摘要:
Apparatus for testing an integrated circuit, the integrated circuit comprising a plurality of semiconductor memory cells connected by a common word-line, each memory cell comprising: respective first and second transistors in cross-coupled arrangement to form a bistable latch, the drain of the first transistor representing a respective first node for storing a high or low potential state and being connected to a respective first semiconductor arrangement for replacing charge leaked from the first node and being connected to a respective first switching means, activatable by the common word-line, for coupling the respective first node to a respective first bit-line, the drain of the second transistor representing a respective second node for storing a high or low potential state and being connected to a respective second semiconductor arrangement for replacing charge leaked from the respective second node and being connected to a respective second switching means, activatable by the common word line, for coupling the second node to a respective second bit-line; and a respective individual gate arrangement having an output, and inputs connected to the respective first and second bit-lines, and being arranged to provide an output of a first type when the respective first and second bit lines are both within a low potential range, and otherwise provide an output of a second type; and the apparatus comprising a common gate arrangement having an output, and inputs connected to the outputs of the individual gate arrangements, the common gate arrangement being arranged to provide an output of a first type when the inputs are all of the same type, and otherwise provide an output of a second type.
摘要:
Call frame information is used by debugging software. It records how to restore the parent stack frame at any point during execution of a program. It is normally generated during compilation and stored in the executable in a compressed format, consisting of sequences of instructions that describe how the current call frame changes during execution of each function. Described herein is a means of generating call frame information at link time, using linker macro calls generated by a small set of assembler macros.
摘要:
A system comprising first input means for receiving a transport stream from an external source, second input means for receiving an input from a memory, means for connecting the first and second input means to an interface which is arranged to provide an output stream to a decoder. The second input means is arranged to provide an output to the interface in such a form that the interface does not distinguish between the output from the first and second input means.
摘要:
A graphic processor having an index processing unit for pre-processing a list of vertices making up a three-dimensional image. The method of pre-processing comprising the following steps. Firstly, decomposing the three-dimensional image into a plurality of primitive elements each defined by a set of vertices, each vertex comprising vertex information stored in a vertex storage area and addressable by a vertex index. Then receiving said vertex indices and creating a set of unique indices identifying a batch of vertices and loading only the vertices corresponding to said unique indices into the vertex storage area. Finally creating transformed primitive elements from transformed vertex information addressed in the vertex storage area using the unique indices.
摘要:
A digital frequency divider includes phase control of the output signal in increments of whole or half cycles of the input frequency. Whole cycle phase control is achieved by varying (logically or physically) the tap off point of a shift register loaded with a bit pattern for appropriate division. Half cycle phase changes is achieved by a multiplexer selecting one of two signals every half cycle.
摘要:
For a packet identification (PID) contained at a variable possible location which comprises part only of a 32-bit packet header, a corresponding DES key value is located. A table (10) stored in memory contains for each DES key (12) (i) a packet header (14) comprising 32 bits with a possible PID of e.g. 12, 9 or 8 bits contained at a defined location and with zero values elsewhere, and (ii) a mask value (16) also comprising 32 bits with ones contained at the said defined location of the PID and zeros elsewhere. The table is divided into regions (18) for respective packet format types. An incoming packet header at an input (22) is combined (26) with a first one of the mask values from the table so as to provide a combined value which consists of the value held in the input packet header at the defined location and zeros elsewhere. This combined value is compared (36) with the corresponding packet header stored in the table. If they are not equal, the combining and comparison is repeated for the next row of the table. If they are equal, the corresponding DES key value is read (32) from the table and provided as an output (38). The system can cope with variable PID formats within the packet header without alteration to the hardware but merely with re-programming of the table contents.
摘要:
A stackable module for a processor system is described. The module comprises a support plate with a set of topside circuit components mounted to its topside, and topside and underside connectors. The module can be stacked with other such modules and are provided with conductive tracks which are arranged to convey transport stream data and transport stream control signals between modules in a stack. The invention also provides a stack of such modules in a processor system.
摘要:
A method is described for distinguishing between an input or output signal on a bi-directional pin of a model of a hardware circuit. The method comprises the steps of for a bi-directional pin of said model applying signals to said pin at a reduced drive strength such that a driven signal on said pin will be superimposed over the applied signal, and comparing the drive strength on the bi-directional pin and responsive to said comparison determining whether the bi-directional pin is an input or output.
摘要:
A ratio logic gate has a current mirror (20) controlled by the pull-down transistors (10-13) and supplying a half size pull-down transistor (23). When one or more of the input pull-down transistors (10-13) is on, the mirror current overcomes the output pull-down transistor (23) to provide a high potential output. Process tolerances between p and n type devices is thus avoided.
摘要:
A flip-flop circuit comprises a pair of cross-coupled inverters, each of which has a respective FET connected in series between it and the reference terminal, each inverter driving a transistor of an output inverter.