摘要:
A multiprocessor system includes a number of sub-processor systems, each substantially identically constructed, and each comprising a central processing unit (CPU), and at least one I/O device, interconnected by routing apparatus that also interconnects the sub-processor systems. A CPU of any one of the sub-processor systems may communicate, through the routing elements, with any I/O device of the system, or with any CPU of the system. The CPUs are structured to operate in one of two modes: a simplex mode in which the two CPUs operate independently of each other, and a duplex mode in which the CPUs operate in lock-step synchronism to execute each instruction of identical instruction streams at substantially the same time. Communications between I/O devices and CPUs is by packetized messages. Interrupts from I/O devices are communicated from the I/O devices to the CPUs (or from one CPU to another CPU) as message packets. CPUs and I/O devices may write to, or read from, memory of a CPU of the system. Memory protection is provided by an access validation method maintained by each CPU in which CPUs and/or I/O devices are provided with a validation to read/write memory of that CPU, without which memory access is denied.
摘要:
A multiprocessor system includes a number of sub-processor systems, each substantially identically constructed, and each comprising a central processing unit (CPU), and at least one I/O device, interconnected by routing apparatus that also interconnects the sub-processor systems. A CPU of any one of the sub-processor systems may communicate, through the routing elements, with any I/O device of the system, or with any CPU of the system. Communications between I/O devices and CPUs is by packetized messages. Interrupts from I/O devices are communicated from the I/O devices to the CPUs (or from one CPU to another CPU) as message packets. CPUs and I/O devices may write to, or read from, memory of a CPU of the system. Memory protection is provided by an access validation method maintained by each CPU in which CPUs and/or I/O devices are provided with a validation to read/write memory of that CPU, without which memory access is denied.
摘要:
A circuit and method for preventing an oscillator from oscillating above a first predetermined frequency or below a second predetermined frequency. The present invention may comprise (a) a clock generation circuit configured to generate an output clock signal in response to (i) a reference clock, (ii) one or more control signals and (ii) a reset signal and (b) a control circuit configured to generate said reset signal in response to said one or more control signals.
摘要:
A bandgap reference circuit includes an amplifier configured to provide an output voltage dependent upon voltages appearing at an inverting input and a non-inverting input. The bandgap reference circuit also includes a first transistor coupled between the non-inverting input and a circuit ground reference, and a first resistor coupled to the inverting input. The bandgap reference circuit also includes a number of second transistors coupled in parallel between the circuit ground reference and the first resistor. At least a portion of the second transistors are connected to the first resistor through a plurality of programmably selectable switches.
摘要:
A differential delay cell is provided herein that not only receives a pair of differential input values, but also receives a pair of differential control values for delaying the differential input values to produce a pair of differential output values. As such, a delay cell is provided, which is truly differential, and therefore, capable of demonstrating a significant improvement in noise performance. The differential delay cell of the present invention also demonstrates high frequency stability around the center frequency, constant gain and increased tuning range capabilities. In this manner, the differential delay cell may be used in PLL or DLL designs as part of a low noise VCO or a low noise delay line, respectively.
摘要:
The present invention includes a circuit, system, and method for avoiding a non-desired output from a latch, and a selector circuit that is programmable to select an input to a prioritizer which, based on that input, sets the latch output to avoid a non-desired state regardless of the latching input values. The embodiments described herein are useful in forming a non-clocked latch that employs set and reset inputs, and thus, may be an SR latch. The SR latch is envisioned having either MOSFET or bipolar transistors, and can be employed either having only NMOS transistors, only PMOS transistors, or CMOS transistors. The latch also includes an improved selector circuit that is easily programmed to configure the latch in either a set-dominant, a reset-dominant, or a memory-dominant configuration based solely on the voltage values fed to the latch by the selector circuit. As such, the selector circuit of the present invention embodies an improved programmability over previous circuits.
摘要:
A circuit and method are provided for ensuring a non-desired output state of a latch or flip-flop cannot be produced. The latch can be configured as a set dominant, reset dominant, or memory dominant circuit by simply placing programmed voltage values on select transistors of the latch. The programmed values will cause either the set input, the reset input, or both set and reset inputs to have a complimentary effect on the output signals even though the set and reset inputs are at the same logic level. The set, reset, and memory dominant circuit is identical in structure; however, the set, reset, and memory dominant features are derived solely by placing programmed values on corresponding transistors within the identical structure. A generic latch circuit can, therefore, be said to operate in one of three dominant ways depending on the programmed values chosen by a selector and fed to a prioritizer.