MC9S08GB60 Datasheet, PDF (101/290 Pages) Motorola, Inc – Microcontrollers

External Signal Description
7.1.2 Modes of Operation
This is a high-level description only. Detailed descriptions of operating modes are contained in
Section 7.3, “Functional Description."
• Mode 1 — Off
The output clock, ICGOUT, is static. This mode may be entered when the STOP instruction is
executed.
• Mode 2 — Self-clocked (SCM)
Default mode of operation that is entered out of reset. The ICG’s FLL is open loop and the digitally
controlled oscillator (DCO) is free running at a frequency set by the filter bits.
• Mode 3 — FLL engaged internal (FEI)
In this mode, the ICG’s FLL is used to create frequencies that are programmable multiples of the
internal reference clock.
— FLL engaged internal unlocked is a transition state which occurs while the FLL is attempting
to lock. The FLL DCO frequency is off target and the FLL is adjusting the DCO to match the
target frequency.
— FLL engaged internal locked is a state which occurs when the FLL detects that the DCO is
locked to a multiple of the internal reference.
• Mode 4 — FLL bypassed external (FBE)
In this mode, the ICG is configured to bypass the FLL and use an external clock as the clock source.
• Mode 5 — FLL engaged external (FEE)
The ICG’s FLL is used to generate frequencies that are programmable multiples of the external
clock reference.
— FLL engaged external unlocked is a transition state which occurs while the FLL is attempting
to lock. The FLL DCO frequency is off target and the FLL is adjusting the DCO to match the
target frequency.
— FLL engaged external locked is a state which occurs when the FLL detects that the DCO is
locked to a multiple of the internal reference.
7.2 External Signal Description
7.2.1 Overview
Table 7-1 shows the user-accessible signals available for the ICG.
Table 7-1. Signal Properties
Name
Function
EXTAL
XTAL
External clock/oscillator input
Oscillator output
Reset State
Analog input
Analog output
MC9S08GB/GT Data Sheet, Rev. 2.3
Freescale Semiconductor
101