Abstract:
A universal serial bus (USB) transaction translator is provided along with a micro-frame synchronization method. A device interface is coupled to a device via a device bus, and a host interface is coupled to a host via a host bus. At least two buffers are configured to store data. A controller stores the data in the buffers alternately. A start-of-frame (SOF) counter is used to count the SOF packets, with the counting value of the SOF counter being compared to a predefined value. Specifically, the controller resets a SOF timer for sending the SOF packet when the counting value achieves or exceeds the predefined value, such that the SOF packet and an isochronous timestamp packet (ITP) from the host are sent at the same time. Further, the controller delays the sending of the SOF packet for a period of time according to the ITP from the host.
Abstract:
A universal serial bus (USB) transaction translator is provided along with a micro-frame synchronization method. A device interface is coupled to a device via a device bus, and a host interface is coupled to a host via a host bus. At least two buffers are configured to store data. A controller stores the data in the buffers alternately. A start-of-frame (SOF) counter is used to count the SOF packets, with the counting value of the SOF counter being compared to a predefined value. Specifically, the controller resets a SOF timer for sending the SOF packet when the counting value achieves or exceeds the predefined value, such that the SOF packet and an isochronous timestamp packet (ITP) from the host are sent at the same time. Further, the controller delays the sending of the SOF packet for a period of time according to the ITP from the host.
Abstract:
A data transmission system and method are provided. The data transmission method receives a second format data packet sent by a host; decodes the second format data packet sent by the host, and translating the decoded second format data packet into a first format data packet; transmits the first format data packet to a first device; receives a transmission response sent by the first device in response to the first format data packet, determines whether to transmit the transmission response to the host, and performs a re-try flow when the transmission response does not need to be transmitted to the host. Preferably, a data transmission rate of the first device is slower than that of a second device, and the data transmission system is backward compatible to the first device, and the second format data packet is consistent with the second device.