CHAPTER 12 USB FUNCTION CONTROLLER (USBF)
Preliminary User’s Manual U19014EJ1V0UD
356
12.7.1 Initialization processing
Initialization processing is executed in the following two ways.
•
Initialization of request data register
•
Setting of interrupt
When the 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 12-9. 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 12-10 Initialization of Request Data Register
.
Setting of interface
and endpoint
UF0E0NA register = 00H
:
See
Figure 12-11 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
electronic components distributor