Figure 18.14 Operation Procedure For Initializing Usb Module - Renesas H8S/2158 User Manual

Section 18 Universal Serial Bus Interface (USB)
External Event, Host
Cancel reset (RES = 1)
Check if a new device is
connected
Send a bus reset signal

Figure 18.14 Operation Procedure for Initializing USB Module

Rev. 3.00 Jan 25, 2006 page 624 of 872
REJ09B0286-0300
USB Function Core
Start USB operating
clock oscillation
Supply the USB
operating clock
Set the USB function
core to operate
Start DPLL operation
Cancel the USB
function core reset
Set EPINFO
Receive a bus reset signal
Process a bus reset
Core Interface
Set the BRSTF bit of
USBIFR0 to 1
Request an USBID
interrupt (BRSTF)
Slave CPU
Start system operation
Check if the USB cable
is connected
Cancel the module stop
state of the USB module
Set the VBUSS bit of
USBCR1 to 1
Set UPLLCR
Wait for the PLL
stabilization time (3 ms)
Set the CK48READY bit
of USBCR1 to 1
Clear the UIFRST bit of
USBCR0 to 0
Write to the USB function
core control registers
Clear the FPLLRST bit of
USBCR0 to 0
Wait for the DPLL
stabilization time
Clear the FSRST bit of
USBCR0 to 0
Write EPINFO to EPDR0I
and set the EPIVLD bit of
USBCSR0 to 1
Externally pull up
the USDP pin
Initiate the USBID
interrupt processing
Read USBIFR0 and
check if a BRSTF
interrupt occurs or not
Complete the USBID
interrupt processing