DS2181A

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TSD INPUT TIMING Figure 7

CAS OUTPUT FORMAT IN TIMESLOT 16 Figure 8

FRAME 0

1

FRAME 1

FRAME 15

0000XYXX

ABCD for

Timeslot 1

ABCD for

timeslot 17

ABCD for

Timeslot 15

ABCD for

Timeslot 31

NOTE:

1. Timeslot 16 of frame 0 is reserved for the multiframe alignment word (0000), distant multiframe

alarm (Y) and extra bits (X-XX).

TINR: TRANSMIT INTERNATIONAL AND NATIONAL REGISTER Figure 9

(MSB)

(LSB)

INB

-

TRA

NB4

NB5

NB6

NB7

NB8

SYMBOL

POSITION

NAME AND DESCRIPTION

INB

TINR.7

International Bit. Inserted into the outgoing data stream when

TCR.4 = 1.

-

TINR.6

Reserved; must be 0 for proper operation.

TRA

TINR.5

Transmit Remote Alarm

0 = Normal operation; bit 3 of timeslot 0 in non-alignment frame

clear.

1 = Alarm condition; bit 3 of timeslot 0 in non-align frames set.

NB4

TINR.4

Transmit National Bits. Inserted into the outgoing data stream at

TPOS and TNEG when TCR.3 = 1.

NB5

TINR.3

NB6

TINR.2

NB7

TINR.1

NB8

TINR.0

TRANSMIT INTERNATIONAL AND NATIONAL DATA

Bit 1 of timeslot 0 in all frames is known as the international bit. When TCR.4 = 1, the transmitted

international bit is sourced from TINR.7. When TCR.4 = 0, the transmitted international bit is sampled at

TIND during the first bit period of each frame. The international bit positions in all outgoing frames

except 13 and 15 are replaced by CRC4 code words and the CRC4 multiframe alignment signal when

CCR.3 = 1.