Xerox M20 - WorkCentre B/W Laser, Руководство по обслуживанию

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December 2006
6-50 WorkCentre M20, 4118, FaxCentre 2218 Family
GP 15
General Procedures and Information
USB Interface
For details, refer to the relevant sections:
• M20F USB Interface (Option: Direct Kit/Network Kit)
• 4118/2218 USB Interface
M20F USB Interface (Option: Direct Kit/Network Kit)
Refer to Figure 1
Figure 1 USB interface
Features
• USB Specification Version 2.0 Compliant (high and full speed).
• Interfaces between a local CPU bus and a USB bus.
• Supports USB Full Speed (12 Mbps) and High Speed (480 Mbps).
• Supports optional Split Bus DMA, with dedicated DMA and CPU access.
• Provides 3 Configurable Physical Endpoints, in addition to Endpoint 0.
• Provides 30 Configurable Virtual Endpoints.
• Each endpoint can be lsochronous, Bulk, or Interrupt, as well as IN or OUT.
• Supports high-bandwidth isochronous mode.
• Supports Max Packet Size up to 1K bytes, double buffered.
• Internal 3 Kbyte memory provides transmit and receive buffers.
• Local CPU bus easily interfaces to generic CPUs.
• 8-bit or 16-bit CPU or DMA bus transfers.
• Multiple register address modes supports both direct and indirect register addressing.
• Automatic retry of failed packets.
• Diagnostic register allows forced USB errors.
• Software controlled disconnect allows re-enumeration.
• Atomic operation to set and clear status bits, simplifying software.
• Low power CMOS in 64 Pin Plastic TQFP Package.
• 30 MHz oscillator with internal phase-lock loop multiplier.
• Provides an output clock to the local bus-8 programmable frequencies from OFF to 60
MHz.
• 2.5V, 3.3V operating voltages with 5V tolerant I/O.
4118/2218 USB Interface
Features
• Automatic Hi-Speed USB mode detection and Original USB fall-back mode.
• Supports sharing mode.
• Supports VBUS sensing.
• High-speed DMA interface.
• Fully autonomous and multiconfiguration DMA operation.
• 7 IN endpoints, 7 OUT endpoints and a fixed control IN/OUT endpoint.
• Integrated physical 8 kbytes of multiconfiguration FIFO memory.
• Endpoints with double buffering to increase throughput and ease real-time data transfer.
• Bus-independent interface with most microcontrollers and microprocessors.
• 12 MHz crystal oscillator with integrated PLL for low EMI.
• Software-controlled connection to the USB bus (SoftConnect™).
• Low-power consumption in operation and power-down modes; suitable for use in.
• Bus-powered USB devices.