Abstract: A test access port for an integrated circuit (or circuits) having a test register and a controller is provided. The controller enables the testability functions that have been selected by the test register. The test register performs the select function and the controller performs the enable function. An integrated circuit, having operation circuitry having nodes and external terminals for input and output of signals during normal operation, a test controller connected to at least a first one of said external terminals for receiving signals and for providing output signals during a test operation, and a test register for containing signals representative of selected tests to be performed connected to said test controller and at least a second one of said external terminals and responsive to said output signals of said test controller for enabling selected tests is provided.

Abstract: A data processing apparatus includes a three input arithmetic logic unit (230) that generates a combination of the three inputs that is selected by a function signal. Data registers (200) store the three data inputs and the arithmetic logic unit output. The second input signal comes from a controllable shifter (235). The shift amount is a default shift amount stored in a special data register, a predetermined set of bits of data recalled from a data register or zero. A one's constant source (236) is connected to the shifter (235) to supply a multibit digital signal of "1". This permits generating a second input signal of the form 2.sup.N, with N being the shift amount. The output of the shifter (235) may be stored independently of the arithmetic logic unit (230) result. The third input signal comes from a multiplexer (233) that selects between an instruction specified immediate field, data recalled from a data register or a mask input from a mask generator (239).

Abstract: An improved ring oscillator (10, 70) includes a first, second and third current starved inverters (12, 14, 16) coupled in a ring, a first fast inverter (40) coupled between the second and third current starved inverters (14, 16), and a second fast inverter (45) coupled between the third and first current starved inverters (14, 16). An output buffer (30) coupled to the ring provides an output periodic waveform.

Abstract: A data processing system on an integrated circuit 42 with microprocessor 1 and peripheral devices 60-61 is provided with an emulation unit 50 which allows debugging and emulation of integrated circuit 42 when connected to an external test system 51. Microprocessor 1 has in instruction execution pipeline that has several execution phases which involve fetch/decode units 10a-c and functional execution units 12, 14, 16 and 18. The pipeline of microprocessor 1 is unprotected so that memory access latency to data memory 22 and register file 20 can be utilized by system program code which is stored in instruction memory 23. Emulation unit 50 provides means for emulating the unprotected pipeline of microprocessor 1 and for rapidly uploading and downloading memories 22-23. Microprocessor 1 is operable to halt in response to an emulation event with partially completed instructions still in the execution pipeline.

Abstract: A microprocessor 1 has an instruction fetch/decode unit 10a-c, a plurality of execution units, including an arithmetic and load/store unit D1, a multiplier M1, an ALU/shifter unit S1, an arithmetic logic unit ("ALU") L1, a shared multiport register file 20a from which data are read and to which data are written, and a memory 22. Execution unit M1 has circuitry for multiplying two operands, shifting the resulting product and saturating the product if an overflow is detected in two execution phase of an instruction execution pipeline.

Abstract: A data processing apparatus (71) includes a data processor bus (103), the rotation register (208) and a register selection circuit. The rotation register (208) is embodied by a plurality of data registers (200) each having a plurality of equal bit groups. The number of bits within each bit group of each data register preferably equals the number N of data registers. The register selection circuit permits normal register reads and writes via the data processor bus. The register selection circuit permits special rotational data accesses. In a rotation read mode the register selection circuit selects noncontiguous bits from a predetermined position within each sections for each of the data registers for read access. In a rotation write mode the register selection circuit selects noncontiguous bits from a predetermined position within each sections for each of the data registers for write access. The data registers (200) are connected together in a loop (208).

Abstract: An active integrated circuit socket includes plural pin sockets receiving corresponding pins of an integrated circuit and plural socket pins making electrical contact with a printed circuit board. At least one active electronic component requiring electrical power for operation connects a pin sockets to a corresponding socket pin. The active electronic component may be a single ended input to differential output driver, a differential input to single ended output driver, a single ended to differential input/output transceiver or a voltage level shifter. These active components may include passive termination resistors. The single ended to differential transceiver may further include an enable input determining the direction of data transmission. This invention may be employed as an electronic system upgrade product including at least two active integrated circuit sockets connected via a flexible sheet including a plurality of electrical conductors connecting differential signal lines.

Abstract: In a method embodiment (10), the method operates a microprocessor (110), and the microprocessor has an instruction set. The method first (11) stores an identifier code uniquely identifying the particular microprocessor in a one-time programmable register. The method second (12) issues to the microprocessor an identifier request instruction from the instruction set. The method then, and in response to the identifier request instruction, provides (18) from the microprocessor an identifier code. Other circuits, systems, and methods are also disclosed and claimed.

Abstract: Circuits, systems, and methods relating to operating a computer system operable in a system manager mode (24). The method includes various steps. The first step (34) occurs during operation of the computer system (10) at a time other than start-up, and receives user power management data from a user of the computer system. The second step (38) stores the user power management data in memory space (30) accessible by the system management mode. The third step (40) accesses the user power management data from the memory space. Finally, the fourth step (42) controls at least one peripheral (14, 16, 18, 20) of the computer system in response to the accessed user power management data.

Abstract: A data processing system on an integrated circuit 42 with microprocessor 1 and peripheral devices 60-61 is provided with an emulation unit 50 which allows debugging and emulation of integrated circuit 42 when connected to an external test system 51. Microprocessor 1 has in instruction execution pipeline which has several execution phases which involve fetch/decode units 10a-c and functional execution units 12, 14, 16 and 18. The pipeline of microprocessor 1 is unprotected so that memory access latency to data memory 22 and register file 20 can be utilized by system program code which is stored in instruction memory 23. Emulation unit 50 provides means for emulating the unprotected pipeline of microprocessor 1 and for rapidly uploading and downloading memories 22-23. During emulation, the fetching of instructions from program memory can be halted.

Abstract: A semiconductor device (10) of the present invention has a gate (32) insulatively disposed above the substrate, source and drain regions (36, 38) disposed near the surface in the substrate adjacent opposite sides of the gate (32), and a field oxide region (26) disposed in the surface of the substrate surrounding the source and drain regions (36, 38) and defining an active moat region (20). The channel stop region (24) is disposed below the field oxide region (26) and is spaced from the active moat region (20) with a predetermined spacing.

Abstract: A microprocessor 10 has an internal program memory 23 and direct memory access (DMA) circuitry 100. Microprocessor 10 also has provisions for connecting to an external source of data via an external bus 73. Configuration circuitry 74 or 81 provides configuration parameters to DMA 100 when a reset signal 76 is deasserted. DMA 100 boot loads microprocessor 10 by transferring a block of data which contains an initial program from an external source to internal program memory after reset signal 76 is deasserted. At the completion of the boot load, microprocessor begins execution of the initial program.

Abstract: A memory store operation comes from one of a pair of registers selected by an arithmetic logic unit condition. An instruction logic circuit (250, 660) controls an addressing circuit (120) to store data in a first register into memory if a selected status bit has a first state and to store data in a second register associated with the first register into memory if the selected status bit has a second state in response to a register pair conditional store instruction. The bits may indicate a negative output of the arithmetic logic unit (230), a carry out signal, an overflow, or a zero output. The register pair conditional store instruction designates a particular one of the status bits to control the conditional store. The instruction logic circuit (250, 660) substitutes the selected status bit for a least significant bit of the register number. Thus memory store is from the first register if the status bit is "1" and is from the second register if the status bit is "0".

Abstract: A data processing system on an integrated circuit 42 with microprocessor 1 and peripheral devices 60-61 is provided with an emulation unit 50 which allows debugging and emulation of integrated circuit 42 when connected to an external test system 51. Microprocessor 1 has in instruction execution pipeline which has several execution phases which involve fetch/decode units 10a-c and functional execution units 12, 14, 16 and 18. The pipeline of microprocessor 1 is unprotected so that memory access latency to data memory 22 and register file 20 can be utilized by system program code which is stored in instruction memory 23. Emulation unit 50 provides means for emulating the unprotected pipeline of microprocessor 1 and for rapidly uploading and downloading memories 22-23. Emulation unit 50 operates in a manner to prevent extraneous operations from occurring which could otherwise affect memories 22-23 or peripheral devices 60-61 during emulation.

Abstract: A microprocessor 1 has an instruction fetch/decode unit 10a-c, a plurality of execution units, including an arithmetic and load/store unit D1, a multiplier M1, an ALU/shifter unit S1, an arithmetic logic unit ("ALU") L1, a shared multiport register file 20a from which data are read and to which data are written, and a memory 22. These units form an instruction execution pipeline that operates without interlocks so that nestable delayed branch instructions are provided. The control circuitry for the instruction execution pipeline is operable to begin processing a second branch instruction having a second target address on a pipeline phase immediately after beginning processing of a first branch instruction having a first target address.

Abstract: A microprocessor operates in response to microinstructions stored in a read only memory. A patch table stores a indication of patch microinstructions stored in cache memory. This cache memory caches data and/or macroinstructions for the microprocessor. Each new microaddress is compared with the patch table entries. If there in no match, then a multiplexer selects the microinstruction recalled from that microinstruction address within the microinstruction read only memory. If there is a match, then a corresponding patch microinstruction is recalled from the cache memory. The multiplexer selects this patch microinstruction. The microprocessor operates under the control of the selected microinstruction. This technique enables a fix of faulty microinstructions in the field, by supplying the computer user with the patch microinstructions. Using a portion of the cache memory to store the patch microinstructions eliminates any problem with specifying too large or too small a memory for patch microinstructions.

Abstract: An emulation device which enables a functional circuit to support self emulation. A serial scan testability interface has at least first, second and third scan paths, said first scan path being provided for applying digital information to the functional circuit for use in emulation of the functional circuit. A first state machine connected to said second scan path has a first state selected from among a first set of states. A second state machine connected to said third scan path has a second state selected from among a second set of states. The emulation device performs an emulation command based on a combined first state of said first state machine and second state of said second state machine. The state of the first state machine indicates a primary portion of the emulation command denoting an emulation command class. The state of the second state machine indicates a secondary portion of the emulation command consisting of a subtype within the emulation command class.

Abstract: A microprocessor (10) comprising a central processor unit core (12) operable to write information during a write cycle and a cache circuit (18) coupled to the central processor unit core and operable to evict information. The microprocessor further includes a combined storage queue (16) coupled to the central processor unit core and to the cache circuit. The combined storage queue includes a set of logical storage blocks (22c) which is operable to store both information written by the central processor unit core and information evicted by the cache circuit. Other circuits, systems, and methods are also disclosed and claimed.

Abstract: There is disclosed a multi-processor system arranged, in one embodiment, as an image and graphics processor. The processor is structured with several individual processors all having communication links to several memories. The individual processors can, on a cycle by cycle basis, be grouped in any configuration to run in synchronism (but from different instruction streams) with the other processors in that group. More than one such synchronized group can be formed concurrently. A crossbar switch serves to establish the processor memory links and the entire image processor, including the individual processors, the crossbar switch and the memories are contained on a single silicon chip.

Abstract: An address generating circuit of simple configuration for repeating a selected block of instructions is provided. An instruction address maintained by program counter 72 is compared to register 76 that holds the address of the end of the selected block of instructions. When the end address is detected, the program counter is loaded with a starting address of the block of instructions, which is stored in register 80. Block repeat count register 86 maintains a repeat count. Zero detection circuit 70 delays decrements of register 86 by a number of clock cycles that is equivalent to a pipeline depth for instruction prefetching of a processor connected to program counter 72. The zero detection circuit 70 outputs a loop-end control signal which controls a selector to selectively provide an incremented address or the start address to the program counter. By delaying decrements of register 86, the state of the repeat count is correctly maintained when the processor pipeline is flushed during an interrupt.