Abstract: A data transfer control device and an electronic instrument which can implement a process to be made on data transmitted and received through a high speed bus on a circuit operating at a low frequency. The data transfer control device has a conversion circuit which converts K-bit width data transferred at a frequency FC1 (in USB 2.0 HS mode) through a bus into data having an L-bit width (L>K) by rearranging, and a processing circuit which receives the L-bit width data from the conversion circuit and carries out a K-bit based process on an L-bit basis at a frequency FC2 lower than FC1. This enables to perform the K-bit based process at the low frequency FC2. Configuration on a transmission end can be implemented in the same manner. The transfer data in the USB 2.0 HS mode is processed on the L-bit basis while the transfer data in the FS mode is processed on the K-bit basis. The present invention is applicable also to the process on data transferred through a bus under the IEEE1394 or SCSI.

Abstract: An electronic instrument including: an upstream port UPPT provided on a side surface SF1 of the electronic instrument; a downstream port DWPT provided on a side surface SF2 which is a surface of the electronic instrument and opposite to the side surface SF1; and a data transfer control device which is connected to the upstream port UPPT and the downstream port DWPT and controls data transfer through the upstream port UPPT and data transfer through the downstream port DWPT.

Abstract: A transceiver includes upstream differential signal lines DPUP and DMUP, downstream differential signal lines DPDW and DMDW, common differential signal lines DPCM and DMCM, a first transmission driver of which outputs are connected to DPUP and DMUP, a second transmission driver of which outputs are connected to DPDW and DMDW, a first switch circuit which connects the first transmission driver to a logic circuit during upstream connection and connects the second transmission driver to the logic circuit during downstream connection, a second switch circuit which respectively connects DPUP and DMUP to DPCM and DMCM during the upstream connection and respectively connects DPDW and DMDW to DPCM and DMCM during the downstream connection, and a third transmission driver connected to DPCM and DMCM.

Abstract: A data transfer control device including a buffer is provided which includes an EP2 area (a data storage area set to FIFO) and a CSW area (a randomly accessible status storage area), when data and a CSW are allocated as information to be transferred through one end point EP2. When a phase has switched from a USE data phase (data transport) to a status phase (status transport), the information read area is switched from the EP2 area to the CSW area. and IN data to be transferred from the end point EP2 to a host is read from the CSW area. A CSW0 area for success status and a CSW1 area for non-success status are provided, and a status block packet in which is set either success or non-success default information is previously written therein.

Abstract: A buffer is provided which includes an EP2 area (a data storage area set to FIFO) and a CSW area (a randomly accessible status storage area), when data and a CSW are allocated as information to be transferred through one end point EP2. When a phase has switched from a USB data phase (data transport) to a status phase (status transport), the information read area is switched from the EP2 area to the CSW area, and IN data to be transferred from the end point EP2 to a host is read from the CSW area. A CSW0 area for success status and a CSW1 area for non-success status are provided, and a status block packet in which is set either success or non-success default information is previously written therein.

Abstract: A clock generation circuit capable of generating a high-frequency clock with a simple circuit configuration, together with a data transfer control device and an electronic instrument using the same. The clock generation circuit has: serially-connected inversion circuits IV0 to IV4 in which an output of IV4 is connected to an input of IV0 by a feedback line FL; and buffer circuits BF0 to BF4 which receives outputs from IV0 to IV4. The inversion circuits IV0 to IV4 are disposed along a line LN1 and the buffer circuits BF0 to BF4 are disposed along a line LN2 that is parallel to the feedback line FL but different from LN1. Dummy lines DL0 to DL3 each of which having parasitic capacitance that is equal to that of the feedback line FL are connected to the inversion circuits IV0 to IV3, to equalize the phase differences between clocks CK0 to CK4. The feedback line FL and the dummy lines DL0 to DL3 are disposed in a region between the inversion circuits IV0 to IV4 and the buffer circuits BF0 to BF4.

Abstract: The objective of the present invention is to provide a data transfer control device that enables a reduction in the processing load on the firmware during the occurrence of a bus reset, and electronic equipment using the same. A data transfer control device in accordance with the IEEE 1394 standard generates a bit BT that toggles whenever one received packet and the next received packet are received in different bus reset intervals, and comprises that BT in the header of each packet stored in RAM. Bus reset pointers (a bus reset header pointer and a bus reset ORB pointer) that indicate a bus reset boundary in RAM are provided, enabling simple differentiation between a packet received before a bus reset occurred and a packet received after the reset. If transmission has been halted by the occurrence of the bus reset, the bus reset transmission halt status is passed to the firmware via a register.

Abstract: A data transfer control device and an electronic instrument which can implement a process to be made on data transmitted and received through a high speed bus on a circuit operating at a low frequency. The data transfer control device has a conversion circuit which converts K-bit width data transferred at a frequency FC1 (in USB 2.0 HS mode) through a bus into data having an L-bit width (L>K) by rearranging, and a processing circuit which receives the L-bit width data from the conversion circuit and carries out a K-bit based process on an L-bit basis at a frequency FC2 lower than FC1. This enables to perform the K-bit based process at the low frequency FC2. Configuration on a transmission end can be implemented in the same manner. The transfer data in the USB 2.0 HS mode is processed on the L-bit basis while the transfer data in the FS mode is processed on the K-bit basis. The present invention is applicable also to the process on data transferred through a bus under the IEEE1394 or SCSI.

Abstract: A data transfer control device using USB (a first bus), the end of a data phase (data transport: transfer of all the data) during an OUT transaction is determined on condition that data transmission (DMA transfer) through EBUS (a second bus) has ended, and the end of a data phase during an IN transaction is determined on condition that data reception through EBUS has ended and also an Empty signal has gone active, indicating that a data storage area has become empty. A counter that counts the data size is provided on the EBUS side. If data reception through EBUS ends and the size of data remaining in the data storage area is less than the maximum packet size, a short packet in the data storage area is transmitted automatically through USB and an interrupt is used to notify the firmware of the presence of the short packet.

Abstract: An objective of the present invention is to provide a data transfer control device and electronic equipment which make it possible to reduce processing overheads in the firmware and implement high-speed data transfer. In a data transfer control device in accordance with the IEEE 1394 standard, the header of a packet is written to a header area, the ORB (data for SBP-2) of the packet is written to an ORB area, and the stream (data for the application layer) of the packet is written to a stream area. The stream area is managed by hardware in accordance with full and empty signals. Indication information is comprised within a transaction label tl of a request packet, and the header, ORB, and stream of a response packet are written to areas indicated by the indication information comprised within tl, when the response packet is received.

Abstract: A data transfer control device and an electronic instrument which can implement a process to be made on data transmitted and received through a high speed bus on a circuit operating at a low frequency. The data transfer control device has a conversion circuit which converts K-bit width data transferred at a frequency FC1 (in USB 2.0 HS mode) through a bus into data having an L-bit width (L>K) by rearranging, and a processing circuit which receives the L-bit width data from the conversion circuit and carries out a K-bit based process on an L-bit basis at a frequency FC2 lower than FC1. This enables to perform the K-bit based process at the low frequency FC2. Configuration on a transmission end can be implemented in the same manner. The transfer data in the USB 2.0 HS mode is processed on the L-bit basis while the transfer data in the FS mode is processed on the K-bit basis. The present invention is applicable also to the process on data transferred through a bus under the IEEE1394 or SCSI.

Abstract: An objective of the present invention is to provide a data transfer control device and electronic equipment which make it possible to reduce processing overheads in the firmware and implement high-speed data transfer. In a data transfer control device in accordance with the IEEE 1394 standard, the header of a packet is written to a header area, the ORB (data for SBP-2) of the packet is written to an ORB area, and the stream (data for the application layer) of the packet is written to a stream area. The stream area is managed by hardware in accordance with full and empty signals. Indication information is comprised within a transaction label t1 of a request packet, and the header, ORB, and stream of a response packet are written to areas indicated by the indication information comprised within t1, when the response packet is received.

Abstract: The objective is to provide a data transfer control device and electronic equipment that are capable of reducing processing overheads, thus enabling high-speed data transfer within a compact hardware configuration. During IEEE 1394 data transfer, a packet assembly circuit (280) reads a header and data for a packet from header and data areas in a RAM (80) and links them together. The period of time during which a header CRC is created is used to obtain a data pointer. Whether a header or data is being read is determined by tcode, and the header pointer or data pointer incremented accordingly. A header is created while data is being fetched from the data area. Data is fetched to one channel which a packet is being transmitted from another channel within a divided send packet area. A linkage pointer is used to sequentially read a packet from another channel. An ACK code from the transfer destination is written back to the channel that sent the corresponding packet.

Abstract: A transfer controller (or a host controller) issues IN tokens to a plurality of USB devices connected to USB and including first and second USB devices. When data including destination information which specifies the second USB device as a destination has been received in response to an IN token issued to the first USB device, the transfer controller issues an OUT token to the second USB device and transmits the received data from the first USB device to the second USB device. The transfer controller issues an IN token to at least one of the USB devices which has declared itself to be a local area network (LAN) node.

Abstract: The objective is to provide a data transfer control device and electronic equipment that are capable of reducing processing overheads, thus enabling high-speed data transfer within a compact hardware configuration. In a data transfer control device in accordance with IEEE 1394, a packet shaping circuit (160) shapes each packet that is transferred in from another node into a form that can be used by an upper layer, and a packet division circuit (180) writes the header of the thus-shaped packet into a header area in RAM and the data thereof into a data area. A data pointer that has been passed from the packet division circuit is appended to the header of the packet during packet shaping. Tags are used to divide packets. Information indicating broadcast information, error status information, and whether or not the packet was received during a self-ID period is appended to the trailer of the packet during the packet shaping.

Abstract: The objective is to provide a data transfer control device and electronic equipment that make it possible to utilize the resources possessed by each node efficiently, thus reducing processing overheads. A packet shaping circuit receives a self-ID packet conforming to the IEEE 1394 standard from each of the nodes, shapes a packet having a frame made of a single header and data that is formed from an assembled series of self-ID packets, and interfaces with an upper layer. Parity information is erased from each self-ID packet, data of the packet is formed from these assembled self-ID packets without the parity information, and also error status information is appended to a trailer of parity information. The header of the packet is written to a header area and the data thereof is written to a data area, and also a data pointer indicating the address of the data is appended to the header of the packet. An area that is dedicated to self-ID packets is provided in the data area.

Abstract: The objective is to provide a data transfer control device and electronic equipment that are capable of reducing processing overheads, thus enabling high-speed data transfer within a compact hardware configuration. In addition to a FIFO, an internal RAM capable of storing packets in a randomly accessible manner is provided between a link core and a CPU in a data transfer control device conforming to the IEEE 1394 standard. The RAM storage area is divided into a header area, a data area, and a CPU work area, and the header and data areas are divided into areas for reception and transmission. Tags are used to write the header of a receive packet to the header area and the data thereof to the data area. The data area is divided into areas for isochronous transfer and asynchronous transfer. Pointers are provided for controlling the size of each area in RAM variably, and the size of each area can be varied dynamically after power is switched on. Each area has a ring buffer structure.

Abstract: The present invention provides a serial/parallel conversion circuit that has both a serial/parallel conversion function and a buffer function for absorbing clock frequency differences, together with a data transfer control device and electronic equipment. The serial/parallel conversion circuit (elasticity buffer) comprises a data holding register which holds serial data DIN that is input based on a CLK1 clock (480 MHz) in USB 2.0 HS mode; a determination circuit which determines whether or not held data is valid, by unit of a data cell; and a selector which outputs from the data holding register the data of data cells that have been determined to be valid, based on a CLK2 clock (60 MHz) having a frequency lower than that of CLK1. A data cell in which data of the first bit has been determined to be valid is deemed to be valid in the next CLK2 clock cycle.

Abstract: A transaction is automatically issued with respect to one of end points and data is automatically transferred while the remaining data size of the transfer data is calculated based on the total size and the maximum packet size. When the remaining data size in the current transaction is less than the maximum packet size, the next transaction is issued automatically, and a short packet is transferred automatically to nest one of the end points. When the payload size of the packet to be transferred by the current transaction is the maximum packet size and the remaining data size of the transfer data is zero, a short packet of zero data length is transferred automatically to the next one of the end points. When DMA transfer is complete and the remaining data to be transferred is zero, a short packet of zero data length is transferred automatically in response to an IN token from a host. Data transfer according to USB On-The-Go is performed.

Abstract: When a first mode (with-SOF mode) has been set, data transfer is performed while SOF packets are transferred at frame periods, and when a second mode (non-SOF mode) has been set and also non-periodic (bulk) transfer is being performed, the periodic transfer of SOF packets is disabled and non-periodic data is transferred. If there is no non-periodic data to be transferred, a SOF packet is transferred in the frame period, even if the second mode has been set. During host operation with USB on-the-go (OTG), pipe regions are allocated to the packet buffer, and non-periodic data is transferred automatically to or from end points while the periodic transfer of SOF packets is disabled. When all of the automatic transfer instruction signals of the pipe regions are inactive, SOF packets are transferred periodically even if the second mode has been set.