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Browse Prior Art Database

Bus Timing/Skew Measurement Tool

IP.com Disclosure Number: IPCOM000111919D
Original Publication Date: 1994-Apr-01
Included in the Prior Art Database: 2005-Mar-26
Document File: 2 page(s) / 49K

Publishing Venue

IBM

Related People

Takayama, M: AUTHOR [+3]

Abstract

Disclosed is a tool which enables the dynamic bus timing/skew margin verification without any modification of the system and applications. This tool verifies whether the BUS Slave(ex. Adapter card) and BUS Master (e.g., Processor) satisfy the BUS timing specification and have enough timing margins between them.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 75% of the total text.

Bus Timing/Skew Measurement Tool

      Disclosed is a tool which enables the dynamic bus timing/skew
margin verification without any modification of the system and
applications.  This tool verifies whether the BUS Slave(ex.  Adapter
card) and BUS Master (e.g., Processor) satisfy the BUS timing
specification and have enough timing margins between them.

      This tools holds the BUS cycles for a short duration, and
regenerates each signal at a previously programmed time.  This tool
is logically inserted on the BUS between the Processor(Master) and
the Adapter(Slave).  To verify a dynamic timing/skew margin, the tool
works as Slave to the BUS Master (Fig. 1, A-BUS) and as Master to the
BUS Slave (Fig. 1, B-BUS).  At each Memory/IO  READ/WRITE cycle, the
tool holds A-BUS for a short duration and regenerates the new BUS
signal timing to B-BUS as previously programmed.  The Programmable
Delay circuit regenerates the BUS signal timing not only "within the
BUS timing specification", but also "out of range".

Timing/skew resolution depends on the Programmable Delay circuit
(Fig. 1).

        Resolution    :       0.5 nano Sec/Step (fine)
                                10.0 nano Sec/Step (coarse)
             Dynamic Range :     256   steps
             ( for PCMCIA, ISA, Micro Channel* case )

Duration of A-BUS HOLD time is shown as below;

         T(HOLD A)= T(HOLD B)+T(tool propagat...