AN2539 Freescale Semiconductor / Motorola, AN2539 Datasheet - Page 4

• Manufacturer Part Number: AN2539
• Description: Using the MC9328MX1/MC9328MXL Single Internal 32.768 kHz Crystal to Generate System Clock and USB
• Manufacturer: Freescale Semiconductor / Motorola

Conclusions
5 Conclusions
6 Appendix
Appendix attached: USB Certification Test Results
4
1. There is no significant difference shown in jitter measurement results for the 48 MHz USB
2. With the single internal 32.768 kHz crystal generating both system clock and 48 MHz USB
3. In view of broad space saving and cost minimization issues, Motorola recommends using
clock generated by the internal 32.768kHz crystal or an external 16 MHz crystal.
clock, the MC9328MX1/MC9328MXL processors pass the USB revision 1.1 requirements
at full speed device test and can achieve USB certification.
the single internal 32.768 kHz crystal used by the MCU PLL and System PLL to generate
both the system clock and the 48 MHz USB clock.
Freescale Semiconductor, Inc.
MC9328MX1/MC9328MXL Application Note
For More Information On This Product,
Go to: www.freescale.com
MOTOROLA