Personal computer system with bus noise rejection

• US 5,313,593 A
• Filed: 09/17/1992
• Issued: 05/17/1994
• Est. Priority Date: 09/17/1992
• Status: Expired due to Fees

• Current Assignee: Lenovo Singapore Pte Limited (Lenovo Group Ltd.)
• Original Assignee: International Business Machines Corporation
• Inventors: Chin, Arthur L., Barakat, Edmond H., Schorn, Eric B.
• Primary Examiner(s): Fleming, Michael R.
• Assistant Examiner(s): AUVE, GLENN ALLEN
• Application Number:
  US07/947,018
• Time in Patent Office: 607 Days
• Field of Search: 395/325, 395/200, 395/275, 395/550, 371/4, 371/29.5, 371/61
• US Class Current: 710/315
• CPC Class Codes: G06F 13/4208 being a system bus, e.g. VME bus, Futurebus, Multibus

Abstract

This invention relates to personal computers, and more particularly to a personal computer system having a signal passing component operatively connected for exchange of data signals with system components operatively connected with a local processor bus and having a segment providing a state machine for receiving external command signals passed on one of the system busses and for passing internal command signals identifying valid data intervals, said state machine requiring a predetermined minimum length of external command signal for issuance of an internal command signal and terminating an internal command signal with termination of an external command signal so as to avoid the adverse effects of crosstalk and transmission line noise on external commands signals and loss of data integrity thereby possibly occurring.

Claims

1. A personal computer system comprising:

a local processor bus for passing data signals;

a microprocessor operatively connected with said local processor bus for transfer of data signals through said local processor bus;

an option bus for receiving option cards and for passing data signals to and from any option card received;

a planar I/O bus for passing data signals;

a bus controller operatively connected with said local processor bus and said option bus and said planar I/O bus for controlling passage of data signals between any two of said local processor bus and said option bus and said planar I/O bus to and from said microprocessor; and

a signal passing component operatively connected for exchange of data signals with system components operatively connected with said local processor bus and having a segment providing a state machine for receiving external command signals passed on one of said busses and for passing internal command signals identifying valid data intervals, said state machine requiring a predetermined minimum length of external command signal for issuance of an internal command signal and terminating an internal command signal with termination of an external command signal so as to avoid any adverse effects of crosstalk and transmission line noise on external command signals and loss of data integrity thereby possibly occurring.

2. A personal computer system in accordance with claim 1 wherein said state machine sequences the continuance of any internal command signal being passed to identify a valid data interval so as to terminate said continuance of said internal command signal being passed prior to the end of any valid data interval so identified.

3. A personal computer system comprising:

a local processor bus for passing data signals;

a microprocessor operatively connected with said local processor bus for transfer of data signals through said local processor bus;

an option bus for receiving option cards and for passing data signals to and from any option card received;

a planar I/O bus for passing data signals;

a bus controller operatively connected with said local processor bus and said option bus and said planar I/O bus for controlling passage of data signals between any two of said local processor bus and said option bus and said planar I/O bus to and from said microprocessor; and

an I/O controller having a plurality of segments,

a first one of said segments providing a serial port for exchange of data signals with said local processor bus,

a second one of said segments providing a parallel port for exchange of data signals with said local processor bus, and

a state machine for receiving external command signals passed on one of said busses and for passing internal command signals identifying valid data intervals, said state machine requiring a predetermined minimum length of external command signal for issuance of an internal command signal and terminating an internal command signal with termination of an external command signal so as to avoid any adverse effects of crosstalk and transmission line noise on external command signals and loss of data integrity thereby possibly occurring.

4. A personal computer system in accordance with claim 3 wherein said I/O controller is connected directly to said option bus.

5. A personal computer system in accordance with claim 3 wherein said I/O controller is connected directly to said planar I/O bus.

6. A personal computer system in accordance with claim 3 wherein said state machine sequences the continuance of any internal command signal being passed to identify a valid data interval so as to terminate said continuance of said internal command signal being passed prior to the end of any valid data interval so identified.