Electronic digital logic circuitry – With test facilitating feature
Reexamination Certificate
2000-05-01
2001-10-09
Tokar, Michael (Department: 2819)
Electronic digital logic circuitry
With test facilitating feature
C326S014000, C326S009000
Reexamination Certificate
active
06300787
ABSTRACT:
THE FIELD OF THE INVENTION
The present invention relates generally to observing communications between a pair of electrical components within a system, and more specifically to observing a bi-directional communication link between two integrated circuits for the purposes of analyzing and debugging the system.
BACKGROUND OF THE INVENTION
The sophistication of a present-day electronic system is a result of complex functions handled by integrated circuits making up the electronic system. Within a single silicon chip or wafer, numerous integrated circuits are fabricated. Each integrated circuit may comprise many millions of transistors, including associated diodes, resistors, and capacitors, interconnected to form complex electronic systems capable of performing various functions.
Semiconductor integrated circuits comprise the majority of electronic circuits in computers and other digital electronic products. Integrated circuits can be configured, for example, as a central processing unit (CPU), a programmable logic array (PLA), an application specific integrated circuit (ASIC), or a digital signal processor (DSP). Both the sophistication and speed of operation of these integrated circuits has rapidly increased due to improvements in integrated circuit manufacturing technologies resulting in smaller and faster devices.
Once a computer or another digital electronic product is manufactured, it is important to test various aspects of the system to verify proper operation. For example, the interconnection between two integrated circuits must be verified. In addition, it must be verified that a specific integrated circuit is operating properly. In most circumstances, the communication between two integrated circuits is facilitated by a data bus, which includes first and second communication links. The first and second communication links provide bi-directional communication between the first and second integrated circuits such that communication in a first direction is provided by a first communication link while communication in a second direction is provided by the second communication link.
In order to test or “debug” systems having bi-directional communication links between two integrated circuits, prior art analyzation systems included an analyzing device, such as a logic analyzer or an oscilloscope. The analyzing device includes two leads which are electrically connected to the first and second communication links. During a testing operation of the system, the analyzing device observes the data being communicated between the first and second integrated circuits via the first and second communication links. This information is then compared to information which is expected to be observed between the first and second integrated circuits. If the two sets of information coincide, it is assumed that the communication links and adjacent integrated circuits are properly installed and functioning. Conversely, if the two sets of information do not coincide, it is assumed that a portion of the system is not operating as designed.
Another prior art embodiment for testing and debugging a system includes dedicating numerous pins within an integrated circuit for repeating or copying a communication link, which may be observed without disrupting normal operation of the system. However, this approach is very costly in terms of chip pinout, in that numerous additional pins are dedicated solely for test purposes, rather than operational purposes.
The speed with which computers and electronic devices operate has drastically increased in the recent past. For example, computers are capable of operating at frequencies in the high megahertz to gigahertz range. However, the technology relating to analyzing devices such as logic analyzers or oscilloscopes, has not increased in such magnitude. Rather, most analyzing devices are not capable of operating at frequencies in the mid megahertz to low gigahertz range. Thus, interconnecting an analyzer device directly to communication lines within a present day electronics system will disrupt and disturb the normal operation of the system, perhaps rendering the system inoperable. Therefore, there is a need for a system and method which will permit observation and debugging of bi-directional information transmitted on first and second communication links between first and second integrated circuit such that the overall performance of the system will not be inhibited and that a minimal number of pins are used.
SUMMARY OF THE INVENTION
The present invention provides a system and method for observing bi-directional information transmitted on a first and a second communication link between a first and a second integrated circuit to determine proper operation of the communication links and integrated circuits such that the performance of the overall system is not inhibited.
One embodiment of the invention includes a system for observing bi-directional information transmitted on a first and a second communication link between a first data port of a first integrated circuit and a first data port of a second integrated circuit. The system includes a second data port of the second integrated circuit, the second data port electrically coupled to the first communication link at the first data port of the second integrated circuit. The second data port of the second integrated circuit is capable of electrical connection with an analyzing device, such as a logic analyzer or an oscilloscope. A third data port of a second integrated circuit is electrically coupled to the second communication link at the first data port of the second integrated circuit. A third communication link electrically connects the third data port of the second integrated circuit to a first data port of a third integrated circuit. A second data port of the third integrated circuit is electrically coupled to the first data port of the third integrated circuit, a second data port capable of electrical connection with the analyzing device.
In one embodiment of the invention, the second data ports of the second and third integrated circuits are dedicated debugging ports, solely for facilitating an analyzing function. In another embodiment of the invention, the debugging ports of the second and third integrated circuits may be standard data ports capable of facilitating the communication of data between the second and third integrated circuits, respectfully, and other electrical components or integrated circuits of the overall system.
In another embodiment of the present invention, the second ports of the second and third integrated circuits, while being dedicated debugging ports, may each include in the range of approximately 50-250 data pins.
The present invention also includes a method of observing bi-directional information transmitted on a first and a second communication link electrically connected between a first integrated circuit and a second data port of a second integrated circuit. The method includes electrically coupling the first communication link from the first data port of the second integrated circuit to a second data port of the second integrated circuit, while the second communication link is electrically coupled from the first data port of the second integrated circuit to a third data port of the second integrated circuit. Further, a third communication link is electrically coupled from a third data port of the second integrated circuit to a first data port of a third integrated circuit, which in turn is electrically coupled to a second data port of the third integrated circuit. The first communication link at the second data port of the second integrated circuit and the second communication link at the second data port of the third integrated circuit can be observed by an analyzing device, such as a logic analyzer or an oscilloscope, electrically coupled to the second data ports of the second and third integrated circuits.
In one embodiment of the invention, the second data ports of both the second and third integrated circuits are each dedicated debugging ports. The dedicated debugging p
Shaeffer Ian P.
Snyder Robert D.
Hewlett--Packard Company
Tokar Michael
Tran Anh Q.
LandOfFree
System and method for observing information transmitted... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with System and method for observing information transmitted..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and System and method for observing information transmitted... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2573556