Bidirectional dual port serially controlled programmable read-only memory
US4402067A · kind A · utility
Inventors
Key dates
| Filing date | Feb 21, 1978 |
| Grant date | Aug 30, 1983 |
| Priority date | — |
| Expiry date | Feb 21, 1998 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C17/12
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A bidirectional serially controlled programmable read-only memory has a serial input/output (I/O) port and a parallel I/O port. By selecting the appropriate control inputs, the instant invention can receive serial address or data information and output data to either the parallel or serial I/O ports. In a like manner, an address at the parallel I/O port can be utilized to generate output data in either a serial or parallel form. In general, the parallel I/O port will be utilized to transfer data to and from a microprocessor, whereas the serial I/O port will be utilized to transfer data to and from an external interface. By proper utilization of the control circuits and appropriate use of the control signals, data may be read from the bidirectional PROM in parallel form from the parallel I/O port or in serial form from the serial I/O port. In addition, data may be transferred from the serial I/O port to the parallel I/O port or from the parallel I/O port to the serial I/O port. Multiplexing means and register means interact with the control circuits to formulate the data transfers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.