Bt8370/8375/8376
Fully Integrated T1/E1 Framer and Line Interface
3.16 Data Link Registers
3
3.16 Data Link Registers
Unused bits indicated by a dash (—) are reserved and should be written to 0. Writing to reserved bits has no
effect.
The Bt8370 and Bt8375 contain two independent Data Link Controllers (DL1, DL2) that are programmed to
send and receive HDLC formatted or unformatted serial data over any combination of bits within a selected time
slot. The serial data channels operate at a multiple of 4 kbps, up to the full 64 kbps time slot rate, by selecting a
combination of time slot bits from odd, even, or all frames. DL1 and DL2 each contain a 64-byte receive and
64-byte transmit buffer which function as programmable length circular buffers or as full-length data FIFOs.
The Bt8376 device contains only a single controller, DL1.
0A4—DL1 Time Slot Enable (DL1_TS)
7
6
5
4
3
2
1
0
DL1_TS[7]
DL1_TS[6]
DL1_TS[5]
DL1_TS[4]
DL1_TS[3]
DL1_TS[2]
DL1_TS[1]
DL1_TS[0]
DL1_TS[7]
DL1_TS[6, 5]
Unchannelized—Test mode only, all time slots selected. Zero for normal operation.
Frame Select—Transmit and receive data link 1 operates on data only during specified T1/E1
frames. Frame select options give the processor access to different types of data link channels
and overhead channels. Overhead bit insertion is performed after TDL1, so internal transmitter
overhead insertion must be bypassed [TFRM; addr 072] before processor-supplied overhead
can be output from TDL1.
00 = all frames
01 = even frames only
10 = odd frames only
11 = reserved
DL1_TS[4:0]
Time Slot Word Enable—Transmit and receive data link 1 operates on data only during the
specified time slot. During T1 mode, selecting time slot 0 enables data link operation on the
F-bit positions.
DL1_TS[4:0]
00000
00001
|
Time slot Enable
F-bit (T1) or TS0 (E1)
TS1
|
11110
11111
TS30
TS31
N8370DSE
Conexant
3-91