h8s-2172 Renesas Electronics Corporation., h8s-2172 Datasheet - Page 386

• Manufacturer Part Number: h8s-2172
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family H8s-2100 Series
• Manufacturer: Renesas Electronics Corporation.

12.5.7
1. Processing of Requests Transmitted by Control Transfer
Table 12.2 Request Decoding by Firmware
Rev. 2.00, 03/04, page 354 of 534
Decoding not Necessary by Firmware
Clear Feature
Get Configuration
Get Interface
Get Status
Set Address
Set Configuration
Set Feature
Set Interface
A request transmitted from the host by control transfer may require decoding and execution of
request processing by the firmware. Whether or not request decoding is required by the
firmware is indicated in table 12.2 below.
If decoding is not necessary by the firmware, request 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, this module stores the request in the EP0s FIFO.
After normal reception is completed, the SETUPTS flag in IER0 is set and an interrupt request
is generated. In the interrupt routine, eight bytes of data must be read from the EP0s data
register (EPDR0s) 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.
Processing of USB Standard Requests and Class/Vendor Requests
Decoding Necessary by Firmware
Get Descriptor
Synch Frame
Set Descriptor
Class/Vendor request