Apparatus and method for fast I/O data transfer in an intelligent cell
US5206935A · kind A · utility
Inventors
Key dates
| Filing date | Mar 26, 1991 |
| Grant date | Apr 27, 1993 |
| Priority date | — |
| Expiry date | Mar 26, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F13/32
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A specialized apparatus and method for providing fast programmed I/O for transferring information in a multi-processor environment which includes a CPU, and a memory coupled to an I/O port across an internal data bus. Multiple bytes of data are transferred in successive processing cycles to the I/O port from the memory, or from the I/O to the memory by first determining the upper limit for the number of bytes that are going to be transferred. This number and the memory start address are then stored in CPU registers. The I/O module is then checked by the CPU to see if a data byte is available from an external device. If a data byte is available, the I/O module is instructed to place the data byte on the bus for storage within the memory at the start address. The address is then incremented and the count is decremented. The above procedure is repeated until the count drops to zero, after which time the next instruction is fetched.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.