Abstract: A full-scan latch is provided that may be used to incorporate design for test functionality in an integrated circuit. The full-scan latch includes a shadow latch, a multiplexer, and a slave latch. The full-scan latch has a test mode and a normal mode. When in the normal mode, the device operates as a transparent latch, passing a data input to its output. When in test mode, the device is operable to pass scan data down a scan chain and to inject scan data into the data path.

Abstract: A supply switch circuit is provided for implementing a switchable on-chip high voltage supply. A stack of transistors is coupled between an on-chip high voltage supply and a circuit node. A control signal is coupled to the stack of transistors for selectively switching the high voltage supply to the circuit node. The control signal is coupled to a voltage divider included with the stack of transistors to limit a maximum node voltage within the stack of transistors.

Abstract: Techniques for adaptively scaling voltage for a processing core are described. In one scheme, the logic speed and the wire speed for the processing core are characterized, e.g., using a ring oscillator having multiple signal paths composed of different circuit components. A target clock frequency for the processing core is determined, e.g., based on computational requirements for the core. A replicated critical path is formed based on the characterized logic speed and wire speed and the target clock frequency. This replicated critical path emulates the actual critical path in the processing core and may include different types of circuit components such as logic cells with different threshold voltages, dynamic cells, bit line cells, wires, drivers with different threshold voltages and/or fan-outs, and so on. The supply voltage for the processing core and the replicated critical path is adjusted such that both achieve the desired performance.

Abstract: An interface circuit according to one embodiment of the present invention includes a clock signal, a first phase locked loop coupled to the clock signal line and generating a reference clock signal, a second phase locked loop receiving the reference clock signal, and in accordance therewith, generating one or more phase shifted reference clock signals, and a data transceiver circuit coupled to receive at least one of the clock signal, the reference clock signal, or one or more of the phase shifted reference clock signals to control the flow of data between a first circuit and a second circuit. An interface circuit according to one embodiment of the invention can be used advantageously for controlling the flow of data between a CPU and an external memory.

Abstract: An integrated circuit includes multiple power domains. Supply current switch circuits (SCSCs) are distributed across each power domain. When a signal is present on a control node within a SCSC, the SCSC couples a local supply bus of the power domain to a global supply bus. An enable signal path extends through the SCSCs so that an enable signal can be propagated down a chain of SCSCs from control node to control node, thereby turning the SCSCs on one by one. When the domain is to be powered up, a control circuit asserts an enable signal that propagates down a first chain of SCSCs. After a programmable amount of time, the control circuit asserts a second enable signal that propagates down a second chain. By spreading the turning on of SCSCs over time, large currents that would otherwise be associated with coupling the local and global buses together are avoided.

Abstract: An interface circuit according to one embodiment of the present invention includes a clock signal, a first phase locked loop coupled to the clock signal line and generating a reference clock signal, a second phase locked loop receiving the reference clock signal, and in accordance therewith, generating one or more phase shifted reference clock signals, and a data transceiver circuit coupled to receive at least one of the clock signal, the reference clock signal, or one or more of the phase shifted reference clock signals to control the flow of data between a first circuit and a second circuit. An interface circuit according to one embodiment of the invention can be used advantageously for controlling the flow of data between a CPU and an external memory.

Abstract: An interface circuit according to one embodiment of the present invention includes a clock signal, a first phase locked loop coupled to the clock signal line and generating a reference clock signal, a second phase locked loop receiving the reference clock signal, and in accordance therewith, generating one or more phase shifted reference clock signals, and a data transceiver circuit coupled to receive at least one of the clock signal, the reference clock signal, or one or more of the phase shifted reference clock signals to control the flow of data between a first circuit and a second circuit. An interface circuit according to one embodiment of the invention can be used advantageously for controlling the flow of data between a CPU and an external memory.

Abstract: A supply switch circuit is provided for implementing a switchable on-chip high voltage supply. A stack of transistors is coupled between an on-chip high voltage supply and a circuit node. A control signal is coupled to the stack of transistors for selectively switching the high voltage supply to the circuit node. The control signal is coupled to a voltage divider included with the stack of transistors to limit a maximum node voltage within the stack of transistors.

Abstract: A method of designing a circuit includes annotating relative positions of instantiated hierarchical macro cells, which include two or more instantiated standard cells. The relative positions of individual instantiated standard cells may also be annotated. Relative positions of instantiated hierarchical macro cells and individual instantiated standard cells may be altered to form a more compact standard cell configuration. Pin positions may also be annotated by relative position. Relative pin positions may be altered to promote dense signal line routing within the standard cell design. The relative positions of the instantiated hierarchical macro cells and individual instantiated standard cells are converted to absolute grid position locations to form a grid assigned circuit. The grid assigned circuit is then routed.

Abstract: An interface circuit according to one embodiment of the present invention includes a clock signal, a first phase locked loop coupled to the clock signal line and generating a reference clock signal, a second phase locked loop receiving the reference clock signal, and in accordance therewith, generating one or more phase shifted reference clock signals, and a data transceiver circuit coupled to receive at least one of the clock signal, the reference clock signal, or one or more of the phase shifted reference clock signals to control the flow of data between a first circuit and a second circuit. An interface circuit according to one embodiment of the invention can be used advantageously for controlling the flow of data between a CPU and an external memory.

Abstract: A method for forwarding data within a pipeline of a pipelined data processor having a plurality of execution pipeline stages where each stage accepts a plurality of operand inputs and generates a result. The result generated by each execution pipeline stage is selectively coupled to an operand input of one of the execution pipeline stages.

Abstract: A method for forwarding data within a pipeline of a pipelined data processor having a plurality of execution pipeline stages where each stage accepts a plurality of operand inputs and generates a result. The result generated by each execution pipeline stage is selectively coupled to an operand input of one of the execution pipeline stages.

Abstract: A processor including a plurality of execution pipeline stages where each stage accepts a plurality of operand inputs and generates a result. A pipefile having at least the same number of entries as the number of execution pipeline stages is included in the processor. A pointer register is associated with each execution pipeline stage. A value is stored in at least one of the pointer registers, the value indicating a particular one of the entries in the pipefile.

Abstract: A processor including a plurality of execution pipeline stages where each stage accepts a plurality of operand inputs and generates a result. A pipefile having at least the same number of entries as the number of execution pipeline stages is included in the processor A pointer register is associated with each execution pipeline stage. A value is stored in at least one of the pointer registers, the value indicating a particular one of the entries in the pipefile.

Abstract: A fully associative address translator which includes a number of entries, each of said number of entries translating a received effective address into a real address, each received effective address including a segment identifier and a page identifier. Each of the entries within the fully associative address translator includes a first translation from an effective address segment identifier into a virtual address segment identifier and a second translation from a virtual address page identifier to a real address page identifier.

Abstract: An address translator (126) translates addresses, acting like a register file or a table, as necessary. The address translator contains a number of entries for matching an input address to a stored tag. An entry outputs a stored translated address if its stored tag matches the input address. A decoder (138) selects a particular entry in which to store an input translated address when the address translator operates as a register file. In these cases, a register number is also stored in the particular entry's as the entry's tag. Later, when it is necessary to read the particular entry, the register number is compared to each entry's tag to find a match. The disclosed address translator is compatible with both hardware and software refill algorithms ("tablewalks") without impacting its critical read speed path.

Abstract: A sense amplifier (10) has a pair of cross-coupled latches (12, 14, 16, 18) connected between a first voltage supply (V.sub.DD) and the sources of two transistors (20, 22). The gates of the two transistors receive a voltage differential to be sensed. The drains of the two transistors are coupled to a second voltage supply (V.sub.SS) through an enabling transistor (24). The resulting sense amplifier is fast, small, and relatively simple to construct.