Universal Serial Bus; Usb Function Control Unit (Usb Fcu) - Renesas M16C Series User Manual

M30240 Group

1.2.18 Universal Serial Bus

The Universal Serial Bus (USB) has the following features:
• Complete USB Specification (version 1.1) Compatibility
• Error-handling capabilities
• FIFOs:
• Endpoint 0:IN/OUT 32-byte
• Endpoint 1:IN 128-byteOUT 128-byte
• Endpoint 2:IN 32-byteOUT 32-byte
• Endpoint 3:IN 32-byteOUT 32-byte
• Endpoint 4:IN 32-byteOUT 32-byte
• Nine endpoints - control endpoint (Endpoint 0 - bi-directional) plus four IN and four OUT endpoints
• Complete device configuration
• Support of all device commands
• Supports of full-speed functions
• Support of all USB transfer types:
• Isochronous
• Bulk
• Control
• Interrupt
• Suspend/Resume operation
• On-chip USB transceiver with voltage converter
• Start-of-frame interrupt and output pin

1.2.18.1 USB Function Control Unit (USB FCU)

The implementation of the USB by this device is accomplished chiefly through the device's USB Func-
tion Control Unit (See Figure 1.29). The Function Control Unit's overall purpose is to handle the USB
packet protocol layer. The Function Control Unit notifies the MCU that a valid token has been received.
When this occurs, the data portion of the token is routed to the appropriate FIFO. The MCU transfers
the data to, or from, the host by interacting with that endpoint's FIFO and CSR register.
The USB Function Control Unit is composed of five sections:
• Serial Interface Engine (SIE)
• Generic Function Interface (GFI)
• Serial Engine Interface Unit (SIU)
• Microcontroller Interface (MCI)
• USB Transceiver
1.2.18.1.1 Serial Interface Engine
The SIE interfaces to the USB serial data and handles deserialization/serialization of data, NRZI encoding de-
coding, clock extraction, CRC generation and checking, bit stuffing, and other items pertaining to the USB pro-
tocol such as handling inter-packet time-outs and packet ID (PID) decoding.
Rev.1.00 Sep 24, 2003 Page 41 of 360
Universal Serial Bus