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Published byJeremy Skinner Modified over 9 years ago
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Introduction to USB © 2010 Renesas Electronics America Inc. All rights reserved.
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USB = Universal Serial Bus HID Class Mass Storage Class Printer Class Serial bus standard for interfacing devices Advantages Hot Swapable Multiple Classes with unified drivers Large number of devices (128) High data transfer rates – 1.5Mbps (Low Speed) – 12 Mbps (Full Speed) – 480 Mbps (High Speed USB 2.0) – 3Gbps (Super Speed USB 3.0) Differential signaling Automatic Error Detection and Recovery Examples: © 2010 Renesas Electronics America Inc. All rights reserved.
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Topology Three Device Types Host Only one per system Function Any device that connects to a host Hub Self Powered Bus Powered Peripheral Device Device HUB Peripheral Device Device Peripheral Device Device Peripheral Device Device HUB Peripheral Device Peripheral Device Device Peripheral Device Device USB Cable Port USB HUB USB © 2010 Renesas Electronics America Inc. All rights reserved.
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On-The-Go USB Allows two USB devices to talk to each other without a PC acting as host. Allows two USB devices to talk to each other without a PC acting as host. DRD (Dual Role Device). DRD (Dual Role Device). Functions as both Device and Host Functions as both Device and Host Limited Host capabilities Limited Host capabilities Unique mini-AB receptacle. Unique mini-AB receptacle. Common applications Common applications Cell phones Cell phones MP3 players MP3 players PDA PDA OTG © 2010 Renesas Electronics America Inc. All rights reserved.
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Four kinds Four kinds Control Control Interrupt Interrupt Bulk Bulk Isochronous Isochronous Direction is from the host perspective Direction is from the host perspective IN: Data sent to host IN: Data sent to host OUT: Data received from host OUT: Data received from host Endpoint FIFO size determines transfer rate Endpoint FIFO size determines transfer rate Endpoints USB a uniquely addressable portion of a USB device that is either a source or sink of info in a communications flow. Bidirectional Unidirectional Fixed at Zero (0 ) IN only Separate Send/Receive Endpoints Direction Endpoint Notes © 2010 Renesas Electronics America Inc. All rights reserved.
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Control Transfers Control Transfers Intended to support configuration, command and status operations between the software on the host and the device Required for all USB function devices Bidirectional Interrupt Transfers Interrupt Transfers Intended for devices that send and receive small amounts of data infrequently or in an asynchronous time frame Full speed up to 64 bytes/packet Data is ACK’ed (error correcting) Transfer Types USB © 2010 Renesas Electronics America Inc. All rights reserved.
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Transfer Types USB Bulk Transfers Bulk Transfers Transfer large amounts of non-time sensitive data, and that can use any available bandwidth Data is ACK’ed (error correcting) Not Guaranteed for latency Transfer time dependent on Bus activity Isochronous transfers Isochronous transfers Transfer data at guaranteed time intervals Example – Audio/video streaming Guaranteed bus bandwidth Data is not ACK’ed (not error correcting) © 2010 Renesas Electronics America Inc. All rights reserved.
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Defined by USB Implementers Forum Defined by USB Implementers Forum Group of devices or interfaces with similar attributes or services Group of devices or interfaces with similar attributes or services Examples of commonly used classes Examples of commonly used classes MSC (Mass Storage Class) MSC (Mass Storage Class) HID (Human Interface Device) HID (Human Interface Device) Other important classes Other important classes Audio, Video Audio, Video Vendor Specific Vendor Specific Classes USB © 2010 Renesas Electronics America Inc. All rights reserved.
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Enumeration USB Control Endpoint Endpoint 0 (EP0) Endpoint 3 (EP3) Interrupt IN Endpoint HID HIDDriver Request for Device Descriptor Request for Interface Descriptor Interface Descriptor Request for Configuration Descriptor Request for Report Descriptor Report Descriptor Reply with Configuration Descriptor Configuration Descriptor Reply with Interface Descriptor Interface Descriptor Reply with Endpoint Descriptor Reply with Report Descriptor Report Descriptor Reply with Device Descriptor Device Descriptor Request for Endpoint Descriptor Endpoint Descriptor © 2010 Renesas Electronics America Inc. All rights reserved. * 6 th Descriptor = String Descriptor
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Start of Frame KeyboardMouse USB Speakers Bus Management Printer, Scanner and bulk transfers Control Interruptand/orcontrol Isochronous Control Bulk Frame USB 1 ms or 0.125 ms © 2010 Renesas Electronics America Inc. All rights reserved.
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USB Transfer on the protocol analyzer © 2010 Renesas Electronics America Inc. All rights reserved.
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Type a H8S2215 Type b H8S2218 H8S2212 Type c H8S2472 Type d H8SX1653 H8SX1663 H8SX1658R H8SX1668R Controller types USB line-up © 2010 Renesas Electronics America Inc. All rights reserved.
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The H8SX1664, H8S2218/2212 EndpointAbbrev. Transfer type Maximum packet size FIFO capacity (Bytes) DMA transfer Endpoint 0EP0Control88- Endpoint 1EP1Bulk-IN64128Possible Endpoint 2EP2Bulk-OUT64128Possible Endpoint 3EP3Interrupt88- EndpointAbbrev. Transfer type Maximum packet size FIFO capacity (Bytes) DMA transfer Endpoint 0EP0Control864- Endpoint 1EP1Bulk-OUT64128Possible Endpoint 2EP2Bulk-IN64128Possible Endpoint 3EP3Interrupt64 - H8SX1664 H8S2218/2212 © 2010 Renesas Electronics America Inc. All rights reserved.
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The H8S/2215 Self/USB powered Can use either System clock or External Clock for USB Configurable endpoint addresses H8S/2215 Self/USB powered Can use either System clock or External Clock for USB Configurable endpoint addresses © 2010 Renesas Electronics America Inc. All rights reserved.
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MSDHIDCDC Bulk-Only with GUI and source H8S/2215 RSK/Web Web H8S/2212/2218 Web H8SX1664 / 1668 RSK/Web Web H8S/2472 RSK/Web - Open source USB library LibUSB-Win32. Host stack available from Renesas and third party vendors like Micrium. USB software © 2010 Renesas Electronics America Inc. All rights reserved.
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Renesas Electronics America Inc. Thank You
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