Browse Prior Art Database

User-Configurable Status Register

IP.com Disclosure Number: IPCOM000122166D
Original Publication Date: 1991-Nov-01
Included in the Prior Art Database: 2005-Apr-04
Document File: 2 page(s) / 80K

Publishing Venue

IBM

Related People

Millas, RJ: AUTHOR

Abstract

This article describes a technique for use in a microprocessor-based system which utilizes several status registers by the introduction of user-configurable status registers (UCSRs).

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

User-Configurable Status Register

      This article describes a technique for use in a
microprocessor-based system which utilizes several status registers
by the introduction of user-configurable status registers (UCSRs).

      Most microprocessor systems rely on status information to
determine what process to perform.  Microprocessor-based data
communications attachments require error and line status information
continuously.  Most of these systems contain several status
registers.

      The application code running on such systems must sometimes
read several status registers just to obtain the status information
required by the given application.  The number of status registers
that must be read depends on how the status bits are formatted within
the several status registers.  Having to read several status
registers to obtain information that could have been contained within
a single register adds to the software overhead.  These multiple
status register reads impact the performance of the system,
especially in high- speed applications, such as real time digital
signal processing.

      The UCSRs disclosed herein allow the application to configure
the format of the status registers to fit the specific requirements
of the code.

      Each UCSR consists of a configuration register bank (CRB), a
data selector bank (DSB), and a register, as shown in the block
diagram in Fig. 1.

      The initialization code of the application initializes the
contents of the configuration registers.  These values are used by
the DSB to select which status lines to include in the status
register.  In a typical system, several UCSRs can be implemented so
that the application can have status registers that re...