txc-03456 TranSwitch Corporation, txc-03456 Datasheet - Page 43

• Manufacturer Part Number: txc-03456
• Description: Device Level Mapper
• Manufacturer: TranSwitch Corporation

Receive J1 Byte Processing
There are two possible received J1 message sizes, 16 bytes (ITU-T), or 64 bytes (ANSI). The L4M is capable
of dimensioning the transmit (and receive) RAM memory segment to the two sizes (16-Byte or 64-Byte). In
addition, two modes of operation are provided for the 16-byte (ITU-T) format: a microprocessor read mode,
and a compare read mode. The following table lists the various control states associated with J1 processing.
CCITT
0
1
1
J1COM
X
0
1
Transmit and receive J1 segments are configured for the 64-byte J1 message
size. No relationship is required between the memory segment and the mes-
sage written for transmission or for the message received.
Transmit and receive J1 segments are configured for the 16-byte J1 message
size. No relationship is required between the memory segment and the mes-
sage written for transmission or the message received.
Transmit and receive J1 segments are configured for the 16-byte J1 message
size. No relationship is required between the memory segment and the mes-
sage written for transmission. For the receive J1 bytes, a 16-byte microproces-
sor message is written into a 16-byte segment for comparison against the
received message. The written message must start with the multiframe indicator
written into the starting location of the segment. The L4M does not perform the
CRC check in the 16-byte message.
DATA SHEET
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Action
Ed. 1A, January 2000
TXC-03456
TXC-03456-MB
L4M