EZ-USB Datasheet, PDF (215/334 Pages) Cypress Semiconductor – The EZ-USB USB Integrated Circuit

Bit 2:
SUTOKIR SETUP Token Interrupt Request
The EZ-USB core sets this bit to “1” when it receives a SETUP token. Write a “1” to this
bit to clear the interrupt request. See Chapter 7, "EZ-USB Endpoint Zero" for more infor-
mation on the handling of SETUP tokens.
Because this bit can change state while the 8051 is in reset, it may be active when the 8051
comes out of reset, although it is reset to “0” by a power-on reset.
Bit 1:
SOFIR
Start of frame Interrupt Request
The EZ-USB core sets this bit to “1” when it receives a SOF packet. Write a “1” to this bit
to clear the interrupt condition.
Because this bit can change state while the 8051 is in reset, it may be active when the 8051
comes out of reset, although it is reset to “0” by a power-on reset.
Bit 0:
SUDAVIR SETUP data available Interrupt Request
The EZ-USB core sets this bit to “1” when it has transferred the eight data bytes from an
endpoint zero SETUP packet into internal registers (at SETUPDAT). Write a “1” to this
bit to clear the interrupt condition.
Because this bit can change state while the 8051 is in reset, it may be active when the 8051
comes out of reset, although it is reset to “0” by a power-on reset.
Page 12-22
Chapter 12. EZ-USB Registers
EZ-USB TRM v1.9