Datasheet

V850ES/JG3-H, V850ES/JH3-H CHAPTER 21 USB FUNCTION CONTROLLER (USBF)
R01UH0042EJ0500 Rev.5.00 Page 1190 of 1513
Aug 12, 2011
21.9.3 USB main processing
USB main processing involves processing USB transactions. The types of transactions to be processed are as follows.
• Fully automatically processed request for control transfer
• Automatically processed requests for control transfer
(SET_CONFIGURATION, SET_INTERFACE, SET_FEATURE, CLEAR_FEATURE)
• CPUDEC request for control transfer
• Processing for bulk transfer (IN)
• Processing for bulk transfer (OUT)
• Processing for interrupt transfer (IN)
Processing for endpoint n involves writing or reading for data transfer. The flowchart shown below is for PIO.
(1) Fully automatically processed request for control transfer
Because the fully automatically processed request for control transfer is executed by hardware, it cannot be
referenced by FW. Therefore, FW does not have to perform any special processing for this request.
(2) Automatically processed requests for control transfer
(SET_CONFIGURATION, SET_INTERFACE, SET_FEATURE, CLEAR_FEATURE)
Processing to write a register for automatically processed requests for control transfer, such as
SET_CONFIGURATION, SET_INTERFACE, SET_FEATURE, and CLEAR_FEATURE requests, is automatically
executed by hardware, but an interrupt request is issued for recognition on the device side. This processing may be
ignored if there is no special processing to be executed.
The flowcharts are shown below.