Philips Semiconductors

Product specification

SCN2652/SCN68652

Multi-protocol communications controller (MPCC)

1995 May 01

19

TRANSMIT – END OF BOP MESSAGE

TxC

MARK

TxSO

DBEN

LOAD LAST CHAR

SET TEOM

RESET TEOM

TxE2

TxA3

NOTES:

1.

dropped.

2.

TxE can be dropped before resetting TEOM if TxBE (corresponding to the closing FLAG) is high. Alternatively TxE can remain high and a new message initiated.

3.

TxA goes low after TxE has been dropped and 1 1/2 TxC’s after the last bit of the closing FLAG has been transmitted.

FLAG

CRC

LAST CHAR

NEXT TO LAST CHAR

TxBE1

SD00068

Figure 13. Timing Diagrams (cont.)

TRANSMIT TIMING – END OF BCP MESSAGE

TxC

MARK

TxSO

DBEN

LOAD LAST CHAR

SET TEOM

RESET TEOM

TxE

TxA

NOTE:

1.

When SCN2652 generated CRC is not required. TEOM should only be set if SYNCs are to follow the message block. In that case, TxE should be dropped in response to TxBE

(which corresponds to the start of transmission of the last character). When CRC is required, TxE must be dropped before CRC transmission is complete. Otherwise, the contents

of TxDB will be shifted out on TxSO. This facilitates transmission of contiguous messages.

CRC1

LAST CHAR

NEXT TO LAST CHAR

TxBE

SD00069

Figure 14. Timing Diagrams (cont.)