公开(公告)号：CA1319997C

公开(公告)日：1993-07-06

申请号：CA609856

申请日：1989-08-30

Applicant: IBM

Inventor： DAVIS GORDON T ,  LANDA ROBERT E ,  MANDALIA BAIJU D ,  VAN DEN BERG JAN W ,  VAN VOORHIS DAVID C

IPC: G06F13/00 ,  G06F13/12 ,  H04L29/06 ,  H04L29/10 ,  H04L29/08

Abstract: BC-9-88-008 SPECIALIZED COMMUNICATIONS PROCESSOR FOR LAYERED PROTOCOLS A special purpose communications protocol processor (CPP) provides more efficient processing of layered communication protocols -- e.g. SNA (Systems Network Architecture) and OSI (Open Systems Interconnection) --than contemporary general purpose processors, permitting hitherto unavailable operations relative to high speed communication links. The CPP contains special-purpose circuits dedicated to quick performance (e.g. single machine cycle execution) of functions needed to process header and frame information, such functions and information being of the sort repeatedly encountered in all protocol layers, and uses instructions architected to operate these circuits. The header processing functions given special treatment in this manner include priority branch determination functions, register bit reshaping (rearranging) functions, and instruction address processing functions. Frame processing functions so handled include CRC (cyclic redundancy check) computations, bit insertion/deletion operations and special character detection operations.

公开(公告)号：CA1118864A

公开(公告)日：1982-02-23

申请号：CA315395

申请日：1978-10-31

Applicant: IBM

Inventor： NAGEL DENNIS M ,  O'NEAL DOUGLAS M ,  PETROSKEY PAUL W ,  VAN DEN BERG JAN W ,  WILDES DONALD V ,  WU DAVID C-K

IPC: H04L69/14 ,  G06F13/00 ,  G06F13/22 ,  G06F13/40 ,  H04J3/16

Abstract: PROGRAMMABLE COMMUNICATIONS SUBSYSTEM A micro processor controlled user programmable communications multiplexer subsystem (herein referred to by the symbol PCS) capable of transmitting and receiving data on any one or more of 32 communications lines simultaneously. Each line may be dynamically assigned to a variety of communication characteristics, such as line speeds, character lengths, synchronous, or asynchronous operation, and code structures as well as protocol selections. The system of the invention provides the capability for the user to write his communications programs using novel operations commands that provide code structure and protocol independence as well as communication line independence. Various hardware features and queuing techniques are employed in order to maintain high transmission rates. Variable line scanning in the Teleprocessing Time Division Multiplexer of the PCS is programmably permissible; i.e., the time base for line scanning is fixed and is a multiple of the communication line rate, although the actual line to be scanned is programmably variable. The program ability is provided by a continuously scanned storage array which contains physical line addresses of the time division multiplexer. The scanning mechanism, while running, prioritizes the transmit buffer servicing of the individual lines. BC9-77-00 DLM/TT25