Data transmission system including the downloading of a first program for the interruption of a second program

• US 4,882,705 A
• Filed: 08/02/1988
• Issued: 11/21/1989
• Est. Priority Date: 12/07/1984
• Status: Expired due to Term

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Yasue, Kazuo
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): Ruiz, Adolfo
• Application Number:
  US07/227,461
• Time in Patent Office: 476 Days
• Field of Search: 364/200 MS File, 364/900 MS File
• US Class Current: 714/53
• CPC Class Codes: H04L 12/00 Data switching networks interconnection of, or transfer of information or other signals between, memories, input/output devices or central processing units G06F13/00

Abstract

In a data transmission system in which a plurality of stations each including a processor are interconnected by links, each processor is constituted by a memory device, which when receives a command containing a program from other station, stores a program contained in the command from a predetermined address, a register which, when receives the command representing a condition of starting the program, stores the information, an addressing circuit supplying an address signal to the memory device, a comparator comparing with each other the outputs of the addressing circuit and the register and a subroutine call means for executing the program when the output of the comparator shows a coincidence.

Claims

1. A data transmission system comprising:

a transmission link;

at least one first station connected to said transmission link; and

a plurality of second stations connected to said transmission link;

said first station including means for transferring to a selected one or more of said second stations a first program and a first address representing a condition to start execution of the first program in said second station;

each of said second stations including first storage means for storing a second program prior to the transferring of the first program and first address,

second storage means for storing the first address transmitted from said first station,

third storage means for storing the first program transferred from said first station in a storage area starting from a third address,

address register means for sequentially storing second addresses for addressing said first storage means and said third storage means,

means for executing the programs stored in said first storage means and said third storage means in accordance with the second addresses sequentially stored in said address register means,

coincidence detecting means for detecting a coincidence between the first address stored in said second storage means and the second address stored in said address register means during execution of said second program, and

means for interrupting, after the first program and the first address are transferred from said first station to said second station, the execution of the second program to start execution of the first program stored in said third storage means by storing the third address into said address register means when said detecting means detects the coincidence during execution of said second program, the second program continuing to be executed if the coincidence is not detected during the execution thereof.