Method for specifying execution of only one of a pair of I/O command blocks in a chain structure
US5797034A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 15, 1996 |
| Grant date | Aug 18, 1998 |
| Priority date | — |
| Expiry date | Mar 15, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F13/126
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An I/O command block, that is stored in a memory, includes information for connecting the I/O command block to other I/O command blocks in a chain structure. The I/O command block chain structure allows simultaneity of execution, provides a mechanism to inhibit and enable execution of an individual I/O command block, and a mechanism for establishing precedence in the sequence of execution of the I/O command blocks. This level of capability is provided by only information in the I/O command blocks within the chain. In this method, an abort bit in each of the one and another I/O command blocks is set and an aborted bit is reset in each of the one and another I/O command blocks. Upon execution of the one and another I/O command blocks, in one embodiment, the execution of that I/O command block first initiating data transfer sets the aborted bit in the I/O command block pointed to by the offshoot block pointer in the I/O command block first initiating data transfer. After the aborted bit is set, the I/O command block is aborted at the next opportunity during execution of the I/O command block when the state of the aborted bit is checked.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.