Datasheet

V850ES/JG3-H, V850ES/JH3-H CHAPTER 21 USB FUNCTION CONTROLLER (USBF)
R01UH0042EJ0500 Rev.5.00 Page 1186 of 1513
Aug 12, 2011
21.9.1 Initialization processing
Initialization processing is executed in the following two ways.
• Initialization of request data register
• Setting of interrupt
When a request data register is initialized, data for the GET_XXXX request to which a value is to be automatically
returned is written and an endpoint is allocated to an interface. In the interrupt settings, the interrupt sources that do not
have to be checked can be masked by using the UF0IMn register (n = 0 to 4).
The following flowcharts illustrate the above processing.
Figure 21-14. Initializing Request Data Register
START
END
EP0NKA = 1?
(UF0E0NA)
Cancels NAK response to Endpoint0.
UF0E0NA register = 01H
Initialization of request
data register
UF0MODC register =
40H or 00H
Yes
No
: See Figure 21-15 Initialization of Request Data Register.
Setting of interface
and endpoint
UF0E0NA register = 00H
: See Figure21-16 Setting of Interface and Endpoint.
If the total number of bytes of the UF0CIEn register exceeds 256,
set the UF0MODC register to 40H. No data has to be written to
the UF0CIEn register.
Remark n = 0 to 255