Dismiss
InnovationQ will be updated on Sunday, Oct. 22, from 10am ET - noon. You may experience brief service interruptions during that time.
Browse Prior Art Database

Combined "Command-Status" Structure for Configuration Bits

IP.com Disclosure Number: IPCOM000019524D
Publication Date: 2003-Sep-17
Document File: 2 page(s) / 328K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method that uses a single configuration bit which acts as both a command and status register. Benefits include allowing for a function to start or stop in a predictable manner, so that software-hardware coherency is maintained even after the function has been stopped.

This text was extracted from a Microsoft Word document.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 73% of the total text.

Combined “Command-Status” Structure for Configuration Bits

Disclosed is a method that uses a single configuration bit which acts as both a command and status register. Benefits include allowing for a function to start or stop in a predictable manner, so that software-hardware coherency is maintained even after the function has been stopped.

Background

Typically there are two types of configuration register bits: command-type and status-type.

The command-type configuration bits are latch-based structures (see Figure 1). These bits are typically written (i.e. set and cleared) only by software, and the hardware performs actions based on the value of the configuration bit. The status-type configuration bits are typically set by hardware and cleared by software. These bits are usually implemented as flops with set and clear muxes at the D input of the flop.

General Description

In the disclosed method, when command bits are cleared by software, they reflect the status of the hardware until the hardware disables the function; therefore, these bits behave as both command and status bits. The properties of the configuration bits are as follows:

  • If the software sets the bit, the controller sees it immediately but the software does not. The controller takes action on the bit and then generates one clock enable signal to allow the software read bit to be set.
  • If the software clears the bit, the controller sees it immediately but the software does not. The controller takes action on...