Abstract:
PROBLEM TO BE SOLVED: To provide an identification device and its method for identifying a microprocessor during operation. SOLUTION: The microprocessor 10 reads out microprocessor ID data from a read-only memory 31 storing the microprocessor ID data for identifying itself in response to identification command, and stores the same in registers 20, 22 which can be selectively read out by a programmer. When the microprocessor 10 is identified, an appropriate function for the specific microprocessor can be enabled, and a work around program can be installed. The implementation of ID command in the microprocessor not having the identification device is inhibited. COPYRIGHT: (C)2006,JPO&NCIPI
Abstract:
A dual instruction decoder issues two instructions in parallel within a single clock cycle if there are no register dependencies between the instructions, and if both instructions fall within a predetermined subset of the complete instruction set. A first pipeline executes any instruction issued from the full instruction set, while a second pipeline only executes a predetermined subset of instructions determined by principles of locality. A register dependency checker determines whether the designation register of a first instruction is used during the execution of a second instruction in an instruction sequence. When both instructions are within the subset and there are no dependencies, the first and second instructions can be issued in parallel in the first and second pipelines.
Abstract:
A data processor (104) is described. The data processor (104) is capable of decoding and executing a first instruction (212) of a first instruction set and a second instruction (213-219) in a second instruction set wherein the first instruction (212) and the second instruction (213-219) originate from a single computer program (210, 211). Alternatively, the data processor (104) can also execute a first instruction (212) of a first instruction set in a first instruction set mode, receive a first interruption indication in the first instruction set mode, service the first interruption indication in a second instruction set mode, return to the first instruction set mode, receive a second interruption indication in the first instruction set mode, and service the second interruption indication in the first instruction set mode.
Abstract:
An interleaved cache is used for multiple data accesses per clock in a microprocessor. The cache includes a storage array having multiple banks of single-ported memory cells for storing data, a bank selector for selecting banks in the storage array simultaneously according to the multiple data accesses, and a datapath for transfering data between execution units in the microprocessor and the storage array. The cache of the present invention also includes contention logic for prioritizing the multiple data accesses when multiple data accesses are to be same bank.
Abstract:
A multi-level identification apparatus and method for providing at least two types of identification information, including a first type for identifying the origin of a microprocessor and the number of levels of identification information available, and a second type for identifying a family, a model, a stepping ID, and features of a microprocessor. The apparatus includes a first memory element for storing an indicia string that identifies the origin of the microprocessor. The apparatus also includes a second memory element for storing other microprocessor ID data including data fields for specifically identifying the microprocessor. The apparatus includes control logic for executing an ID instruction that reads the indicia string or the microprocessor ID data, dependent upon a preselected type. Whichever identification information is read, it is stored in one or more general purpose registers for selective reading by a programmer. The method is available at any time while the microprocessor is operating.
Abstract:
An apparatus and method for identifying a microprocessor uses a read-only memory for storing microprocessor ID data, and control logic for executing an ID instruction that transfers the microprocessor ID data from the read-only memory to a register that can be selectively read by a programmer. The identification apparatus and method also includes an ID flag indicating availability of the ID instruction in the microprocessor, and a test flag program for testing the ID flag to determine whether or not to execute the ID instruction.
Abstract:
A microprocessor can be operated in an external command mode or a conventional processor-driven mode. A multiplexer 18 selects which instruction path, external or processor driven, is actually supplied to the execution unit 20. Using the external command mode, the user can examine and modify registers, memory, and I/O space without otherwise affecting their contents and, because direct access is provided into the execution unit, there is no implicit updating that would otherwise affect the state of the processor and require saving to an alternate memory. A conventional test access port 12 for implementing the external mode is modified to include an instruction register 36, a data register 38, and control logic 40. Mode selection is carried out by an external pin 30, an external command, and a debug exception. For ascertaining if the circuit is in the external command mode, an acknowledge pin 86 is provided to indicate when the execution unit is ready to accept an instruction.