CHAPTER 12 USB FUNCTION CONTROLLER (USBF)
Preliminary User’s Manual U19014EJ1V0UD
298
(13) UF0 INT status 2 register (UF0IS2)
This register indicates the interrupt source. If the contents of this register are changed, the INTUSB1B signal
becomes active.
This register is read-only, in 8-bit units.
If an interrupt request (INTUSB1B) is generated from USBF, the FW must read this register to identify the
interrupt source.
Each bit of this register is forcibly cleared to 0 when 0 is written to the corresponding bit of the UF0IC2 register.
The related bits are invalid if each endpoint is not supported by the setting of the UF0E1IM register and the
current setting of the interface.
0
UF0IS2
0
5
BKI1IN
BKI1DT
3
0
2
0
1
0
0
Address
FF29H
After reset
00H
0
4
6
7
Bit position
Bit name
Function
5
BKI1IN
This bit indicates that an IN token has been received in the UF0BI1 register (Endpoint 1)
and that NAK has been returned.
1: IN token is received and NAK is transmitted (interrupt request is generated).
0: IN token is not received (default value).
4
BKI1DT
This bit indicates that the FIFO of the UF0BI1 register (Endpoint 1) has been toggled.
This means that data can be written to Endpoint 1.
1: FIFO has been toggled (interrupt request is generated).
0: FIFO has not been toggled (default value).
The data written to Endpoint 1 is transmitted in synchronization with the IN token next to
the one that set the BKI1NK bit of the UF0EN register to 1. When the FIFO has been
toggled and then data can be written from the CPU, this bit is automatically set to 1 by
hardware. It is also set to 1 when the FIFO has been toggled, even if the data is a Null
packet. This bit is automatically cleared to 0 by hardware when the first write access is
made to the UF0BI1 register.
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