beautypg.com

Renesas SH7641 User Manual

Page 829

background image

Section 20 USB Function Module

Rev. 4.00 Sep. 14, 2005 Page 779 of 982

REJ09B0023-0400

20.5

Processing of USB Standard Commands and Class/Vendor
Commands

20.5.1

Processing of Commands Transmitted by Control Transfer

A command transmitted from the host by control transfer may require decoding and execution of
command processing on the application side. Whether command decoding is required on the
application side is indicated in table 20.2 below.

Table 20.2 Command Decoding on Application Side

Decoding not Necessary on Application Side

Decoding Necessary on Application Side

Clear feature

Get configuration

Get interface

Get status

Set address

Set configuration

Set feature

Set interface

Get Descriptor

Synch Frame

Set Descriptor

Class/Vendor command

If decoding is not necessary on the application side, command decoding and data stage and status
stage processing are performed automatically. No processing is necessary by the user. An interrupt
is not generated in this case.

If decoding is necessary on the application side, the USB function module stores the command in
the EP0s FIFO. After normal reception is completed, the USBIER0/SETUP TS flag is set and an
interrupt request is generated. In the interrupt routine, 8 bytes of data must be read from the EP0s
data register (USBEPDR0S) and decoded by firmware. The necessary data stage and status stage
processing should then be carried out according to the result of the decoding operation.

This manual is related to the following products: