Browse Prior Art Database

Data Transfer for PIO To/From System Using Streaming Data

IP.com Disclosure Number: IPCOM000099254D
Original Publication Date: 1990-Jan-01
Included in the Prior Art Database: 2005-Mar-14
Document File: 1 page(s) / 44K

Publishing Venue

IBM

Related People

Arimilli, R: AUTHOR [+3]

Abstract

Programmed I/O (PIO) to/from System Memory is an which was defined to resolve a cache coherency between the processor and a First Party Direct Access(DMA) Master on the MICRO CHANNEL* I/O Bus. the I/O Channel Controller(IOCC) and the processor cached memory which presents an exposure that they have different images of the current memory contents. PIO to/from System Memory(PSM) operation routes the memory access through the IOCC cache to insure a view of System Memory for the First Party DMA Adapter the processor.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 91% of the total text.

Data Transfer for PIO To/From System Using Streaming Data

       Programmed I/O (PIO) to/from System Memory is an which was
defined to resolve a cache coherency between the processor and a
First Party Direct Access(DMA) Master on the MICRO CHANNEL* I/O Bus.
the I/O Channel Controller(IOCC) and the processor cached memory
which presents an exposure that they have different images of the
current memory contents. PIO to/from System Memory(PSM) operation
routes the memory access through the IOCC cache to insure a view of
System Memory for the First Party DMA Adapter the processor.

      The PSM operation was implemented in the IOCC by the PIO
operation, executing an IOCC-controlled transfer, then completing the
PIO Load or Store.  To the it is seen as a special First Party DMA
operation is initiated by the processsor.  The IOCC implements
operation by transferring data from a PIO Buffer to a Buffer (PIO
Writes) or from a DMA Buffer to a PIO Buffer Reads). This
buffer-to-buffer transfer is performed to a data alignment function
inherent in the PSM  This data transfer is a controlling factor in
the performance of the PSM operation.

      MICRO CHANNEL I/O Bus data transfers can follow either basic
data transfer protocol or the Streaming Data mode which provides
twice the performance of the basic  The IOCC implemented the PSM
operation under the Data protocol for optimum performance.  The IOCC
was able to share considerable logic with the CHANNEL I/O Bus
Stream...