Freescale Semiconductor MC9S08PT60, Reference Manual

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8.3.4 Initializing FBE mode
The following code segment demonstrates setting ICS to FBE mode.
Example: 8.3.4.1 FBE mode initialization routine
/* the following code segment demonstrates setting ICS to FBE mode generating 20MHZ bus*/
/* supposing external 20MHZ crystal is installed in high gain mode */
ICS_OSCSC = 0x96; /* high-range, high-gain, oscillator required */
while (ICS_OSCINIT == 0); /* waiting until oscillator is ready */
ICS_C1 = 0x80; /* external clock reference (20MHZ) to FLL output */
ICS_C2 = 0x00; /* BDIV = 0, prescalar = 1 */
8.3.5 External oscillator (OSC)
The oscillator module provides the reference clock for internal reference clock module
(ICS), the real time counter clock module, and other MCU sub-systems.
OSCOUT
OSCINIT
High Gain
Oscillator
MCU
EXTAL
XTAL
Rs
R
F
C1
C2
X1
EN
XTLCLK
Initialization
Oscillator
Low-Powe r
LP
RANGE
OSCOS
Figure 8-4. Oscillator module block diagram
Chapter 8 Clock management
MC9S08PT60 Reference Manual, Rev. 4, 08/2014
Freescale Semiconductor, Inc. 213