Bt8370/8375/8376
Fully Integrated T1/E1 Framer and Line Interface
3.15 Bit-Oriented Protocol Registers
3
3.15 Bit-Oriented Protocol Registers
Unused bits indicated by a dash (—) are reserved and should be written to 0. Writing to reserved bits has no
effect.
The Bit Oriented Protocol (BOP) transceiver sends and receives BOP messages, including ESF Yellow
Alarm, which consists of repeated 16-bit patterns with an embedded 6-bit codeword. The BOP message channel
is configured to operate over the same channel selected by the DL1 Time Slot Enable register [DL1_TS;
addr 0A4]. Therefore, DL1 must be configured and enabled to allow BOP operation, as described in Table 3-22.
Table 3-22. (Datalink Configuration Register Description)
Datalink Configuration
Value
Description
Enabling odd frames, Fbit(T1)
Registers
DL1_TS [addr 0A4]
DL1_BIT [addr 0A5]
DL1_CTL [addr 0A6]
RDL1_FFC [addr 0A7]
TDL1_FEC [addr 0AB]
0x40
0x00
0x03
Select bits to use in time slot.
Select normal FIFO mode, FCS, Tx enabled, Rx enabled.
###### is the threshold for receiver FIFO near full.
###### is the threshold for transmit FIFO near empty.
00######
00######
The BOP message channel must be configured to operate over the FDL channel for BOP messages to convey
Priority, Command, and Response codeword messages according to ANSI T1.403, Section 9.4.1. The
precedence of transmitted BOP messages with respect to current DL1 transmit activity is configurable
[TBOP_MODE; addr 0A0]. BOP messages can also be transmitted during E1 mode, although the 16-bit
codeword pattern has not been adopted as an E1 standard. BOP message format:
0xxxxxx011111111 (transmitted right to left)
[543210]6-bit codeword
0A0—Bit Oriented Protocol Transceiver (BOP)
7
6
5
4
3
2
1
0
RBOP_START
RBOP_INTEG
RBOP_LEN[1]
RBOP_LEN[0]
TBOP_LEN[1]
TBOP_LEN[0] TBOP_MODE[1] TBOP_MODE[0]
RBOP_START
BOP Receiver Enable—When active, the BOP receiver searches the FDL channel for data that
matches a 16-bit pattern in the form of 0xxxxxx011111111, where xxxxxx equals a 6-bit
codeword. Otherwise, the BOP receiver is disabled.
0 = disabled
1 = BOP receiver enable
N8370DSE
Conexant
3-87
CONEXANT [ CONEXANT SYSTEMS, INC ]
