Abstract: A processor includes a first prefetcher that prefetches data in response to memory accesses and a second prefetcher that prefetches data in response to memory accesses. Each of the memory accesses has an associated memory access type (MAT) of a plurality of predetermined MATs. The processor also includes a table that holds first scores that indicate effectiveness of the first prefetcher to prefetch data with respect to the plurality of predetermined MATs and second scores that indicate effectiveness of the second prefetcher to prefetch data with respect to the plurality of predetermined MATs. The first and second prefetchers selectively defer to one another with respect to data prefetches based on their relative scores in the table and the associated MATs of the memory accesses.

Abstract: A set associative cache memory, comprising: an array of storage elements arranged as M sets by N ways; an allocation unit that allocates the storage elements in response to memory accesses that miss in the cache memory. Each memory access selects a set; for each parcel of a plurality of parcels, a parcel specifier specifies: a subset of ways of the N ways included in the parcel. The subsets of ways of parcels associated with a selected set are mutually exclusive; a replacement scheme associated with the parcel from among a plurality of predetermined replacement schemes. For each memory access, the allocation unit: selects the parcel specifier in response to the memory access; and uses the replacement scheme associated with the parcel to allocate into the subset of ways of the selected set included in the parcel.

Abstract: A a set associative cache memory, comprising: an array of storage elements arranged as N ways; an allocation unit that allocates the storage elements of the array in response to memory accesses that miss in the cache memory; wherein each of the memory accesses has an associated memory access type (MAT) of a plurality of predetermined MATs, wherein the MAT is received by the cache memory; a mapping that, for each MAT of the plurality of predetermined MATs, associates the MAT with a subset of one or more ways of the N ways; wherein for each memory access of the memory accesses, the allocation unit allocates into a way of the subset of one or more ways that the mapping associates with the MAT of the memory access; and wherein the mapping is dynamically updatable during operation of the cache memory.

Abstract: A processor including a memory controller for interfacing an external memory and a programmable functional unit (PFU). The PFU is programmed by a PFU program to modify operation of the memory controller, in which the PFU includes programmable logic elements and programmable interconnectors. For example, the PFU is programmed by the PFU program to add a function or otherwise to modify an existing function of the memory controller enhance its functionality during operation of the processor. In this manner, the functionality and/or operation of the memory controller is not fixed once the processor is manufactured, but instead the memory controller may be modified after manufacture to improve efficiency and/or enhance performance of the processor, such as when executing a corresponding process.

Abstract: A cache memory stores 2^J-byte cache lines and includes an array of 2^N sets each holding tags each X bits, an input receives a Q-bit memory address, MA[(Q?1):0], having: a tag MA[(Q?1):(Q?X)] and an index MA[(Q?X?1):J]. Q is an integer at least (N+J+X?1). In a first mode: set selection logic selects one set using the index and LSB of the tag; comparison logic compares all but LSB of the tag with all but LSB of each tag in the selected set and indicates a hit if a match; otherwise allocation logic allocates into the selected set. In a second mode: the set selection logic selects two sets using the index; the comparison logic compares the tag with each tag in the selected two sets and indicates a hit if a match; and otherwise allocates into one set of the two selected sets.

Abstract: A controller for controlling a dynamic random access memory (DRAM) comprising a plurality of blocks. A block is one or more units of storage in the DRAM for which the DRAM controller can selectively enable or disable refreshing. The DRAM controller includes flags each for association with a block of the blocks of the DRAM. A sanitize controller determines a block is to be sanitized and in response sets a flag associated with the block and disables refreshing the block. In response to subsequently receiving a request to read data from a location in the block, if the flag is clear, the DRAM controller reads the location and returns data read from it. If the flag is set, the DRAM controller refrains from reading the DRAM and returns a value of zero.

Abstract: A set associative cache memory comprises an M×N memory array of storage entries arranged as M sets by N ways, both M and N are integers greater than one. Within each group of P mutually exclusive groups of the M sets, the N ways are separately powerable. A controller, for each group of the P groups, monitors a utilization trend of the group and dynamically causes power to be provided to a different number of ways of the N ways of the group during different time instances based on the utilization trend.

Abstract: A microprocessor comprises a cache including a tag array; a tag pipeline that arbitrates access to the tag array; and a pattern detector. The pattern detector comprises snapshot capture logic that captures snapshots of tagpipe arbs—including information about whether the tagpipe arb is a load, snoop, store or other arb type and whether the tagpipe arb completed or replayed—and a plurality of configurable register modules operable to store user-configured snapshot patterns. Configuration logic enables a user to specify, for each configurable register module, properties of tagpipe arbs for the pattern detector to detect as well as dependencies between the configurable register modules. A register module becomes triggered if a tagpipe arb or pattern of tagpipe arbs meets the user-specified properties for the register module and if any other register module on which the register module depends is also in a triggered state.

Abstract: A processor including a front end, at least one load pipeline, and a memory system that further includes a programmable prefetcher for prefetching information from an external memory. The front end converts fetched program instructions into microinstructions including load microinstructions and dispatches microinstructions for execution. The load pipeline executes dispatched load microinstructions and provides load requests to the memory system. The programmable prefetcher includes a load monitor, a programmable prefetch engine, and a prefetch requester. The load monitor tracks the load requests. The prefetch engine is configured to be programmed by at least one prefetch program to operate as a programmed prefetcher, such that during operation of the processor, the programmed prefetcher generates at least one prefetch address based on the load requests issued by the processor. The prefetch requester submits the at least one prefetch address to prefetch information from the memory system.

Abstract: A processor with an expandable instruction set architecture for dynamically configuring execution resources. The processor includes a programmable execution unit (PEU) that may be programmed to perform a user-defined function in response to a user-defined instruction (UDI). The PEU includes programmable logic elements and programmable interconnectors that are collectively programmed to perform at least one processing operation. A UDI loader is responsive to a UDI load instruction that specifies a UDI and a location of programming information that is used to program the PEU. The PEU may be programmed for one or more UDIs for one or more processes. An instruction table stores each UDI and corresponding information to identify the UDI and possibly to reprogram the PEU if necessary. A UDI handler consults the instruction table to identify a received UDI and to send corresponding information to the PEU to execute the corresponding user-defined function.

Abstract: A compiler system that converts an application source program into an executable program according to a predetermined ISA executable by a general purpose processor. The processor includes a PEU that is programmable to execute a UDI. The compiler system includes a PEU programming tool that converts a functional description of a processing operation to be performed by the PEU of the processor into programming information for programming the PEU to perform the processing operation in response to the specified UDI. The compiler system includes a compiler that converts the application source program into the executable program, which includes an optimization routine that represents a portion of the application source program with the specified UDI and that inserts the UDI into the executable program, and that further inserts into the executable program a UDI load instruction that specifies the UDI and a location of the programming information in the executable program.

Abstract: A conversion system that converts a standard executable program according to a predetermined ISA into a custom executable program executable by a general purpose processor. The processor includes a PEU that is programmable to execute a UDI. The conversion system includes a PEU programming tool that converts a functional description of a processing operation to be performed by the PEU of the processor into programming information for the PEU to perform the processing operation in response to the UDI. A converter converts the standard executable program into the custom executable program and includes an optimization routine that replaces a portion of the standard executable program with the specified UDI and that inserts the UDI into the custom executable program, and that further inserts a UDI load instruction that specifies the UDI and a location of the programming information in the custom executable program.

Abstract: A processor including a programmable prefetcher for prefetching information from an external memory. The programmable prefetcher includes a load monitor, a programmable prefetch engine, and a prefetch requester. The load monitor tracks load requests issued by the processor to retrieve information from the external memory. The programmable prefetch engine is configured to be programmed by at least one prefetch program to operate as a programmed prefetcher, such that during operation of the processor, the programmed prefetcher generates at least one prefetch address based on the load requests issued by the processor. The requester uses each generated prefetch address to prefetch information from the external memory. A prefetch memory may store one or more prefetch programs and a prefetch programmer may be included to select from among stored prefetch programs to program the prefetcher based on an executing process. Each prefetch program may be configured according to a prefetch definition.

Abstract: An associative cache memory, comprising: an array of storage elements arranged as M sets by N ways; an allocation unit allocates the storage elements in response to memory accesses that miss in the cache memory. Each memory access selects a set. Each memory access has an associated memory access type (MAT) of a plurality of predetermined MATs. Each valid storage element has an associated MAT; a mapping that includes, for each MAT, a MAT priority. In response to a memory access that misses in the array, the allocation unit: determines a most eligible way and a second most eligible way of the selected set for replacement based on a replacement policy; and replaces the second most eligible way rather than the most eligible way when the MAT priority of the most eligible way is greater than the MAT priority of the second most eligible way.

Abstract: A fully associative cache memory, comprising: an array of storage elements; an allocation unit that allocates the storage elements in response to memory accesses that miss in the cache memory. Each memory access has an associated memory access type (MAT) of a plurality of predetermined MATs. Each valid storage element of the array has an associated MAT. For each MAT, the allocation unit maintains: a counter that counts of a number of valid storage elements associated with the MAT; and a corresponding threshold. The allocation unit allocates into any of the storage elements in response to a memory access that misses in the cache, unless the counter of the MAT of the memory access has reached the corresponding threshold, in which case the allocation unit replaces one of the valid storage elements associated with the MAT of the memory access.

Abstract: A processor includes a prefetcher that prefetches data in response to memory accesses, wherein each memory access has an associated memory access type (MAT) of a plurality of predetermined MATs. The processor also includes a table that holds scores that indicate effectiveness of the prefetcher to prefetch data with respect to the plurality of predetermined MATs. The prefetcher prefetches data in response to memory accesses at a level of aggressiveness based on the scores held in the table and the associated MATs of the memory accesses.

Abstract: A microprocessor includes a main processor and a service processor. The service processor is configured to detect and break a deadlock/livelock condition in the main processor. The service processor detects the deadlock/livelock condition by detecting the main processor has not retired an instruction or completed a processor bus transaction for a predetermined number of clock cycles. In response to detecting the deadlock/livelock condition in the main processor, the service processor causes arbitration requests to a cache memory to be captured in a buffer, analyzes the captured requests to detect a pattern that may indicate a bug causing the condition and performs actions associated with the pattern to break the deadlock/livelock. The actions include suppression of arbitration requests to the cache, suppression of comparisons cache request addresses and killing requests to access the cache.

Abstract: A cache memory stores 2?J-byte cache lines and includes an array of 2?N sets each holding tags each X bits, an input receives a Q-bit memory address, MA[(Q?1):0], having: a tag MA[(Q?1):(Q?X)] and an index MA[(Q?X?1):J]. Q is an integer at least (N+J+X?1). In a first mode: set selection logic selects one set using the index and LSB of the tag; comparison logic compares all but LSB of the tag with all but LSB of each tag in the selected set and indicates a hit if a match; otherwise allocation logic allocates into the selected set. In a second mode: the set selection logic selects two sets using the index; the comparison logic compares the tag with each tag in the selected two sets and indicates a hit if a match; and otherwise allocates into one set of the two selected sets.

Abstract: A processor includes a first prefetcher that prefetches data in response to memory accesses and a second prefetcher that prefetches data in response to memory accesses. Each of the memory accesses has an associated memory access type (MAT) of a plurality of predetermined MATs. The processor also includes a table that holds first scores that indicate effectiveness of the first prefetcher to prefetch data with respect to the plurality of predetermined MATs and second scores that indicate effectiveness of the second prefetcher to prefetch data with respect to the plurality of predetermined MATs. The first and second prefetchers selectively defer to one another with respect to data prefetches based on their relative scores in the table and the associated MATs of the memory accesses.

Abstract: A set associative cache memory, comprising: an array of storage elements arranged as M sets by N ways; an allocation unit that allocates the storage elements in response to memory accesses that miss in the cache memory. Each memory access selects a set; for each parcel of a plurality of parcels, a parcel specifier specifies: a subset of ways of the N ways included in the parcel. The subsets of ways of parcels associated with a selected set are mutually exclusive; a replacement scheme associated with the parcel from among a plurality of predetermined replacement schemes. For each memory access, the allocation unit: selects the parcel specifier in response to the memory access; and uses the replacement scheme associated with the parcel to allocate into the subset of ways of the selected set included in the parcel.