Abstract: A streaming engine employed in a digital data processor specifies a fixed read only data stream defined by plural nested loops. An address generator produces address of data elements. A steam head register stores data elements next to be supplied to functional units for use as operands. An element duplication unit optionally duplicates data element an instruction specified number of times. A vector masking unit limits data elements received from the element duplication unit to least significant bits within an instruction specified vector length. If the vector length is less than a stream head register size, the vector masking unit stores all 0?s in excess lanes of the stream head register (group duplication disabled) or stores duplicate copies of the least significant bits in excess lanes of the stream head register.

Abstract: A streaming engine employed in a digital data processor specifies a fixed read only data stream defined by plural nested loops. An address generator produces address of data elements. A steam head register stores data elements next to be supplied to operational units for use as operands. A promotion unit optionally increases date element data size by an integral power of 2 either zero filing or sign filling the additional bits. A decimation unit optionally decimates data elements by an integral factor of 2. For ease of implementation the promotion factor must be greater than or equal to the decimation factor.

Abstract: A digital signal processor having a CPU with a program counter register and, optionally, an event context stack pointer register for saving and restoring the event handler context when higher priority event preempts a lower priority event handler. The CPU is configured to use a minimized set of addressing modes that includes using the event context stack pointer register and program counter register to compute an address for storing data in memory. The CPU may also eliminate post-decrement, pre-increment and post-decrement addressing and rely only on post-increment addressing.

Abstract: A streaming engine employed in a digital data processor specifies a fixed read only data stream. Once fetched data elements in the data stream are disposed in lanes in a stream head register in the fixed order. Some lanes may be invalid, for example when the number of remaining data elements are less than the number of lanes in the stream head register. The streaming engine automatically produces a valid data word stored in a stream valid register indicating lanes holding valid data. The data in the stream valid register may be automatically stored in a predicate register or otherwise made available. This data can be used to control vector SIMD operations or may be combined with other predicate register data.

Abstract: A streaming engine employed in a digital signal processor specifies a fixed read only data stream. Once fetched the data stream is stored in two head registers for presentation to functional units in the fixed order. Data use by the functional unit is preferably controlled using the input operand fields of the corresponding instruction. A first read only operand coding supplies data from the first head register. A first read/advance operand coding supplies data from the first head register and also advances the stream to the next sequential data elements. Corresponding second read only operand coding and second read/advance operand coding operate similarly with the second head register. A third read only operand coding supplies double width data from both head registers.

Abstract: A multilayer butterfly network is shown that is operable to transform and align a plurality of fields from an input to an output data stream. Many transformations are possible with such a network which may include separate control of each multiplexer. This invention supports a limited set of multiplexer control signals, which enables a similarly limited set of data transformations. This limited capability is offset by the reduced complexity of the multiplexor control circuits. This invention used precalculated inputs and simple combinatorial logic to generate control signals for the butterfly network. Controls are independent for each layer and therefore are dependent only on the input and output patterns. Controls for the layers can be calculated in parallel.

Abstract: A streaming engine employed in a digital data processor specifies a fixed read only data stream defined by plural nested loops. An address generator produces address of data elements for the nested loops. A steam head register stores data elements next to be supplied to functional units for use as operands. A stream template specifies loop count and loop dimension for each nested loop. A format definition field in the stream template specifies the number of loops and the stream template bits devoted to the loop counts and loop dimensions. This permits the same bits of the stream template to be interpreted differently enabling trade off between the number of loops supported and the size of the loop counts and loop dimensions.

Abstract: A system, method, and device are shown that are operable to transform and align a plurality of fields from an input to an output data stream using a multilayer butterfly or inverse butterfly network by selectably switching bit positions of the input data stream. In some examples, a device includes a first circuit configured to selectably switch bit positions of a first subset of the data stream with a second subset of the data stream and a second circuit configured to: selectably switch bit positions of a first subset of the first subset of the data stream with a second subset of the first subset of the data stream, and selectably switch bit positions of a first subset of the second subset of the data stream with a second subset of the second subset of the data stream.

Abstract: A streaming engine employed in a digital data processor specifies a fixed read only data stream defined by plural nested loops. An address generator produces address of data elements for the nested loops. A steam head register stores data elements next to be supplied to functional units for use as operands. A stream template register specifies a circular address mode for the loop, first and second block size numbers and a circular address block size selection. For a first circular address block size selection the block size corresponds to the first block size number. For a first circular address block size selection the block size corresponds to the first block size number. For a second circular address block size selection the block size corresponds to a sum of the first block size number and the second block size number.

Abstract: Techniques related to executing a plurality of instructions by a processor comprising a method for executing a plurality of instructions by a processor. The method comprises detecting a pipeline hazard based on one or more instructions provided for execution by an instruction execution pipeline, beginning execution of an instruction, of the one or more instructions on the instruction execution pipeline, stalling a portion of the instruction execution pipeline based on the detected pipeline hazard, storing a register state associated with the execution of the instruction based on the stalling, determining that the pipeline hazard has been resolved, and restoring the register state to the instruction execution pipeline based on the determination.

Abstract: A processor includes a functional unit, and a set of vector registers coupled to the functional unit. The processor executes an instruction to cause the functional unit to classify each value of multiple floating-point values stored in a first vector register of the set of vector registers, and store in a second vector register of the set of registers multiple elements that each indicate a respective classification of a respective value of the multiple floating-point values. The first and second vector registers may be source and destination vector registers, and each may be specified by the instruction. The classify and store operations may also be specified by the instruction. The instruction may be embodied on a device-readable medium.

Abstract: An integrated circuit, comprising an instruction pipeline that includes instruction fetch phase circuitry, instruction decode phase circuitry, and instruction execution circuitry. The instruction execution circuitry includes transformation circuitry for receiving an interleaved dual vector operand as an input and for outputting a first natural order vector including a first set of data values from the interleaved dual vector operand and a second natural order vector including a second set of data values from the interleaved dual vector operand.

Abstract: A streaming engine employed in a digital data processor specifies a fixed read only data stream defined by plural nested loops. An address generator produces address of data elements. A steam head register stores data elements next to be supplied to functional units for use as operands. An element duplication unit optionally duplicates data element an instruction specified number of times. A vector masking unit limits data elements received from the element duplication unit to least significant bits within an instruction specified vector length. If the vector length is less than a stream head register size, the vector masking unit stores all 0's in excess lanes of the stream head register (group duplication disabled) or stores duplicate copies of the least significant bits in excess lanes of the stream head register.

Abstract: A streaming engine employed in a digital data processor specifies a fixed read only data stream defined by plural nested loops. An address generator produces address of data elements. A steam head register stores data elements next to be supplied to operational units for use as operands. A promotion unit optionally increases date element data size by an integral power of 2 either zero filing or sign filling the additional bits. A decimation unit optionally decimates data elements by an integral factor of 2. For ease of implementation the promotion factor must be greater than or equal to the decimation factor.

Abstract: A digital signal processor having a CPU with a program counter register and, optionally, an event context stack pointer register for saving and restoring the event handler context when higher priority event preempts a lower priority event handler. The CPU is configured to use a minimized set of addressing modes that includes using the event context stack pointer register and program counter register to compute an address for storing data in memory. The CPU may also eliminate post-decrement, pre-increment and post-decrement addressing and rely only on post-increment addressing.

Abstract: A streaming engine employed in a digital data processor specifies a fixed read only data stream defined by plural nested loops. An address generator produces address of data elements. A steam head register stores data elements next to be supplied to functional units for use as operands. Upon a stream break instruction specifying one of the nested loops, the stream engine ends a current iteration of the loop. If the specified loop was not the outermost loop, the streaming engine begins an iteration of a next outer loop. If the specified loop was the outermost nested loop, the streaming engine ends the stream. The streaming engine places a vector of data elements in order in lanes within a stream head register. A stream break instruction is operable upon a vector break.

Abstract: A streaming engine employed in a digital data processor specifies a fixed read only data stream defined by plural nested loops. An address generator produces address of data elements. A steam head register stores data elements next to be supplied to functional units for use as operands. The streaming engine stores an early address of next to be fetched data elements and a late address of a data element in the stream head register for each of the nested loops. The streaming engine stores an early loop counts of next to be fetched data elements and a late loop counts of a data element in the stream head register for each of the nested loops.

Abstract: A streaming engine employed in a digital data processor may specify a fixed read-only data stream defined by plural nested loops. An address generator produces address of data elements for the nested loops. A steam head register stores data elements next to be supplied to functional units for use as operands. A stream template register independently specifies a linear address or a circular address mode for each of the nested loops.

Abstract: A multilayer butterfly network is shown that is operable to transform and align a plurality of fields from an input to an output data stream. Many transformations are possible with such a network which may include separate control of each multiplexer. This invention supports a limited set of multiplexer control signals, which enables a similarly limited set of data transformations. This limited capability is offset by the reduced complexity of the multiplexor control circuits. This invention used precalculated inputs and simple combinatorial logic to generate control signals for the butterfly network. Controls are independent for each layer and therefore are dependent only on the input and output patterns. Controls for the layers can be calculated in parallel.

Abstract: Techniques related to executing a plurality of instructions by a processor comprising receiving a first instruction for execution on an instruction execution pipeline, beginning execution of the first instruction, receiving one or more second instructions for execution on the instruction execution pipeline, the one or more second instructions associated with a higher priority task than the first instruction, storing a register state associated with the execution of the first instruction in one or more registers of a capture queue associated with the instruction execution pipeline, copying the register state from the capture queue to a memory, determining that the one or more second instructions have been executed, copying the register state from the memory to the one or more registers of the capture queue, and restoring the register state to the instruction execution pipeline from the capture queue.