Browse Prior Art Database

Program Selection of BSC or SDLC

IP.com Disclosure Number: IPCOM000085911D
Original Publication Date: 1976-Jun-01
Included in the Prior Art Database: 2005-Mar-03
Document File: 2 page(s) / 40K

Publishing Venue

IBM

Related People

Carter, DW: AUTHOR [+2]

Abstract

Binary Synchronous Communication (BSC) or Synchronous Data Link Communication (SDLC) protocols are program selectable by the computer system operator. In the computer system of Fig. 1, the operator selects the appropriate communication protocol, BSC or SDLC program in main storage 10. The central processing unit (CPU) 20 is directed by the selected program to load the BSC or SDLC microcode into the communications I/O control region of control storage 15. This microcode upon being executed issues a command to set the BSC or SDLC mode of communication, Fig. 2.

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Program Selection of BSC or SDLC

Binary Synchronous Communication (BSC) or Synchronous Data Link Communication (SDLC) protocols are program selectable by the computer system operator. In the computer system of Fig. 1, the operator selects the appropriate communication protocol, BSC or SDLC program in main storage 10. The central processing unit (CPU) 20 is directed by the selected program to load the BSC or SDLC microcode into the communications I/O control region of control storage 15. This microcode upon being executed issues a command to set the BSC or SDLC mode of communication, Fig. 2.

Received data on line 21, Fig. 3, is applied to a serializer - de serializer (SERDES) 22. The received data is buffered in buffer 23 and is also applied to flag detect block 24 and to SYN detect block 25. The outputs of blocks 24 and 25 are applied to AND circuits 26 and 27, respectively. AND circuits 26 and 27 are, respectively conditioned by SDLC MODE and BSC MODE signals from mode latch 28. Mode latch 28 is set in the BSC or SDLC mode by the command resulting from execution of the micro-code.

The outputs of AND circuits 26 and 27 are applied to OR circuit 29 which feeds sync detection 30. Sync detection 30 places the communications adapter in synchronization with the incoming data stream, by controlling the transfer of data from buffer 23 to data channel 35.

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