HD6417660 RENESAS [Renesas Technology Corp], HD6417660 Datasheet - Page 541

• Manufacturer Part Number: HD6417660
• Description: Renesas 32-Bit RISC Microcomputer
• Manufacturer: RENESAS [Renesas Technology Corp]

Bit
3
2
Bit Name
USBRESET 1
USBHSTP
Initial
Value
0
R/W
R/W
R/W
Descriptions
USB Reset
The USB module reset bit to be used to reset the USB
module (both the USB host and USB function controllers).
If this bit is cleared to 0, the USBVALID bit is cleared to 0
after approximately 1 µs. After checking that the
USBVALID bit is cleared to 0, set the USBRESET bit to 1.
After this USBRESET bit is set to 1, the USB module
starts the reset sequence. After the reset sequence, the
USBVALID bit is set to 1 again. To ensure USB module
initialization, follow the above sequence.
To provide a clock again to the USB module after the
clock has been stopped using the USBHSTP and
USBFSTP bits, USB module operation may be unstable.
Therefore, use the USB module after resetting by this bit.
0: USB module is reset.
1: USB module is in normal operation.
Module Stop USBH
The USB host controller stop bit to be used to provide or
stop the USB host controller operating clock. Clearing this
bit to 0 provides the clock to the USB host controller.
Setting this bit to 1 stops the clock. If both the USBHSTP
and USBFSTP bits are set to 1 or cleared to 0, the USB
transceiver operation stops. The USB_P and the USB_N
outputs pins enter the high-impedance state, and then
USB_PWR_EN/USB_PULLUP pin is brought low. Before
using the USB host or USB function controller, clear one
of USBHSTP or USBFSTP to 0. Note that the USB host
controller and USB function controller cannot be used
simultaneously. If the USB module control register is
accessed while both the USBHSTP and USBFSTP bits
are cleared to 0, correct operation cannot be guaranteed.
Note that the USB host controller register access is
ignored while the clock provided to the USB host
controller is stopped.
0: USB host controller operation continues.
1: Stop providing clock to the USB host controller.
Rev. 1.00, 02/04, page 503 of 804