H8SSLASH2218 datasheet(564/750 Pages) RENESAS

564 / 750 page

Section 14 Universal Serial Bus (USB)

Rev.6.00 Jun. 03, 2008 Page 516 of 698

REJ09B0074-0600

14.5.8

Processing of USB Standard Commands and Class/Vendor Commands

(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 by the firmware. Whether or not command decoding is required by the

firmware is indicated in table 14.5 below.

Table 14.5

Command Decoding by Firmware

Decoding not Necessary by Firmware

Decoding Necessary by Firmware

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 by the firmware, 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 by the firmware, the USB function module stores the command in the

EP0s FIFO. After normal reception is completed, the SetupTS flag in UIER0 is set and an

interrupt request is generated from the

EXIRQx pin. In the interrupt routine, eight bytes of data

must be read from the EP0s data register (UEDR0s) and decoded by the firmware. The

necessary data stage and status stage processing should then be carried out according to the

result of the decoding operation.

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