, which
cause either transmission of a DTMF digit or one of
three possible single-tone sine waves. The DTMF digits
that can be transmitted are 0-9, # and *. The single
tones available are 350, 620 and 1004 Hz, any of which
can be used as beeps for user prompting. Tone genera-
tion lasts for as long as the particular state is pro-
grammed; all tone generation ceases when TS0-3
equal 1111 (the power-up state). When writing a new
value for TS0-3 (including the 1111 state), the TRST bit
must be simultaneously set to a 1; otherwise, the old val-
ue of TS0-3 will continue to be used. It is recommended
that DTMF digits be sustained for at least 50 mS for
proper network recognition.
The CPD2 bit is used in conjunction with CPD1 (in the
VCR) to enable a power-down mode in which power
consumption is reduced to a minimum. CPD1 and
CPD2 must both equal a 1 to enter this mode. The
PCMOUT output is three-stated when CPD2 = 1.
Testing of the DTMF generation and detection circuitry
can be accomplished by setting TLB to a 1. In this mode,
transmit DTMF tones are internally looped back to the
DTMF receiver for test purposes (the DT0-3 pins can be
monitored for proper operation). Also in this mode, input
PCM data is looped back to the appropriate time slot on
PCMOUT. This permits isolation and testing of the ex-
ternal codec/filter used with the DS2130.
TONE CONTROL REGISTER Figure 5
(MSB) (LSB)
TS3 TS2 CPD2 TRST TLB TS1 TS0 -
SYMBOL POSITION NAME AND DESCRIPTION
TS3
TS2 TCR.7
TCR 6 Tone selects 0-3. See Table 3 for tone bit mapping.
TRST m st be
ritten to a 1 hen a ne tone al e is to TS2
TS1 TCR.6
TCR.2
pp g
TRST must be written to a 1 when a new tone value is to
be written.
TS1
TS0 TCR.2
TCR.1 be written.
CPD2 TCR.5 Compression/Expansion power-down 2.
0 = Normal operation
0 = Normal operation
1 = Power-down all DSP operation. CPD1 must equal 1
as well CPD1=0 while CPD2=1 should not be pro-
as well. CPD1=0 while CPD2=1 should not be pro-
grammed.
TRST TCR.4 Tone generation reload enable for TS0-3.
0 = normal operation/ready for new value
0 = normal operation/ready for new value
1 = load new tone value
TLB TCR.3 Tone generation loopback.
0 = normal operation
0 = normal operation
1 = loopback tone signals to DTMF receiver
- TCR.0 Should always be set to 1.