Abstract: Bus communication for components of a system on a chip. In one aspect of the invention, a serializer for interfacing bus communications for a master in a bus system includes one or more shift registers that serialize information to send over a communication bus and deserialize information received from the communication bus. A mechanism provides parallel bus information from the master to the shift registers for serialization, where the mechanism provides deserialized information received from the shift registers to the master, and where the mechanism inserts one or more wait cycles in communication with the master during the serialization and deserialization.

Abstract: Bus communication for components of a system on a chip. In one aspect of the invention, a serializer for interfacing bus communications for a slave in a bus system includes one or more shift registers that serialize information to send over a communication bus and deserialize information received from the communication bus. A mechanism provides parallel bus information from a bus matrix to the shift registers for serialization and communication to the slave, where the mechanism provides deserialized information received from the shift registers to a bus matrix. The mechanism inserts one or more wait cycles in communication with the matrix during the serialization and deserialization.

Abstract: Systems and methods for performing data transfer rate throttling o improve the effective data transfer rate for SATA storage devices. The data transfer rate is diluted by inserting ALIGN primitives when data is sent. The receiving device simply discards the ALIGN primitives. Therefore, the receive data FIFO does not fill as quickly and fewer flow control sequences are needed for flow control to prevent the receive data FIFO from overflowing. An advantage of using the ALIGN primitives instead of conventional flow control is that the round-trip handshake latency is not incurred to disable and later enable data transfers.

Abstract: A digital Storage Element is described. A device is configured including a Storage Element for access by a user responsive to a native control code. A processing arrangement executes a control program for controlling the overall device and executing at least a portion of the native control code as part of the control program for interfacing with the Storage Element. A programming arrangement is provided separate from the device for customizing a read channel within the Storage Element. Command, user interaction and data transfer execution are discussed for mitigation of potential mechanical shock effects. Status indications relating to the Storage Element are provided including head position and mechanical shock. Calibration, test and operational monitoring procedures, for using head position status, are described. Failure configuration monitoring is provided in tracking overall performance and design considerations.

Abstract: A Direct Memory Access (DMA) device includes a first buffer which holds a first transfer information required for a first transfer request, and a second buffer which holds a second transfer information required for a second transfer request, and a transfer request comparison circuit which determines whether or not a current transfer request, which is newly inputted, matches with the first transfer request or the second transfer request.

Abstract: The present invention provides a method and a system for providing cache management commands in a system supporting a DMA mechanism and caches. A DMA mechanism is set up by a processor. Software running on the processor generates cache management commands. The DMA mechanism carries out the commands, thereby enabling the software program management of the caches. The commands include commands for writing data to the cache, loading data from the cache, and for marking data in the cache as no longer needed. The cache can be a system cache or a DMA cache.

Abstract: An apparatus and a process for transferring packet data includes receiving packets from a first interface such as a network interface and transferring data to a second interface such as an SD Bus interface such as SDIO using a protocol such as one described in SDCard.org. The SD Bus second interface operates as a slave device to a master device, and the packet transfer from first interface to second interface includes concatenating length fields and packet data fields from packets received on the first interface to form a superframe which is provided to the second interface at time of data transfer. The formation of each superframe includes starting a timer such that the superframe is transmitted to the second interface by asserting an interrupt on that interface when either the timer expires, the number of packet from the first interface exceeds a threshold, or the amount of data from the first interface exceeds a threshold.

Abstract: Timing of a write and read strobes for a memory having a double data rate (DDR) interface are automatically adjusted using write-read operations. A first and a second value of the write and read strobes are determined for a first write-read operation having the read data match the write data. A second write-read operation is performed for each of a plurality of third values for the write strobe at the second value for the read strobe set. A center of the third values having the read data match the write data is determined. A third write-read operation is performed for each of a plurality of fifth values for the read strobe at the fourth value of the write strobe. A center of the fifth values having the read data match the write data is determined. The timing of the write and read strobes are set to the centers.

Abstract: Restoring retired transaction identifiers (TID) associated with Direct Memory Access (DMA) commands without waiting for all DMA traffic to terminate is disclosed. A scoreboard is used to track retired TIDs and selectively restore retired TIDs on the fly. DMA engines fetch a TID, and use it to tag every DMA request. If the request is completed, the TID can be recycled to be used to tag a subsequent request. However, if a request is not completed, the TID is retired. Retired TIDs can be restored without having to wait for DMA traffic to end. Any retired TID value may be mapped to a bit location inside a scoreboard. All processors in the system may have access to read and clear the scoreboard. Clearing the TID scoreboard may trigger a DMA engine to restore the TID mapped to that location, and the TID may be used again.

Abstract: The serial communication device capable of reducing the load on the CPU is provided for a system using the serial communications such as the car navigation system. The attention is focused on the control method of the serial communication, in which a DMA controller is used for the data reception in the serial communication, and a number larger than the number of data received at a time is set in advance as the number of transfers of the receive DMA controller, and further, the function to generate the timeout interrupt when data is not received for a certain period is added to the serial interface, so that the serial communication can be controlled and performed without applying the load on the CPU.

Abstract: A data access device for a communication system includes: a write controller controlled by the host and outputting a write pointer; a read controller controlled by the write pointer and outputting a read pointer; a download timing controller comparing the write and read pointers to determine a timing of downloading data from the host, and including a pointer difference calculator and a comparator, the pointer difference calculator calculating a distance between the write and read pointers to obtain a pointer difference, the comparator outputting a download status indication according to the pointer difference and a first predetermined length to provide a basis for changing the write pointer; and a transmit buffer downloading data from the host according to the write pointer and transmitting data to the network interface according to the read pointer. A data access device for a network interface controller and a data access method are also disclosed.

Abstract: A method transfers data between a memory and peripheral units. The method includes assigning priorities to the data to be transferred, and transferring the data by direct memory access (DMA) control between the memory and the peripheral units in conformity with the priorities assigned in each case.

Abstract: A computer system according to an example of the invention comprises SPEs and a global memory. The SPEs include a running SPE and an idling SPE. The running SPE and the idling SPE each have a processor core, local memory and DMA module. The local memory of the idling SPE stores data stored in the global memory and used by the processor core of the running SPE, before the data is used by the processor core of the running SPE. The DMA module of the running SPE reads the data from the local memory of the idling SPE, and transfers the data to the processor core of the running SPE.

Abstract: A method and system is disclosed for accessing I/O and memory devices utilizing a DMA controller. Each device may be connected to the DMA controller through an individual channel. Clocking circuitry in the DMA may allow the DMA controller to send signals to each device at a prescribed frequency. Furthermore, the DMA controller is capable of activating and deactivating a channel clock, used in sending signals to the devices, based on the operational status of the individual devices. The DMA controller is also capable of tuning the channel clock dependant on the capabilities of any active devices. In this manner, the amount of bandwidth used during a DMA data transfer can be tailored to the specific requirements of the devices involved with the data transfer.

Abstract: A method for arbitrating between direct memory access task requests, the method includes receiving multiple DMA task requests; the method is characterized by selecting a DMA task request out of the multiple DMA task requests in response to timing deadlines associated with the DMA tasks. A device that includes an interface, that is adapted to receive DMA task requests; the device is characterized by including an arbiter that is adapted to select a DMA task request out of the multiple DMA task requests in response to timing deadlines associated with the DMA tasks.

Abstract: A computerized system is described (i) which includes an interface connected with a peripheral device and (ii) which is incapable of dynamically extending bus cycle timing if required by the peripheral device to carry out a particular current operation. This computerized system includes a given peripheral device which, during normal operation of the device, can require an extension of bus cycle timing to carry out the current operation. This device generates a specific signal when the extension is required. The device is connected with the interface of the computerized system and the system is configured to cause the system (i) to recognize the specific signal and (ii) to instruct the peripheral device to retry the current operation responsive to the specific signal. In a particular embodiment, the peripheral device is a disk drive having an ATA interface and the specific signal generated by the disk drive is an IORDY signal.

Abstract: The image processing apparatus (data processing apparatus) stores data in a storing unit (storing means), inputs and outputs the data to and from the storing unit via a storage control unit (input-output means) and processes the data outputted from the storing unit with a control unit (processing means). The storage control unit inputs and outputs image data to and from the storing unit by the DMA method through a path via a DMA control unit and inputs and outputs other data such as a control instruction to and from the storing unit by the PIO method through a path via a PIO control unit. Image data to be inputted and outputted to and from the storing unit by the DMA method is encrypted in an input operation and decrypted in an output operation by an encryption/decryption unit provided on the input-output path for DMA method.

Abstract: A control machine which uses a data amount stored in an FIFO as a trigger and allows a DMA transfer to be started according to a capacity of the FIFO allows a control machine for preparing for the DMA transfer to start to prepare a command and the like for the DMA transfer. The control machine for preparing for the DMA transfer issues the prepared command to a control machine for transferring DMA data, so that a process according to the command is started. At the time of the DMA transfer, a burden on a host CPU is reduced.

Abstract: A method, system and program are provided for dynamically allocating DMA channel identifiers to multiple DMA transfer requests that are grouped in time by virtualizing DMA transfer requests into an available DMA channel identifier using a channel bitmap listing of available DMA channels to select and set an allocated DMA channel identifier. Once the input values associated with the DMA transfer requests are mapped to the selected DMA channel identifier, the DMA transfers are performed using the selected DMA channel identifier, which is then deallocated in the channel bitmap upon completion of the DMA transfers. When there is a request to wait for completion of the data transfers, the same input values are used with the mapping to wait on the appropriate logical channel. With this method, all available logical channels can be utilized with reduced instances of false-sharing.

Abstract: A data transfer control apparatus includes a channel controller and plural transfer controllers. The channel controller receives, prioritizes and queues data transfer requests. An event to transfer controller table enables recall of a transfer controller number corresponding to the data transfer request. The plural transfer controllers are independent and can operate simultaneously in parallel. Each transfer controller includes a read bus interface and a write bus interface which arbitrate with other bus masters in the case of blocking accesses directed to interfering devices or address ranges.

Abstract: A data transfer control apparatus includes a channel controller and a transfer controller. The channel controller receives, prioritizes and queues event signals and predetermined memory writes which trigger data transfer requests controlling the transfer controller. The event queue stores event numbers mapped to parameter memory locations storing data transfer parameters. The mapping table and the parameter memory are writeable via a memory mapped write operation. Memory protection registers store data indicative of permitted data accesses to the memory map.

Abstract: A PCI Express (PCIe) computer system utilizes address translation services to translate virtual addresses from I/O device adaptors to physical addresses of system memory. A combined memory controller and host bridge uses a translation agent to convert the I/O addresses via translation control entries (TCEs) in a TCE table (also known as an address translation and protection table). Some of the I/O device adaptors have address translation caches for local storage of TCEs. The TCE definition includes a new non-cacheable control bit which is set active in the TCE table when the TCE is in the process of being invalidated. The memory controller prevents further caching of the TCE while the non-cacheable control bit is active. A further implementation utilizes a change-in-progress control bit of the TCE to indicate that the TCE is in the process of being changed to allow simultaneous invalidation of the previously TCE information.

Abstract: A memory controller provides page copy logic that assures data coherency when a DMA operation to a page occurs during the copying of the page by the memory controller. The page copy logic compares the page index of the DMA operation to a copy address pointer that indicates the location currently being copied. If the page index of the DMA operation is less than the copy address pointer, the portion of the page that would be written to by the DMA operation has already been copied, so the DMA operation is performed to the physical address of the new page. If the page index of the DMA operation is greater than the copy address pointer, the portion of the page that would be written to by the DMA operation has not yet been copied, so the DMA operation is performed to the physical address of the old page.

Abstract: A data processor capable of preventing the occurrence of overrun, while efficiently performing DMA transfer. An SIO of a data processor starts the transmission of transmission data only when transmission data is stored in a transmission buffer and a reception buffer has no space available for data storage.

Abstract: A request issuing unit for issuing a request signal for requesting data transfer by direct memory access. The request issuing unit including a data presence determination section configured to determine whether or not transfer data, as an object of the data transfer, is present, and a signal outputting section configured to output a request signal for data transfer of a predetermined amount of data to be transferred at one time when the data presence determination section determines that the transfer data is present. The request issuing unit further including a determination timing control section configured to wait for a predetermined waiting period of time, required for completing the data transfer of at least the amount of data to be transferred at one time, after the signal outputting section outputs the request signal, and then makes the data presence determination section determine again whether or not transfer data is present.

Abstract: Methods, systems, and products are disclosed for data transfers between nodes in a parallel computer that include: receiving, by an origin DMA on an origin node, a buffer identifier for a buffer containing data for transfer to a target node; sending, by the origin DMA to the target node, a RTS message; transferring, by the origin DMA, a data portion to the target node using a memory FIFO operation that specifies one end of the buffer from which to begin transferring the data; receiving, by the origin DMA, an acknowledgement of the RTS message from the target node; and transferring, by the origin DMA in response to receiving the acknowledgement, any remaining data portion to the target node using a direct put operation that specifies the other end of the buffer from which to begin transferring the data, including initiating the direct put operation without invoking an origin processing core.

Abstract: In a mobile wireless device, a camera module can be connected directly to a digital baseband processor that does not have a special interface, without the need for an external coprocessor. The data interface of the camera module is directly connected to pins of a general purpose input/output port on the digital baseband processor to enable the baseband processor to capture the synchronous parallel data stream from the camera module. A clock signal from the camera module can be used to trigger DMA transfers of the image data captured by the general purpose input/output port of the baseband processor.

Abstract: Programmatic detection of time-gap defects in computer system hardware where data is corrupted without detection by the computer system. A detection module initiates data transfers between devices in a computer system. An interrupt service routine interrupts the process by inserting a delay into the data transfer. The detection module then checks for time-gap defects by determining if data was corrupted which went undetected by the computer system. The detection module may repeat the data transfer and insert successively longer delays until a time-gap defect is detected or until a maximum delay value is reached. The results of any time-gap defects found may be output to a user. The length of the delays inserted into a data transfer may be determined dynamically using an iterative search technique to more rapidly converge on time-gap defects. Both bisection and Fibonacci search methods are examples that may be used.

Abstract: A communication controller of the present invention includes a descriptor cache mechanism which makes a virtual descriptor gather list from the descriptor indicted from a host, and which allows a processor to refer to a portion of the virtual descriptor gather list in a descriptor cache window. Another communication controller of the present invention includes a second processor which allocates any communication process related with a first communication unit of the communication processes to the first one of a first processors and any communication process related with a second communication unit of the communication processes to the second one of the first processors. Another communication controller includes a first memory which stores control information. The first memory includes a first area accessed by the associated one of processors to refer to the control information and a second area which stores the control information during the access.

Abstract: A distributed direct memory access (DMA) method, apparatus, and system is provided within a system on chip (SOC). DMA controller units are distributed to various functional modules desiring direct memory access. The functional modules interface to a systems bus over which the direct memory access occurs. A global buffer memory, to which the direct memory access is desired, is coupled to the system bus. Bus arbitrators are utilized to arbitrate which functional modules have access to the system bus to perform the direct memory access. Once a functional module is selected by the bus arbitrator to have access to the system bus, it can establish a DMA routine with the global buffer memory.

Abstract: A method and system for communicating information regarding input/output (IO) processing in a shared access to memory environment is disclosed. A central processing unit (CPU) and an input/output processor (IOP) are configured to write to and read from predetermined memory locations to manage the detection, performance, and completion of IOs. The CPU and the IOP may read from and write to memory as desired.

Abstract: A device for attachment to a host for serial data communication including means for transferring to the host a predetermined data structure indicating whether or not the device supports direct memory access.

Abstract: A method of accessing internal memory of a processor and the device thereof. The method employs a bank swapping mechanism for the processing unit of a processor and a direct memory access controller to simultaneously access different memory units in internal memory. The processing unit can continuously access and process data in the internal memory to optimize its efficiency. In the device, the processing unit of a processor and a direct memory access controller are coupled to internal memory through a switching circuit, the switch of which enables the processing unit and the direct memory access controller to access different memory units in the internal memory. Therefore, the processing unit can continuously access and process data in the internal memory to optimize its efficiency.

Abstract: A storage medium drive is controllable by a storage medium array controller. the storage medium array controller receives a data storage medium drive information and the storage medium array controller sets a data transmission parameter with respect to the storage medium drive based on the data storage medium drive information.

Abstract: Methods and structures are described for processing signals formatted according to a plurality of different wireless and broadband standards. In some embodiments, network resources are shared to enable energy efficient, pseudo-simultaneous processing. In some embodiments, a timestamp is prepended to input data to remove jitter associated with time division multiplexed processing using shared resources. Systems according to embodiments of the invention are also disclosed.

Abstract: A priority determining method and apparatus can reduce a total waiting time of DMA request blocks by granting priority to each of Direct Memory Access (DMA) request blocks transmitting a DMA request signal, based on Data Transfer Amounts (DTAs) of the DMA request blocks and Arrival Times (ATs) of the DMA request signals, counting the number of priority changes of each of DMA request blocks whose priority is changed in the priority granting process, and if a DMA request signal is received from a new DMA request block, determining priorities of the DMA request blocks based on the counted the number of priority changes.

Abstract: Coprocessor systems for using a main microprocessor DMA channel to write to a port to control a coprocessor system are provided. In certain examples, coprocessor systems are described using a main CPU counter to trigger a DMA channel to perform a single byte transfer to a port used to control coprocessor command timing.

Abstract: Methods and apparatus are disclosed for processing packets, for example, using a high performance massively parallel packet processing architecture, distributing packets or subsets thereof to individual packet processors and gathering the processed packet or subsets and forwarding the resultant modified or otherwise processed packets, accessing packet processing resources across a shared resource network, accessing packet processing resources using direct memory access techniques, and/or storing one overlapping portion of a packet in a global packet memory while providing a second overlapping portion to a packet processor. In one implementation, the processing of the packet includes accessing one or more processing resources across a resource network shared by multiple packet processing engines. In one implementation, a global packet memory is one of these resources. In one implementation, these resources are accessed using direct memory access (DMA) techniques.

Abstract: In one aspect, an interface adapted to transfer data between a host processor and an external coprocessor is provided. The interface may be adapted to operate in a plurality of write modes, wherein in a first write mode the write operation is transferred across the interface in two clock cycles and in a second write mode the write operation is transferred across the interface in a single clock cycle. In another aspect, the interface is adapted to perform a first read operation initiated by the host processor and a second read operation initiated by the external coprocessor. In another aspect, the interface includes a plurality of buffers to store read and write operations and a plurality of clock gates to selectively gate of clock signals provided to the plurality of buffers to synchronize transfer of data into and out of the buffers.

Abstract: Systems for servicing the data and memory requirements of system devices. A DMA engine that includes a data reservoir is provided that manages and arbitrates the data requests from the system devices. An arbitration unit is provided that only allows eligible devices to make a data request in any given cycle to ensure that all devices will be serviced within a programmable time period. The data reservoir contains the data buffers for each channel of each device. A memory interface ensures that sufficient data for each channel is present in the data reservoir by making requests to a system's memory based on an analysis of each channel. Based on this analysis, a request is either made to the system's main memory, or the channel waits until it is evaluated again in the future. Each channel is thereby guaranteed a response time.

Abstract: A method for intervaled memory transfer access provides periodic authorization signals to a memory access controller. The method cycles between: 1) inhibiting the memory access controller from writing data to a memory until the memory access controller receives a periodic authorization signal to cause the memory access controller to remove the inhibition and write a predetermined amount of data to the memory through a data bus, and 2) releasing the data bus following writing of the predetermined amount of data to the memory by inhibiting the memory access controller from writing further data.

Abstract: A DMA channel data quantity setting section sets a data transfer quantity of each of a plurality of DMA channels in accordance with a data quantity or a ratio in advance. A channel select control circuit determines whether each DMA channel is active. A data transfer control circuit transfers the data of the DMA channel determined to be active by the channel select control circuit in accordance with the data transfer quantity of each DMA channel set by the DMA channel data quantity setting section. By doing so, a plurality of DMA requests are accepted per bus hold request, and the number of bus management right arbitration procedures and the latency between the channels are decreased.

Abstract: A direct memory access (DMA) engine has virtually all control in connection with data transfers that can involve one or both of primary and secondary controllers. The DMA engine receives a command related to a data transfer from a processor associated with the primary controller. This command causes the DMA engine to access processor memory to obtain metadata therefrom. In performing a DMA operation, the metadata enables the DMA engine to conduct data transfers between local memory and remote memory. In performing exclusive OR operations, the DMA engine is involved with conducting data transfers using local memory.

Abstract: A system and method for providing direct memory access is disclosed. In a particular embodiment, a direct memory access module is disclosed that includes a memory, a first interface coupled to a processor, and a second interface coupled to a peripheral module. A first instruction received from the first interface is stored in the memory. The first instruction includes a number of programmed input/output words to be provided to the peripheral module via the second interface. The direct memory access module also includes an instruction execution unit to process the first instruction.

Abstract: Pipe regions PIPE0 to PIPEe (or endpoint regions) are allocated in a packet buffer, registers in which are set page sizes MPS0 to MPe (maximum packet size) and numbers of pages BP0 to BPe for the pipe regions are provided, and data is transferred between pipe regions and endpoints, region sizes RS0 to RSe of the pipe regions being set by the page sizes and numbers of pages. The page sizes and numbers of pages are set in registers that are used in common during both host operation and peripheral operation in accordance with the USB on-the-go standard. Transfer condition information such as transfer types TT0 to TTe is set in the registers, transactions with respect to the endpoints are automatically issued, and data is automatically transferred. Pipe regions are allocated in the packet buffer during host operation whereas endpoint regions are allocated during peripheral operation.

Abstract: An embedded host controller, for use in a USB system comprising a processor and an associated system memory, comprises a DMA controller, and the host controller is adapted such that, in order to retrieve data from the associated system memory, a starting address and block length are sent to the DMA controller, and the DMA controller is adapted such that, on receipt of a starting address and block length sent from the host controller, it retrieves the indicated data from the associated system memory. This has the advantage that the embedded host controller can be used with different host microprocessors, without assuming that PCI functionality is available.

Abstract: In a memory device, data can be transmitted from a first CPU to a second CPU via an individual register or a shared SRAM, for example. The data transmitted from the first CPU to the second CPU via the individual register also passes through a FIFO. When first data is transmitted via the shared SRAM and then second data is transmitted via the individual register, for example, and if the first data transmission is adjusted by a SRAM controller and put into a waiting state at the FIFO, the second data transmitted via the individual register also passes through the FIFO, preventing the second data transmission from being completed earlier than the first data transmission. The data transmissions can therefore be completed appropriately. This in turn increases reliability of the memory device.

Abstract: The present invention uses a Direct Memory Access controller for controlling DMA transfer for a plurality of channels whose priorities are set respectively and receives Data Request Signals for requesting data transfer for the respective channels. The DMA controller executes the DMA transfer for a channel having the highest priority from among the DMA transfer corresponding to the channels that receive the Data Request Signals. The DMA controller sets the priority of a channel used for the DMA transfer to the lowest priority. The DMA controller sets the priorities of other channels used for the DMA transfer to priorities when the DMA transfer is executed or the priorities different therefrom, which are predetermined priority other than the lowest priority.

Abstract: A data converting circuit to receive an input data and convert the input data into an output data is disclosed. An output data group corresponding to the value of the input data is stored beforehand in an output data table. A multiplexer receives the input data and in accordance with the input data, selectively outputs one data out of the output data group stored in the output data table. A specific digit output circuit receives the input data and in accordance with the result of comparing the input data with the boundary information stored in advance, outputs a specific digit output data included in the output data but not output by the multiplexer.

Abstract: A method of transferring data through a bus includes the steps of: occupying the bus by a first device serving as a bus master; transferring a first predetermined number of data items of all data items to be transferred while the first device is occupying the bus; determining if the first predetermined number of data items have been transferred; determining if the first device should release the bus based on whether or not there is a request from a second device after it is determined that the first predetermined number of data items have been transferred; and releasing the bus by the first deice when it is determined that the first device should release the bus.