摘要:
A controlled delay path inserts a selected delay into a clock distribution circuit to create a total clock delay that is equal to an integer number of clock cycles relative to a reference dock signal or which produces a selected phase relationship to the reference dock signal. The delay path correction of the invention is particularly useful in circuits having a wide range of possible system clock frequencies or having programmable routing of clock signals, and therefore a wide range of operating delays. A reference clock signal is directed to a range of selectable voltage controlled delay elements by a phase detector that receives the reference clock signal and a feedback signal, and that produces an error voltage which adjusts the voltage controlled delay elements to produce an output clock signal. Additional selectable delays may be included that create offset options and allow selection of a leading, lagging, or in-phase reference dock/output clock relationship. In one embodiment both the positive and negative edges of a clock signal are corrected. As another feature, if correction is consistently in the same direction an error flag is generated.
摘要:
A self-addressing memory device is provided that can provide blocks of data starting from more than one initial location in the device, and may have the option of reading in either direction. This memory device can efficiently store multiple bitstreams, which may be of different sizes, that are used to configure one or more configurable logic devices. Each stored bitstream can be accessed in any order. In one embodiment, the configurable logic device is a Field Programmable Gate Array ("FPGA"). In one embodiment, the memory device is a Read-Only Memory ("ROM") that is either read up from all zeros or down from all ones. In one embodiment, the ROM includes a bidirectional chip enable chain that permits cascading multiple ROMs.
摘要:
A pipeline frame full detection circuit. The present invention is operable within a system that loads configuration data into an integrated circuit (IC) using a serial data stream and transfer mechanism. Configuration data is transferred into the IC in sequential frames of a specified size for a given IC. The first bit of the configuration data contains a frame full indicator. The configuration data is transferred into a shift register circuit and the last bit position(s) of the shift register circuit, in addition to being stored in the shift register circuit, are shifted along a special frame full pipeline to a control unit. The control unit, upon detecting the frame full indicator, asserts a parallel write command that causes the data of the shift register circuit to be parallel transferred to a receiving column of memory. New configuration data can then be serially shifted into the same shift register circuit after a reset signal. By shifting the frame full indicator through a pipeline, the propagation delay required for the frame full indicator to reach the control unit is significantly reduced. It is this propagation delay that limits the transfer rate of the configuration data into the IC. Therefore, the present invention advantageously reduces this limiting factor.
摘要:
A system of modifiable group skeletal formatting of persistent objects. The object oriented framework provides abstract classes for persistent object grouping and storage. Abstract classes define the interfaces and allow implementation details to be deferred until runtime. The implementor creates subclasses overriding the abstract methods and implementing specific group skeletal formats. Multiple formats can be defined and object instance variables set to indicate which formatter to use. The defined interfaces and methods allows interchangeable substitution of group formatters.
摘要:
Power or ground voltage can fluctuate when many high capacitance terminals of an integrated circuit device move simultaneously from one logic state to another. This occurs particularly after release of a global high impedance state of output buffers where output signals have been passively driven to a selected logic state. To prevent supply and ground voltage variations, the buffers are provided with means for operating in a slow response (high skew) mode. A slew rate control circuit moves the buffer to slow response mode in response to the high impedance signal. When the slew rate control circuit receives a signal ending the high impedance state of the buffer, it applies a delay to this signal, and after the delay time allows the buffer to move to a fast response mode. The slow buffer response and resulting slow voltage change when high capacitance terminals move to a new logic state prevents fluctuation of power or ground voltage in response to simultaneous switching of many terminals.
摘要:
Expert system supported interactive product selection and recommendation. The invention assists an agent to interact with a customer and to provide selection and recommendation of available products and/or services that offer a workable solution for the customer. The invention allows for the use of agents of varying skill levels, including relatively low skill level, without suffering deleterious performance. From certain perspectives, an expert system employed using various aspects of the invention allows the agent to provide real time interaction with a customer and to provide a real time recommended solution to that customer. Many traditional approaches dealing in complex industries require that agent's have a high degree of skill and expertise. The invention allows even a novice agent to service a customer's needs without requiring a high skill level or up-front training that is often at the expense of the provider seeking to market its products and/or services.
摘要:
An expert system adapted dedicated Internet access guidance engine. The invention allows an agent to interact with a customer and to provide selection and recommendation of data network products and/or services for the customer. The invention allows for the use of agents of varying skill levels, including relatively low skill level, without suffering deleterious performance. The dedicated Internet access guidance engine is operable to perform selection and rating of Internet access products and/or services to provide a solution that meets the needs of a customer. The dedicated Internet access guidance engine is operable to select recommended solutions from among a number of potential solutions that may include compatible solutions. The dedicated Internet access guidance engine is one of the underlying engines within the expert system that allows the agent to provide real time interaction with a customer and to provide a real time recommended solution to that customer.
摘要:
A method of communicating encrypted configuration data between a programmable logic device (PLD) and a storage device is included in one part of the invention. The method includes the following steps. Transmit encrypted configuration data stored in a storage device to the PLD. Decrypt the encrypted configuration data to generate a copy of the configuration data in the PLD. Configure the PLD using the copy of the configuration data. In one embodiment, the PLD transmits a key to the storage device. In another embodiment the key is separately entered into the storage device and the PLD and never transmitted between the PLD and the storage device. In another embodiment, the key is entered only into the PLD. The key is used to encrypt the configuration data.
摘要:
A multi-state input drive structure is provided to forward externally generated high and low input signals, as well as to receive at least a third, internally generated, comparatively weak signal, preferably an oscillating signal, which triggers a third internally forwarded signal when neither of the high and low input signals is received. The inventive circuit drives three internally forwarded output signals from a single external signal source. Since this circuit may be duplicated for every pin on a device for which two cycle delays do not affect performance, availability of a third input state on N inputs allows 3.sup.N input codes as opposed to 2.sup.N for the conventional "high" and "low" levels normally available.
摘要:
A self-addressing memory device is provided that can provide blocks of data starting from more than one initial location in the device, and may have the option of reading in either direction. This memory device can efficiently store multiple bitstreams, which may be of different sizes, that are used to configure one or more configurable logic devices. Each stored bitstream can be accessed in any order. In one embodiment, the configurable logic device is a Field Programmable Gate Array ("FPGA"). In one embodiment, the memory device is a Read-Only Memory ("ROM") that is either read up from all zeros or down from all ones. In one embodiment, the ROM includes a bidirectional chip enable chain that permits cascading multiple ROMs.