HD6417660 RENESAS [Renesas Technology Corp], HD6417660 Datasheet - Page 647

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

20.8.7
Figure 20.21 shows an example flow of clearing and transition to software standby mode.
When accessing the USBF again after software standby mode has been cleared, wait for operation
stabilization time of the USB clock (48 MHz).
Figure 20.21 Example Flow of Clearing and Transition to Software Standby Mode
Example flow of transition to software standby mode
Note on Clearing and Transition to Software Standby Mode
ISR0/SURES IS is cleared to 0 or set to 1
IRQ7 is enabled and set to be detected
Detection of USB bus in suspend state
IFR0/SURSS and SURSF are set to 1
Transition to software standby mode
Interrupt request by INT0N or INT1N
(Execution of SLEEP instruction )
Interrupt by suspend is enabled
IFR0/SURSF is cleared to 0
Description
IER0/SURES IE is set to 1
IFR0/SURSS = 1?
at falling edge
YES
Operation by software setting
Automatic processing by hardware of the LSI
without transition to software
NO
Normal state is kept
standby mode
Example flow of clear software standby mode
Waiting for EXCPGCR/USBVALID = 1
Software standby mode is cleared
USB clock oscillation is stabilized
EXCPGCR/USBVALID is set to 1
IRQ7 is output at low falling edge
Waiting for USB clock oscillation
USB bus resume is detected
IFR0/SURSF is cleared to 0
IRR0/IRQ7R is cleared to 0
Rev. 1.00, 02/04, page 609 of 804
stabilization time