Datasheet

Section 22 USB Function Module (USB)
Rev. 2.00 Aug. 20, 2008 Page 892 of 1198
REJ09B0403-0200
22.10.7 Restrictions on Peripheral Module Clock (φ) Operating Frequency
The USB clock select pin (UXSEL) can be used to select the clock source. To set the USB
dedicated clock (cku) at 48 MHz, specify the peripheral module clock (φ) as shown in table 22.8.
Operation cannot be guaranteed if any frequency other than in the following table is specified.
When UXSEL is set to 0, connect UEXTAL to the system power supply (0 V).
The USB operates only in high-speed mode and does not operate in medium-speed mode.
Table 22.8 Selection of Peripheral Module Clock (φ) when USB Connection is Made
UXSEL
UEXTAL Input
Frequency
EXTAL Input
Frequency
USB Dedicated Clock
(cku: 48 MHz)
φ
0  8.00 MHz EXTAL × 6 EXTAL × 4 (32 MHz)
1 8.00 MHz 8.50 MHz UEXTAL × 6 EXTAL × 4 (34 MHz)