Bt8370/8375/8376
3.16 Data Link Registers
Fully Integrated T1/E1 Framer and Line Interface
0AC—TDL #1 End Of Message Control (TDL1_EOM)
7
6
5
4
3
2
1
0
—
—
—
—
—
—
—
—
TDL1_EOM
End of Transmit Message—Writing any data value to TDL1_EOM marks the last byte of data
written into the transmit FIFO as the end of an HDLC message (FCS or non-FCS mode), or the
end of a transmit circular buffer. The processor must write TDL1_EOM after writing a
complete message or after writing the last byte of a circular buffer into TDL1 [addr 0AD]. The
written data value is ignored and cannot be read back. Multiple HDLC messages are allowed
to be queued in the transmit FIFO simultaneously. The transition from one circular buffer to
another occurs only after the end of message byte of the current circular buffer has been sent.
0AD—Transmit Data Link FIFO #1 (TDL1)
7
6
5
4
3
2
1
0
TDL1[7]
TDL1[6]
TDL1[5]
TDL1[4]
TDL1[3]
TDL1[2]
TDL1[1]
TDL1[0]
TDL1[7:0]
Transmit Message Data—Output by the transmitter data link, from LSB to MSB, and sent on
the selected time slot bits. The processor writes 8-bit FIFO data during HDLC and Pack8
modes. During Pack6 mode, only the six least significant bits TDL1[5:0] are used.
0AE—TDL #1 Status (TDL1_STAT)
7
6
5
4
3
2
1
0
—
—
—
—
TMSG1
TMPTY1
TNEAR1
TFULL1
TMSG1
In-Progress Transmit Message—The real-time status of the transmit message sequencer is
provided mostly for diagnostic purposes. During HDLC modes, TMSG1 is high for the
interval between opening and closing FLAG characters to indicate the transmitter is actively
pulling data bytes from transmit FIFO locations. TMSG1 is low while the channel transmits
FLAG or Abort characters. During Unformatted and Circular Buffer modes, TMSG1 is high
continuously.
0 = channel idle
1 = channel actively emptying FIFO
TMPTY1
Transmit FIFO Empty—Indicates no message data is present in transmit data link FIFO. This
is typically checked by the processor in response to a TMSG or TNEAR interrupt. If a TMSG
interrupt occurs, the processor checks TMPTY1 to determine whether all queued messages
were sent (TMPTY1=1) or more queued messages remain to be sent (TMPTY1=0). If TNEAR
interrupt occurs, the processor confirms TMPTY1=0 to verify that the partial transmit message
was not aborted by a FIFO underrun.
0 = FIFO contains data to be transmitted
1 = FIFO empty
3-100
Conexant
N8370DSE
CONEXANT [ CONEXANT SYSTEMS, INC ]
