DS21354/DS21554 3.3V/5V E1 Single-Chip Transceivers
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9.2.2.
Transmit Side
Via the THSE control bit (CCR3.2), the DS21354/DS21554 can be set up to take the signaling data
presented at the TSIG pin and insert the signaling data into the PCM data stream that is being input at the
TSER pin. The hardware signaling insertion capabilities of each framer are available whether the
transmit-side elastic store is enabled or disabled. If the transmit-side elastic store is enabled, the
backplane clock (TSYSCLK) must be 2.048MHz/4.096MHz/8.192MHz.
When hardware signaling insertion is enabled on a framer (THSE = 1), then the user must enable the
Transmit Channel Blocking Register Function Select (TCBFS) control bit (CCR3.6 = 1). This is needed
so that the CAS multiframe alignment word, multiframe remote alarm, and spare bits can be added to
time slot 16 in frame 0 of the multiframe. The TS1 register should be programmed with the proper
information. If CCR3.6 = 1, then a zero in the TCBRs implies that signaling data is to be sourced from
TSER (or TSIG if CCR3.2 = 1) and a one implies that signaling data for that channel is to be sourced
from the Transmit Signaling (TS) registers. See definition below.
TCBR1/TCBR2/TCBR3/TCBR4: DEFINITION WHEN CCR3.6 = 1
(MSB)
(LSB)
CH18 CH3 CH17 CH2 CH16 CH1 1*
1* TCBR1(22)
CH22 CH7 CH21 CH6 CH20 CH5 CH19 CH4
TCBR2(23)
CH26 CH11 CH25 CH10 CH24 CH9 CH23 CH8
TCBR3(24)
CH30 CH15 CH29 CH14 CH28 CH13 CH27 CH12
TCBR4(25)
*
These bits should be set to one to allow the internal TS1 register to create the CAS Multiframe Alignment Word and Spare/Remote Alarm bits.
The user can also take advantage of this functionality to intermix signaling data from the TSIG pin and
from the internal Transmit Signaling Registers (TS1 to TS16). As an example, assume that the user
wishes to source all the signaling data except for voice channels 5 and 10 from the TSIG pin. In this
application, the following bits and registers would be programmed as follows:
CONTROL BITS
REGISTER VALUES
THSE = 1 (CCR3.2)
TS1 = 0Bh (MF alignment word, remote alarm etc.)
TCBFS = 1 (CCR3.6)
TCBR1 = 03h (source time slot 16, frame 1 data)
T16S = 0 (TCR1.5)
TCBR2 = 01h (source voice Channel 5 signaling data from TS6)
CBR3 = 04h (source voice Channel 10 signaling data from TS11)
TCBR4 = 00h