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Section 26 USB 2.0 Host/Function Module
R01UH0134EJ0400 Rev. 4.00 Page 1497 of 2108
Sep 24, 2014
SH7262 Group, SH7264 Group
1. Conditions under which SOF lock monitoring begins
USBE = 1
2. Conditions under which SOF lock monitoring stops
USBE = 0, a USB bus reset is received, or suspended state is detected.
6
701 670 701 70170 12
7012345670123456701
346
Peripheral Device
µSOF packet
µSOF packet
µSOF lock
µSOF number
µSOF number
µSOF lock
Frame number
SOFR interrupt
SOFR interrupt
SOF interpolation
SOF interpolation function
SOF interpolation SOF interpolation
SOF interpolation,
missing
Not locked Not locked
Figure 26.8 Example of SOFR Interrupt Output Timing
(7) VBUS Interrupt
If there has been a change in the VBUS pin, the VBUS interrupt is generated. The level of the
VBUS pin can be checked with the VBSTS bit in INTSTS0. Whether the host controller is
connected or disconnected can be confirmed using the VBUS interrupt. However, if the system is
activated with the host controller connected, the first VBUS interrupt is not generated because
there is no change in the VBUS pin.
(8) Resume Interrupt
With the function controller function selected, the resume interrupt is generated when the USB bus
state changes (from J-state to K-state, or from J-state to SE0) while the device state is the
suspended state.. Recovery from the suspended state is detected by means of the resume interrupt.
With the host controller function selected, the resume interrupt is not generated; use the BCHG
interrupt to detect the change of the USB bus state.