Method for controlling a bus to progress transfer cycles without inserting a cycle for acknowledgement
US5774679A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 30, 1996 |
| Grant date | Jun 30, 1998 |
| Priority date | — |
| Expiry date | Dec 30, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F13/364
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An information processing system wherein a module to operate as a master which executes a read access to a module to operate as a slave requests a bus arbiter to afford the mastership of a bus with a bus mastership request signal, and it simultaneously asserts a last cycle signal so as to notify the bus arbiter of the fact that the next cycle will be the last cycle to be used by the master. Subsequently, when the master has had the use of the bus granted by a bus use grant signal from the bus arbiter, it transfers an address to the slave by the use of the bus in the next cycle, thereby starting the read access. After the read access, the master releases the bus mastership. Only when the slave has failed to accept the transferred address, does it assert a retry request signal two cycles after the transfer cycle of the address not accepted. In this case, the module having executed the transfer two cycles before the cycle of the asserted signal executes again the transfer executed before. Thus, the address to be transferred can be transferred to the module ready to accept the address, in only one cycle.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.