Electrical computers and digital processing systems: multicomput – Computer-to-computer protocol implementing – Computer-to-computer handshaking
Reexamination Certificate
1997-01-22
2001-01-30
Breene, John (Department: 2777)
Electrical computers and digital processing systems: multicomput
Computer-to-computer protocol implementing
Computer-to-computer handshaking
C710S120000, C710S020000
Reexamination Certificate
active
06182145
ABSTRACT:
TECHNICAL FIELD
The present invention relates to communication between electronic devices, and more particularly, to methods and apparatus for communication between two electronic devices, each according to its corresponding protocol.
BACKGROUND OF THE INVENTION
It is common for one electronic device (say, a personal computer—PC) to communicate information to an external electronic device (say, a printer) over an interconnection. Typically this interconnection is a wire cable configured for the specific purpose. One popular standard for communication between a PC and a printer is the Centronics standard. According to this standard, the information is transmitted in parallel form, so that all of the bits that make up each computer word of information are transmitted simultaneously to the external device over separate lines in the wire cable.
There are many protocols for communication between two electronic devices according to the scenario described above. Generally there is a “handshake” phase in which each of the two electronic devices confirms the presence of, and correct interconnection with, the other device. Next the device that is the source of the information prepares the first word of information to be transmitted. After the word is prepared and loaded into a data latch, the information source sends a signal to the information recipient to notify the recipient. The information recipient configures itself for receipt of the information and sends an acknowledgement signal back to the signal source. Thereafter, the first word of information is transmitted. Upon correct receipt of the word of information, the recipient sends a signal to the information source, verifying that the word was received. This process is then repeated until all of the intended information has been transmitted.
As technology has progressed, a number of different protocols have developed and so has the need for higher speed transfer of information between two electronic devices. As a result, certain standards for such protocols have been developed. As one example, they are described in “Standard Signaling Method for a Bidirectional Parallel Peripheral Interface for Personal Computers,” IEEE P1284 D1.00, published in draft form on Mar. 15, 1993. This document is hereby incorporated by reference. In accordance with such standards, it is important to be able to interconnect two electronic devices regardless of their own individual protocols. Further, once the two electronic devices are interconnected, it is important that the transfer of information be as fast as possible.
Heretofore, increased information transmission speeds have been realized by using wires in the interconnecting cable for purposes other than those for which they were originally intended. For example, wires that were originally intended for the bidirectional transfer of notification and acknowledgement signals are also used to transfer additional bits of the information, thereby increasing the cable's transmission speed capability. However, this approach typically requires changes in the software (and, possibly, the hardware) of the information source and recipient devices. If the source and recipient devices are then later used in other configurations, it may be necessary to change the software or hardware again for this new use. Accordingly, it is desirable to have an apparatus and method for providing a communications capability between two electronic devices without requiring that the two devices be reprogrammed.
SUMMARY OF THE INVENTION
According to one aspect, the invention is an apparatus for transferring information from a first electronic device to a second electronic device, wherein the first electronic device communicates through a first I/O port according to a first protocol and the second electronic device communicates through a second I/O port according to a second protocol. The apparatus comprises a circuit connected between the first and second I/O ports. The circuit is adapted to receive signals from the first and second electronic devices through the first and second I/O ports, respectively. The circuit is also configurable in response to the signals so that the circuit receives the information according to the first protocol through the first I/O port and transmit the information to the second electronic device through the second I/O port according to the second protocol.
In a further aspect, the invention is a method for transferring data information from a first electronic device to a second electronic device. In this method, the first electronic device communicates through a first I/O port according to a first protocol and the second electronic device communicates through a second I/O port according to a second protocol. The first and second I/O ports are connected by a transmission means structured to transmit data information according to a default base protocol mode. The default base protocol mode is the lowest level protocol mode in a plurality of protocol modes having various performance levels.
The method includes the steps of a) the first electronic device transmitting information to the second electronic device in accordance with the default base protocol mode of the transmission means and b) the first electronic device transmitting information to the second electronic device in accordance with the next higher level protocol mode. Also, the method includes the step of c) the first electronic device then transferring the data information to the second electronic device in accordance with the highest level protocol mode of the transmission means for which it received the transmitted information from the second electronic device.
In a still further aspect, the invention is a method for transferring data information from a first electronic device to a second electronic device, where the first electronic device communicates through a first I/O port according to a first protocol and the second electronic device communicates through a second I/O port according to a second protocol. The method includes the steps of a) determining the first protocol of communication by receiving protocol information from the first circuit and b) determining the second protocol of communication by receiving protocol information from the second circuit. The method further includes the step of c) programming a circuit connected between the first and second I/O ports to configure itself in response to the determined protocols so that the circuit can receive the data information according to the first protocol through the first I/O port and transmit the data information to the second electronic device through the second I/O port according to the second protocol to achieve a predetermined throughput rate of information between the first electronic device and the second electronic device.
REFERENCES:
patent: 4509113 (1985-04-01), Heath
patent: 5111423 (1992-05-01), Kopec, Jr. et al.
patent: 5293497 (1994-03-01), Free
patent: 5414707 (1995-05-01), Johnston et al.
Lowe Jay
Schuman Donald K.
Breene John
Robinson Greta L.
Storwick Robert M.
LandOfFree
Method and apparatus for parallel port interconnection does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for parallel port interconnection, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for parallel port interconnection will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2535868