Bt8370/8375/8376
Fully Integrated T1/E1 Framer and Line Interface
3.17 System Bus Registers
TSIG_AB
TSIG_AB—AB Signaling. In T1 mode, only AB signaling bits are updated from TSIGI to the
TSIGn buffer. If SIGFRZ is active, the output CD signaling bits are copied from the buffered
output AB bits, respectively. In E1 mode, setting TSIG_AB forces C = 0 and D = 1 when
updating the TSIGn buffer.
0 = ABCD Signaling
1 = AB Signaling
ASSIGN
Assign System Bus Time Slot—During T1 line applications where the system bus group
consists of 32 time slots, or a multiple of 32, any 24 out of 32 time slots can be assigned. The
only time SBC [1:24] must be assigned is during 1536K or 1544K bus modes. The number of
assigned system bus time slots must equal the number of line time slots; therefore, ASSIGN
must be active in all 32 SBCn locations during E1 modes. The receiver does not update
unassigned time slots as it fills the RSLIP buffer. T1 time slots are filled sequentially from
RSLIP 1 to 24. Time slots 0 and 25 to 31 are reserved for unassigned values. Values are read
from either assigned or unassigned locations in a sequential fashion based on the ASSIGN bit.
System bus output data for unassigned time slots is taken from the RSLIP buffer, which the
processor can fill with any desired 16-bit fixed value (8 bits in RSLIP_LO, plus 8 bits in
RSLIP_HI).
0 = unassigned system bus time slot
1 = assigned system bus time slot
100–11F—Transmit Per-Channel Control (TPCn; n = 0 to 31)
7
6
5
4
3
2
1
0
TB7ZS/EMFBIT
TLOOP
TIDLE
TLOCAL
TSIGA/TSIGO
TSIGB/RSIGO
TSIGC
TSIGD
TB7ZS/EMFBIT
Bit 7 Zero Code Substitution/Embedded F-bit Value (Applicable in T1 mode only)—For
assigned system bus time slots [ASSIGN; addr 0E0-0FF], TB7ZS replaces bit 7 of the time
slot with a one if examination of 8-bit output detects all zeros. For an unassigned time slot
where TIDLE is active, EMFBIT replaces all embedded F-bit outputs with the programmed
EMFBIT value.
0 = no effect or force embedded F-bit (low)
1 = enable B7ZS or force embedded F-bit (high)
N8370DSE
Conexant
3-129
CONEXANT [ CONEXANT SYSTEMS, INC ]
