Chapter 5 Clock Generation Module (MC_CGM)
MPC5602P Microcontroller Reference Manual, Rev. 4
120
Freescale Semiconductor
Figure 5-12. MC_CGM System Clock Generation Overview
5.7.1
System Clock Source Selection
During normal operation, the system clock selection is controlled
•
on a SAFE mode or reset event, by the MC_RGM
•
otherwise, by the MC_ME
5.7.2
System Clock Disable
During the TEST
mode, the system clock can be disabled by the MC_ME.
5.7.3
System Clock Dividers
The MC_CGM generates the divided system clock 0 - controlled by the CGM_SC_DC0 register.
5.8
Auxiliary Clock Generation
shows the block diagram of the auxiliary clock generation logic. See
Clock 0 Select Control Register (CGM_AC0_SC)
Section 5.5.7, “Auxiliary Clock 1 Select Control
, and
Section 5.5.9, “Auxiliary Clock 2 Select Control Register
for auxiliary clock selection control.
4 MHz crystal osc.
2
system PLL
4
system clock
’0’
CGM_SC_SS
Register
MC_RGM
SAFE
mode request
ME_<current mode>
_MC.SYSCLK
CGM_SC_DC0
Register
clock divider
divided system clock 0
system clock is disabled if
ME_<current mode>_MC.SYSCLK
= “1111”
“0000”
1
0
16 MHz int. RC osc.
0