Rainbow Electronics DS2180A - Manual (Page 9)

DS2180A
041995 9/36
TRANSMIT SIGNALING
When enabled (via TCR.4) channel signaling is inserted
in frames 6 and 12 (193S) or in frames 6, 12, 18 and 24
(193E) in the 8th bit position of every channel word.
Signaling data is sampled at TABCD on the falling edge
of TCLK during bit 8 of each input word during signaling
frames. Logical combination of clocks TMO, TSIGFR
and TSIGSEL allows external multiplexing of separate
serial links for A, B or A, B, C, D signaling sources.
TTR1–TTR3: TRANSMIT TRANSPARENCY REGISTERS Figure 6
(MSB) (LSB)
CH8 CH7 CH6 CH5 CH4 CH3 CH2 CH1 TTR1
CH16 CH15 CH14 CH13 CH12 CH11 CH10 CH9 TTR2
CH24 CH23 CH22 CH21 CH20 CH19 CH18 CH17 TTR3
SYMBOL POSITION NAME AND DESCRIPTION
CH24 TTR3.7 Transmit Transparent Registers. Each of these bit positions represents a
CH1 TTR1.0 DS0 channel in the outgoing frame. When set, the corresponding channel
is transparent.
TIR1–TIR3: TRANSMIT IDLE REGISTERS Figure 7
(MSB) (LSB)
CH8 CH7 CH6 CH5 CH4 CH3 CH2 CH1 TIR1
CH16 CH15 CH14 CH13 CH12 CH11 CH10 CH9 TIR2
CH24 CH23 CH22 CH21 CH20 CH19 CH18 CH17 TIR3
SYMBOL POSITION NAME AND DESCRIPTION
CH24 TIR3.7 Transmit Idle Registers. Each of these bit positions represents a DS0
CH1 TIR1.0 channel in the outgoing frame. When set, the corresponding channel will
output an idle code format determined by TCR.2.
TRANSMIT CHANNEL TRANSPARENCY
Individual DS0 channels in the T1 frame may be pro-
grammed clear (no inserted robbed bit signaling and no
bit 7 zero suppression) by setting the appropriate bits in
the transmit transparency registers. Channel transpar-
ency is required in mixed voice/data or data-only envi-
ronments such as ISDN, where data integrity must be
maintained.
TRANSMIT IDLE CODE INSERTION
Individual outgoing channels in the frame can be pro-
grammed with idle code by asserting the appropriate
bits in the transmit idle registers. One of two idle code
formats, 7F (Hex) and FF (Hex) may be selected by the
user via TCR.3. If enabled, robbed bit signaling data is
inserted into the idle channel, unless the appropriate
TTR bit is set for that channel. This feature eliminates
external hardware currently required to intercept and
stuff unoccupied channels in the DS1 bit stream.