Browse Prior Art Database

Improved Subsystem Control Block Architecture for Personal Computers

IP.com Disclosure Number: IPCOM000113301D
Original Publication Date: 1994-Aug-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 2 page(s) / 67K

Publishing Venue

IBM

Related People

Louie, TJ: AUTHOR [+2]

Abstract

Described is an improved architecture for Personal Computers (PCs) which utilize Subsystem Control Block (SCB) delivery pipes to enable low-cost non-microprocessor based busmasters to utilize the SCB delivery pipes with a minimum of support logic.

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This is the abbreviated version, containing approximately 52% of the total text.

Improved Subsystem Control Block Architecture for Personal Computers

      Described is an improved architecture for Personal Computers
(PCs) which utilize Subsystem Control Block (SCB) delivery pipes to
enable low-cost non-microprocessor based busmasters to utilize the
SCB delivery pipes with a minimum of support logic.

      Typically, the support of the SCB architecture pipe delivery
mechanism requires a large amount of resource for the generation of
pipe displacements in the determination of 32-bit physical addresses
and to manipulate pipe pointers.  The complexity of delivery
mechanism operations of ten implies the need for imbedded
intelligence, such as a microprocessor.  The SCB architecture defines
a number of Event Control Elements (ECEs) as a subset of the control
elements used in the SCB delivery service.  The ECEs are used to
synchronize the operations associated with the in-bound delivery
pipes.  A wrap event informs the destination delivery agent that the
associated delivery queue has wrapped and that the next ECE should be
dequeued from the top of the delivery queue.  Generation of the wrap
element adds additional complexity to the delivery agent logic when
implemented in non-microprocessor based physical structures.

      The concept described herein provides a simplified physical
delivery mechanism that requires minimal address, space, and function
code capabilities from the physical delivery structure.  The concept
provides a specification that allows the designer to support the SCB
pipe delivery mechanism with a much smaller amount of design
resource.  Imbedded microprocessor intelligence is no longer
required.  The support m...