Abstract: A streaming engine employed in a digital signal processor specified a fixed data stream. Once started the data stream is read only and cannot be written. Once fetched the data stream is stored in a first-in-first-out buffer for presentation to functional units in the fixed order. Data use by the functional unit is controlled using the input operand fields of the corresponding instruction. A read only operand coding supplies the data an input of the functional unit. A read/advance operand coding supplies the data and also advances the stream to the next sequential data elements. The read only operand coding permits reuse of data without requiring a register of the register file for temporary storage.

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 streaming engine employed in a digital data processor specifies a fixed read only data stream defined by plural nested loops. An address generator produces addresses of data elements. A steam head register stores data elements next to be supplied to functional units for use as operands. Stream metadata is stored in response to a stream store instruction. Stored stream metadata is restored to the stream engine in response to a stream restore instruction. An interrupt changes an open stream to a frozen state discarding stored stream data. A return from interrupt changes a frozen stream to an active state.

Abstract: A streaming engine employed in a digital data processor specifies fixed first and second read only data streams. Corresponding stream address generator produces address of data elements of the two streams. Corresponding steam head registers stores data elements next to be supplied to functional units for use as operands. The two streams share two memory ports. A toggling preference of stream to port ensures fair allocation. The arbiters permit one stream to borrow the other's interface when the other interface is idle. Thus one stream may issue two memory requests, one from each memory port, if the other stream is idle. This spreads the bandwidth demand for each stream across both interfaces, ensuring neither interface becomes a bottleneck.

Abstract: This invention is a streaming engine employed in a digital signal processor. A fixed data stream sequence including plural nested loops is specified by a control register. The streaming engine includes an address generator producing addresses of data elements and a steam head register storing data elements next to be supplied as operands. The streaming engine fetches stream data ahead of use by the central processing unit core in a stream buffer. Parity bits are formed upon storage of data in the stream buffer which are stored with the corresponding data. Upon transfer to the stream head register a second parity is calculated and compared with the stored parity. The streaming engine signals a parity fault if the parities do not match. The streaming engine preferably restarts fetching the data stream at the data element generating a parity fault.

Abstract: This invention addresses implements a range of interesting technologies into a single block. Each DSP CPU has a streaming engine. The streaming engines include: a SE to L2 interface that can request 512 bits/cycle from L2; a loose binding between SE and L2 interface, to allow a single stream to peak at 1024 bits/cycle; one-way coherence where the SE sees all earlier writes cached in system, but not writes that occur after stream opens; full protection against single-bit data errors within its internal storage via single-bit parity with semi-automatic restart on parity error.

Abstract: This invention is a streaming engine employed in a digital signal processor. A fixed data stream sequence is specified by a control register. The streaming engine fetches stream data ahead of use by a central processing unit and stores it in a stream buffer. Upon occurrence of a fault reading data from memory, the streaming engine identifies the data element triggering the fault preferably storing this address in a fault address register. The streaming engine defers signaling the fault to the central processing unit until this data element is used as an operand. If the data element is never used by the central processing unit, the streaming engine never signals the fault. The streaming engine preferably stores data identifying the fault in a fault source register. The fault address register and the fault source register are preferably extended control registers accessible only via a debugger.

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 fetches stream data ahead of use by the central processing unit core in a stream buffer constructed like a cache. The stream buffer cache includes plural cache lines, each includes tag bits, at least one valid bit and data bits. Cache lines are allocated to store newly fetched stream data. Cache lines are deallocated upon consumption of the data by a central processing unit core functional unit. Instructions preferably include operand fields with a first subset of codings corresponding to registers, a stream read only operand coding and a stream read and advance operand coding.

Abstract: A streaming engine employed in a digital data processor specifies a fixed read only data stream. An address generator produces virtual addresses of data elements. An address translation unit converts these virtual addresses to physical addresses by comparing the most significant bits of a next address N with the virtual address bits of each entry in an address translation table. Upon a match, the translated address is the physical address bits of the matching entry and the least significant bits of address N. The address translation unit can generate two translated addresses. If the most significant bits of address N+1 match those of address N, the same physical address bits are used for translation of address N+1. The sequential nature of the data stream increases the probability that consecutive addresses match the same address translation entry and can use this technique.

Abstract: This invention addresses implements a range of interesting technologies into a single block. Each DSP CPU has a streaming engine. The streaming engines include: a SE to L2 interface that can request 512 bits/cycle from L2; a loose binding between SE and L2 interface, to allow a single stream to peak at 1024 bits/cycle; one-way coherence where the SE sees all earlier writes cached in system, but not writes that occur after stream opens; full protection against single-bit data errors within its internal storage via single-bit parity with semi-automatic restart on parity error.

Abstract: This invention is data processing apparatus and method. Data is protecting from corruption using an error correction code by generating an error correction code corresponding to the data. In this invention the data and the corresponding error correction code are carried forward to another set of registers without regenerating the error correction code or using the error correction code for error detection or correction. Only later are error correction detection and correction actions taken. The differing data/error correction code registers may be in differing pipeline phases in the data processing apparatus. This invention forwards the error correction code with the data through the entire datapath that carries the data. This invention provides error protection to the whole datapath without requiring extensive hardware or additional time.

Abstract: This invention is data processing apparatus and method. Data is protecting from corruption using an error correction code by generating an error correction code corresponding to the data. In this invention the data and the corresponding error correction code are carried forward to another set of registers without regenerating the error correction code or using the error correction code for error detection or correction. Only later are error correction detection and correction actions taken. The differing data/error correction code registers may be in differing pipeline phases in the data processing apparatus. This invention forwards the error correction code with the data through the entire datapath that carries the data. This invention provides error protection to the whole datapath without requiring extensive hardware or additional time.

Abstract: The Multicore Bus Architecture (MBA) protocol includes a novel technique of sharing the same physical channel for all transaction types. Two channels, the Transaction Attribute Channel (TAC) and the Transaction Data Channel (TDC) are used. The attribute channel transmits bus transaction attribute information optionally including a transaction type signal, a transaction ID, a valid signal, a bus agent ID signal, an address signal, a transaction size signal, a credit spend signal and a credit return signal. The data channel connected a data subset of the signal lines of the bus separate from the attribute subset of signal lines the bus. The data channel optionally transmits a data valid signal, a transaction ID signal, a bus agent ID signal and a last data signal to mark the last data of a current bus transaction.

Abstract: This invention is a bus communication protocol. A master device stores bus credits. The master device may transmit a bus transaction only if it holds sufficient number and type of bus credits. Upon transmission, the master device decrements the number of stored bus credits. The bus credits correspond to resources on a slave device for receiving bus transactions. The slave device must receive the bus transaction if accompanied by the proper credits. The slave device services the transaction. The slave device then transmits a credit return. The master device adds the corresponding number and types of credits to the stored amount. The slave device is ready to accept another bus transaction and the master device is re-enabled to initiate the bus transaction. In many types of interactions a bus agent may act as both master and slave depending upon the state of the process.

Abstract: A statically scheduled processor compiler schedules a speculative load in the program before the data is needed. The compiler inserts a conditional instruction confirming or disaffirming the speculative load before the program behavior changes due to the speculative load. The condition is not based solely upon whether the speculative load address is correct but preferably includes dependence according to the original source code. The compiler may statically schedule two or more branches in parallel with orthogonal conditions.

Abstract: A statically scheduled processor compiler schedules a speculative load in the program before the data is needed. The compiler inserts a conditional instruction confirming or disaffirming the speculative load before the program behavior changes due to the speculative load. The condition is not based solely upon whether the speculative load address is correct but preferably includes dependence according to the original source code. The compiler may statically schedule two or more branches in parallel with orthogonal conditions.

Abstract: This invention addresses implements a range of interesting technologies into a single block. Each DSP CPU has a streaming engine. The streaming engines include: a SE to L2 interface that can request 512 bits/cycle from L2; a loose binding between SE and L2 interface, to allow a single stream to peak at 1024 bits/cycle; one-way coherence where the SE sees all earlier writes cached in system, but not writes that occur after stream opens; full protection against single-bit data errors within its internal storage via single-bit parity with semi-automatic restart on parity error.

Abstract: A predication method for vector processors that minimizes the use of embedded predicate fields in most instructions by using separate condition code extensions. Dedicated predicate registers provide fine grain predication of vector instructions where each bit of a predicate register controls 8 bit of the vector data.

Abstract: The number of registers required is reduced by overlapping scalar and vector registers. This also allows increased compiler flexibility when mixing scalar and vector instructions. Local register read ports are minimized by restricting read access. Dedicated predicate registers reduces requirements for general registers, and allows reduction of critical timing paths by allowing the predicate registers to be placed next to the predicate unit.

Abstract: In order to eliminate almost all the hardware cost associated with branch prediction, a new scheme for a statically scheduled VLIW Processor speculatively reads the condition for a branch one or more cycles earlier than when it can be guaranteed to be correct. This is facilitated by the fact that the branch condition is a predicate derived from the value of a general-purpose register, and stored in a separate location.