US 5,632,020 AGranted

System for docking a portable computer to a host computer without suspending processor operation by a docking agent driving the bus inactive during docking

AssigneeAdvanced Micro Devices, Inc.

InventorsDouglas D. Gephardt, Scott Swanstrom

Life of this patent

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Abstract

A computer system includes a bus arbiter for providing immediate access to a bus in response to an external requirement or event. In a dockable computer system capable of hot docking or warm docking, the bus arbiter grants exclusive, non-preemptive access to the buses to the docking agent which is capable of quieting (rendering inactive) the bus of the portable computer and docking station in response to a notice signal. The notice signal is indicative of a change of states from the undocked state to the docked state or from the docked state to the undocked state. The notice signal may be provided from software, a user-actuated switch, or an infrared signal. In an audio-capable computer, the bus arbiter provides exclusive non-preemptive access to the digital signal processing peripheral device so that audio glitches are avoided. The arbiter preferably includes an override circuit for countermanding the fairness scheme employed by the bus arbiter and granting immediate bus access in response to the external event or condition. The bus arbiter preferably is able to provide fixed or rotating priority for bus accesses of other peripheral devices on the bus. The arbiter is preferably integrated with the main processor of the computer system.

Claims24

Dependent claims

A portable computer for use in a dockable computer system capable of assuming at least two states, a docked state and undocked state, said dockable computer system including a notice circuit for providing a notice signal when said dockable computer system is about to change states, and a host station including a host bus communicating with a host connector, said portable computer comprising:

a central processing unit;
a computer connector;
a connector bus coupled to said computer connector;
a computer bus communicating to said computer connector via said connector bus, said central processing unit coupled to said computer bus, said host connector physically coupled with said computer connector when said dockable computer system is in said docked state, said host connector being physically separate from said computer connector when said dockable computer system is in said undocked state;
an in-line docking agent communicating with said computer bus, said docking agent including a QUIET REQUEST output to provide a QUIET REQUEST signal, said docking agent being coupled between said host bus and said computer bus when said system is in the docked state, said docking agent being coupled between said connector bus and said computer bus, said docking agent being capable of providing buffering or driving capabilities for said computer bus;
and
a bus arbiter receiving said QUIET REQUEST signal, said bus arbiter granting ownership of said computer bus to said docking agent in response to said QUIET REQUEST signal, wherein said docking agent quiets said computer bus and said connector bus by ensuring that there are no active transfers occurring on said computer bus and said connector bus when said bus arbiter grants ownership of said computer bus to said docking agent, wherein said portable computer remains powered on and said central processing unit remains operational while said portable computer changes between said two states.

4 more elements

A method of docking a portable computer having a computer bus and a host station having a host bus, said portable computer including a processor, a notice circuit for generating a notice signal in response to an impending docking or undocking of said portable computer, an in-line docking agent coupled between said computer bus and a connector bus, said in-line docking agent communicating with said computer bus and generating a PRIMARY REQUEST signal in response to said notice signal, and peripheral devices communicating with said computer bus, a bus arbiter for granting access to said computer bus, said computer bus being physically, electrically coupled with said host bus when said portable computer is docked with said host station, said docking agent being coupled between said host bus and said computer bus when said portable computer is docked with said host station, said method comprising the steps of:

granting time bound access to said computer bus to said docking agent in response to said PRIMARY REQUEST signal, said docking agent quieting said computer bus and said connector bus by ensuring that there are no active transfers occurring on said computer bus and said connector bus, in response to being granted access by said bus arbiter;
coupling said host bus and said computer bus;
buffering data signals between host data lines on said host bus and portable computer data lines on said computer bus with said docking agent;
and
allowing said peripherals to have access to said computer bus after said host bus and computer bus are coupled, whereby said portable computer remains powered on without suspending operation of said processor when said portable computer is docked with said host station.

2 more elements

In a dockable computer system comprised of a host computer station, including a station bus, and a mobile computer unit including a unit bus, wherein said system is capable of residing in at least two distinct states, a docked state in which said mobile computer unit is operatively associated with said host computer station and an undocked state in which said mobile computer unit is physically separate from said host computer station, an improvement comprising of:

an in-line mobile docking agent coupled between a first connector bus and said unit bus, said in-line mobile docking agent providing a QUIET REQUEST signal in response to said system changing between said states;
a bus arbiter receiving said QUIET REQUEST signal, said bus arbiter granting control of said unit bus to said docking agent in response to said QUIET REQUEST signal, wherein said docking agent quiets said unit bus and said first connector bus by ensuring that there are no active transfers occurring on said computer bus and said first connector bus in response to being granted control of said unit bus;
and
a station docking control circuit coupled between a second connector bus and said station bus, said station docking control circuit quieting said station bus and said second connector bus by ensuring that there are no active transfers occurring on said computer bus and said second connector bus in response to said system changing between said states.

1 more element

Dependencies are inferred from the claim text.

Facts

Application: 08/255,663Filed 9 Jun 1994 · continuation in part
Priority: 25 Mar 1994
Granted: 20 May 1997
Term ends: Not estimatedThe source records don’t support an estimate.

Classification5 codes

G06F 13/4081
Electrical coupling: live connection to bus, e.g. hot-plugging
G06F 1/1632
For portable computers: external expansion units, e.g. docking stations
G06F 13/364
With centralised access control: using independent requests or grants, e.g. using separated request and grant lines
G06F 13/4031
Using bus bridges: with arbitration