摘要:
A pipeline control system for implementing a virtual architecture having a complex instruction set is distributed over RISC-like semi-autonomous functional units in a processor. Decoder logic fetches instructions of the target architecture and translates them into simpler RISC-like operations. These operations, each having an associated tag, are issued to the functional units. Address processing unit computes addresses of the instructions and operands, performs segment relocation, and manages the processor's memory. Operations are executed by the units in a manner that is generally independent of operation processing by the other units. The units report termination information back to the decoder logic, but do not irrevocably change the state of the machine. Based on the termination information, the decoder logic retires normally terminated operations in order. Thus, the functional units enable multiple operations to be executed in a speculative and out-of-order manner to fully utilize the resources of the processor.
摘要:
An integrated circuit having a normal mode for operating under normal operating conditions and a debug mode for operating to test and debug the integrated circuit. The integrated circuit includes a plurality of output pins that carry a first plurality of signals in the normal mode and carry a second plurality of signals in the debug mode. In one embodiment, the integrated circuit embodies a microprocessor. The microprocessor may include logic circuitry for enabling the second plurality of signals to be output from a multiplexer to the output pins in response to a predetermined event, such as a hit in an associated memory unit.
摘要:
A pipeline control system for implementing a virtual architecture having complex instruction set is distributed over RISC-like semi-autonomous functional units in a processor. Decoder logic fetches instructions of the target architecture and translates them into simpler RISC-like operations. These operations, each having an associated tag, are issued to the functional units. Address processing unit computes addresses of the instructions and operands, performs segment relocation, and manages the processor's memory. Operations are executed by the units in a manner that is generally independent of operation processing by the other units. The units report termination information back to the decoder logic, but do not irrevocably change the state of the machine. Based on the termination information, the decoder logic retires normally terminated operations in order. Thus, the functional units enable multiple operations to be executed in a speculative and out-of-order manner to fully utilize the resources of the processor.
摘要:
A pipeline control system is distributed over the functional units (15, 17, 20, 25) in a processor (10). Decoder logic (12) issues operations, each with an associated tag, to the functional units, with up to n operations allowed to be outstanding. The units execute the operations and report termination information back to the decoder logic, but do not irrevocably change the state of the machine. Based on the termination information, the decoder logic retires normally terminated operations in order. If an operation terminates abnormally, the decoder logic instructs the units to back out of those operations that include and are later than the operation that terminated abnormally.
摘要:
A pipeline control system for implementing a virtual architecture having a complex instruction set is distributed over RISC-like semi-autonomous functional units in a processor. Decoder logic fetches instructions of the target architecture and translates them into simpler RISC-like operations. These operations, each having an associated tag, are issued to the functional units. Address processing unit computes addresses of the instructions and operands, performs segment relocation, and manages the processor's memory. Operations are executed by the units in a manner that is generally independent of operation processing by the other units. The units report termination information back to the decoder logic, but do not irrevocably change the state of the machine. Based on the termination information, the decoder logic retires normally terminated operations in order. Thus, the functional units enable multiple operations to be executed in a speculative and out-of-order manner to fully utilize the resources of the processor.
摘要:
A pipeline control system is distributed over the functional units (15, 17, 20, 25) in a processor (10). Decoder logic (12) issues operations, each with an associated tag, to the functional units, with up to n operations allowed to be outstanding. The units execute the operations and report termination information back to the decoder logic, but do not irrevocably change the state of the machine. Based on the termination information, the decoder logic retires normally terminated operations in order. If an operation terminates abnormally, the decoder logic instructs the units to back out of those operations that include and are later than the operation that terminated abnormally.
摘要:
A pipeline control system is distributed over the functional units (15, 17, 20, 25) in a processor (10). Decoder logic (12) issues operations, each with an associated tag, to the functional units, with up to n operations allowed to be outstanding. The units execute the operations and report termination information back to the decoder logic, but do not irrevocably change the state of the machine. Based on the termination information, the decoder logic retires normally terminated operations in order. If an operation terminates abnormally, the decoder logic instructs the units to back out of those operations that include and are later than the operation that terminated abnormally.
摘要:
A pipeline control system is distributed over the functional units (15, 17, 20, 25) in a processor (10). Decoder logic (12) issues operations, each with an associated tag, to the functional units, with up to n operations allowed to be outstanding. The units execute the operations and report termination information back to the decoder logic, but do not irrevocably change the state of the machine. Based on the termination information, the decoder logic retires normally terminated operations in order. If an operation terminates abnormally, the decoder logic instructs the units to back out of those operations that include and are later than the operation that terminated abnormally.
摘要:
A data processing system includes an interconnect fabric, a system memory coupled to the interconnect fabric and including a virtual barrier synchronization region allocated to storage of virtual barrier synchronization registers (VBSRs), and a plurality of processing units coupled to the interconnect fabric and operable to access the virtual barrier synchronization region of the system memory. Each of the plurality of processing units includes a processor core and a cache memory including a cache array that caches VBSR lines from the virtual barrier synchronization region of the system memory and a cache controller. The cache controller, responsive to a store request from the processor core to update a particular VBSR line, performs a non-blocking update of the cache array in each other of the plurality of processing units contemporaneously holding a copy of the particular VBSR line by transmitting a VBSR update command on the interconnect fabric.
摘要:
In response to a data request, a victim cache line is selected for castout from a lower level cache, and a target lower level cache of one of the plurality of processing units is selected. A determination is made whether the selected target lower level cache has provided more than a threshold number of retry responses to lateral castout (LCO) commands of the first lower level cache, and if so, a different target lower level cache is selected. The first processing unit thereafter issues a LCO command on the interconnect fabric. The LCO command identifies the victim cache line to be castout and indicates that the target lower level cache is an intended destination of the victim cache line. In response to a successful coherence response to the LCO command, the victim cache line is removed from the first lower level cache and held in the second lower level cache.