Using the AT89RFD-08 Board
2-10
AT89RFD-08 Hardware User Guide
4382E–MP3–05/06
2.3.2
CPU Clock
The AT89C51SND2C microcontroller is clocked by a 16MHz crystal (Y1).
Figure 2-8.
Clock Area
2.3.3
PLL Filter
Generation of the 48MHz clock frequency is based on an internal PLL with its two-
capacitors and one-resistor filter.