摘要:
An embedded megamodule and an embedded CPU enable power-saving through a combination of hardware and software. The CPU configures the power-down controller (PDC) logic within megamodule and can software trigger a low-power state of logic modules during processor IDLE periods. To wake from this power-down state, a system event is asserted to the CPU through the module interrupt controller. Thus the entry into a low-power state is software-driven during periods of inactivity and power restoration is on system activity that demands the attention of the CPU.
摘要:
An embedded megamodule and an embedded CPU enable power-saving through a combination of hardware and software. The CPU configures the power-down controller (PDC) logic within megamodule and can software trigger a low-power state of logic modules during processor IDLE periods. To wake from this power-down state, a system event is asserted to the CPU through the module interrupt controller. Thus the entry into a low-power state is software-driven during periods of inactivity and power restoration is on system activity that demands the attention of the CPU.
摘要:
A memory system or a digital signal processor (DSP) includes single-bit-error detection hardware in its level two (L2) memory controller to mitigate the effects of soft errors. Error detection hardware detects erroneous data that is fetched by the central processing unit and signals the central processing unit. The parity is generated and checked only for whole memory line accesses. This technique is especially useful for cache memory. The central processing unit can query the memory controller as to the specific location that generated the error and decide the next course of action based on the type of data affected.
摘要:
Parallel pipelines are used to access a shared memory. The shared memory is accessed via a first pipeline by a processor to access cached data from the shared memory. The shared memory is accessed via a second pipeline by a memory access unit to access the shared memory. A first set of tags is maintained for use by the first pipeline to control access to the cache memory, while a second set of tags is maintained for use by the second pipeline to access the shared memory. Arbitrating for access to the cache memory for a transaction request in the first pipeline and for a transaction request in the second pipeline is performed after each pipeline has checked its respective set of tags.
摘要:
Parallel pipelines are used to access a shared memory. The shared memory is accessed via a first pipeline by a processor to access cached data from the shared memory. The shared memory is accessed via a second pipeline by a memory access unit to access the shared memory. A first set of tags is maintained for use by the first pipeline to control access to the cache memory, while a second set of tags is maintained for use by the second pipeline to access the shared memory. Arbitrating for access to the cache memory for a transaction request in the first pipeline and for a transaction request in the second pipeline is performed after each pipeline has checked its respective set of tags.
摘要:
This invention is an exception priority arbitration unit which prioritizes memory access permission fault and data exception signals according to a fixed hierarchy if received during a same cycle. A CPU memory access permission fault is prioritized above a DMA memory access permission fault of a direct memory access permission fault. Any memory access permission fault is prioritized above a data exception signal. A non-correctable data exception signal is prioritized above a correctable data exception signal.
摘要:
A clock divider divides a high speed input clock signal by an odd, even or fractional divide ratio. The clock divider receives a divide factor value F representative of a divide ratio N, wherein the N may be an odd or an even integer. A fractional indicator indicates a fractional divide ratio when one and an integral divide ratio when zero. A count indicator is asserted every N/2 input clock cycles when N is even. The count indicator is asserted alternately N/2 input clock cycles and then 1+N/2 input clock cycles when N is odd. The clock divider synthesizes one period of an output clock signal in response to each assertion of the count indicator for a fractional divide ratio and synthesizes one period of the output clock signal in response to two assertions of the count indicator for an integral divide ratio.
摘要:
This invention permits user controlled cache coherence operations with the flexibility to do these operations on all levels of cache together or each level independently. In the case of an all level operation, the user does not have to monitor and sequence each phase of the operation. This invention also provides a way for users to track completion of these operations. This is critical for multi-core/multi-processor devices. Multiple cores may be accessing the end point and the user/application needs to be able to identify when the operation from one core is complete, before permitting other cores access that data or code.
摘要:
A shared memory system having multiple banks is coupled to a set of requesters. Separate arbitration and control logic is provided for each bank, such that each bank can be accessed individually. The separate arbitration logics individually arbitrate transaction requests targeted to each bank of the memory. Access is granted to each bank on each access cycle to a highest priority request for each bank, such that more than one transaction request may be granted access to the memory on a same access cycle. A wide transaction request that has a transaction width that is wider than a width of one bank is divided into a plurality of divided requests.
摘要:
A system on a single integrated circuit chip (SoC) includes a plurality of operational circuits to be tested. A plurality of programmable built-in self-test (pBIST) controllers is connected to respective ones of the plurality of operational circuits in a manner that allows the pBIST controllers to test the respective operation circuits in parallel. An interface is connected to each of the plurality of pBIST controllers for connection to an external tester to facilitate programming of each of the plurality of pBIST controllers by the external tester, such that the plurality of pBIST controllers are operable to test the plurality of operational circuits in parallel and report the results of the parallel tests to the external tester, thereby reducing test time.