
PRELIMINARY
XRT86SH328
211
REV. P1.0.6
28-CHANNEL DS1/E1 FRAMER/LIU WITH DS3 MUX & VT-MAPPER - SONET APPLICATIONS
BIT 7 - Transmit LAPD Any:
This READ/WRITE bit-field is used to configure the Transmit LAPD Controller block to transmit any kind of LAPD
Message (or HDLC Message) with a size of 82 bytes or less. If the user implements this option, then the Transmit LAPD
Controller block will be capable of transmitting any kind of HDLC frame (with any value of header bytes). The only
restriction is that the size of the HDLC frame must not exceed 82 bytes.
`
0 - Does not invoke this Any Kind of HDLC Message feature. In this case, the Transmit LAPD Controller block will
only transmit HDLC Messages that contains the Bellcore GR-499-CORE values for SAPI and TEI.
`
1 - Invokes this Any Kind of HDLC Message feature. In this case, the Transmit LAPD Controller block will be able to
transmit HDLC Messages that contains any header byte values.
N
OTE
:
If the Any Kind of HDLC Message feature is invoked, then the size of the information payload (in terms of bytes)
within the Transmit LAPD byte Count Register Address = 0x0E83) must be indicated.
BIT [6:4] - Unused:
BIT 3 - Auto Retransmit
This READ/WRITE bit-field is used to configure the Transmit LAPD Controller block to transmit PMDL messages,
repeatedly at one-second intervals. Once the user enables this feature, and then commands the Transmit LAPD
Controller block to transmit a given PMDL Message, then the Transmit LAPD Controller block will then proceed to
transmit this PMDL Message (based upon the contents within the Transmit LAPD Message Buffer) repeatedly at one
second intervals.
`
0 - Disables the Auto-Retransmit Feature:
In this case, the Transmit LAPD Controller block will only transmit a given PMDL Message once. Afterwards the
Transmit LAPD Controller block will proceed to transmit a continuous stream of Flag Sequence octets (0x7E) via the
DL bits, within each output DS3 frame. No more PMDL Messages will be transmitted until the user commands another
transmission.
`
1 - Enables the Auto-Retransmit Features
In this case, the Transmit LAPD Controller block will transmit PMDL messages (based upon the contents within the
Transmit LAPD Message buffer) repeatedly at one-second interval.s
N
OTE
:
This bit-field is ignored if the Transmit LAPD Controller block is disabled.
BIT 2 - Reserved:
BIT 1 - Transmit LAPD Message Length:
This READ/WRITE bit-field is used to specify the length of the payload data within the outbound LAPD/PMDL Message,
as indicated below.
`
0 - Configures the Transmit LAPD Controller block to transmit a LAPD/PMDL Message that has a payload data size
of 76 bytes.
`
1 - Configures the Transmit LAPD Controller block to transmit a LAPD/PMDL Message that has a payload data size
of 82 bytes.
BIT 0 - Transmit LAPD Controller Enable:
This READ/WRITE bit-field is used to enable the Transmit LAPD Controller block within the chip. Once the user enables
the Transmit LAPD Controller block, it will immediately begin transmitting the Flag Sequence octet (0x7E) to the remote
terminal via the DL within the outbound DS3 data-stream. The Transmit LAPD Controller block will continue to do this
until the user commands the Transmit LAPD Controller block to transmit a PMDL Message.
`
0 - Disables the Transmit LAPD Controller block.
T
ABLE
282: DS3 F
RAMER
B
LOCK
- T
RANSMIT
DS3 LAPD C
ONFIGURATION
R
EGISTER
(A
DDRESS
= 0
X
0E33)
B
IT
7
B
IT
6
B
IT
5
B
IT
4
B
IT
3
B
IT
2
B
IT
1
B
IT
0
Transmit
LAPD Any
Unused
Auto
Retransmit
Reserved
Transmit
LAPD Mes-
sage Length
Transmit
LAPD Con-
troller Enable
R/W
R/O
R/O
R/O
R/W
R/O
R/W
R/W
0
0
0
0
1
0
0
0