Motorola MPC823e Reference Manual page 118

Clocks and Power Control
When none of these conditions exist and the CSRC bit of the PLPRCR is set, the general
system clock automatically switches back to low frequency. When the general system clock
is divided, its duty-cycle is modified. One phase remains the same while the other stretches
out. GCLKx and CLKOUT no longer have a 50% duty cycle when the division factor is
greater than 1, as shown in Figure 5-8 and Figure 5-9.
GCLK1 DIVIDED BY 1
GCLK2 DIVIDED BY 1
GCLK1 DIVIDED BY 2
GCLK2 DIVIDED BY 2
GCLK1 DIVIDED BY 4
GCLK2 DIVIDED BY 4
Figure 5-8. Divided System Clocks Timing Diagram
GCLK1
GCLK2
GCLK1_50
(EBDF=00)
GCLK2_50
(EBDF=00)
CLKOUT
(EBDF=00)
GCLK1_50
(EBDF=01)
GCLK2_50
(EBDF=01)
CLKOUT
(EBDF=01)
Figure 5-9. MPC823e Clocks For Division Factor 2
5-18 MPC823e REFERENCE MANUAL MOTOROLA