HT45B0K
SPI to USB Bridge
is set to 0. When the MCU detects the suspend mode SUSP, the resume signal RESUME
which causes MCU to wake up should be remembered and taken into consideration.
URST: USB reset indication flag
Bit 2
Bit 1
0: No USB reset event occurred.
1: USB reset event has occurred.
The USB bit is set and cleared by USB SIE. When the URST bit is set to 1, it indicates
that a USB reset event has occurred and a USB interrupt will be initiated.
RMWK: USB remote wake-up command
0: disable USB remote wake-up command
1: initiate USB remote wake-up command
The RMWK is set to 1 by MCU to force the USB host leaving the suspend mode. Set
RMWK bit to 1 to initiate the remote walk-up command. When the RMWK bit is set to 1,
a 2μs delay for clearing this bit to 0 is necessary to ensure that the RMWK command is
accepted by the SIE.
Bit 0
SUSP: USB suspend indication flag
0: USB leaves the suspend mode.
1: USB enters the suspend mode.
This bit is read only and set to 1 by SIE to indicate that the USB bus enters the suspend
mode.
The USB interrupt is also generated when the SUSP bit is asserted.
USR Register
The USR (USB endpoint interrupt status register) register is consisted of the endpoint request
flags (EP0IF~EP5IF) used to indicate which endpoint is accessed. When an endpoint is accessed,
the related endpoint request flag will be set to 1 by SIE and a USB interrupt will be generated if
the control bits related to the USB interrupt are enabled and the stack in the host MCU is not full.
When the active endpoint request flag is serviced, the endpoint request flag has to be cleared to 0
by application program.
USR Register
Bit
7
6
5
4
3
2
1
0
Name
R/W
―
―
―
―
―
―
EP5IF
R/W
0
EP4IF
R/W
0
EP3IF
R/W
0
EP2IF
R/W
0
EP1IF
R/W
0
EP0IF
R/W
0
POR
Bit 7~6
Bit 5~0
Unimplemented, read as “0”.
EP5IF~EP0IF: Endpoint Interrupt request flags
0: the corresponding Endpoint is not accessed.
1: the corresponding Endpoint has been accessed.
Rev 1.00
9
March 22, 2010
HOLTEK [ HOLTEK SEMICONDUCTOR INC ]
