System information

EPM-15 Reference Manual 46
Appendix B – Generated Frequencies
The following frequencies on the EPM-15 board can be measured for EMI/EMC testing.
Table 20: Generated Frequencies
Component Frequencies Notes
10/100 Ethernet 25 MHz Y1 crystal, U7 82551ER chip.
RTC 32.768 kHz Y2 crystal, U13A CS5536 chip.
System Clock
REF Clock
IOAPC Clock
PCI Clock
14.318 MHz
14.318 MHz
14.318 MHz
33.3 MHz
Y3 crystal, U34 MK1491-09F chip.
USB 48 MHz Y4 crystal, U13B CS5536 chip.
Audio 24.576 MHz Y5 crystal, U44 AD1981B chip.
PCI Bus 33.3 MHz Fixed frequency.
ISA Bus 8 MHz
VCore Switching
Regulator
1 MHz Switching frequency.
Memory 111 MHz or 222
transfers per second
BB