Motorola ColdFire MCF5281 - Manual (Page 174)

Clock Module
9-4 Freescale Semiconductor
Figure 9-2. PLL Block Diagram
9.5 Signal Descriptions
The clock module signals are summarized in Table 9-2 and a brief description follows. For more detailed
information, refer to Chapter 14, “Signal Descriptions .”
9.5.1 EXTAL
This input is driven by an external clock except when used as a connection to the external crystal when
using the internal oscillator.
Table 9-2. Signal Properties
Name Function
EXTAL Oscillator or clock input
XTAL Oscillator output
CLKOUT System clock output
CLKMOD[1:0] Clock mode select inputs
RSTOUT Reset signal from reset controller
STPMD CLKMOD[1:0] RSTOUT
÷ MFD
(4–18)
LOCKS
LOCK
LOCS
TO RESET
MODULE
CLKOUT
PLLSEL
DISCLK MDF[2:0]
PHASE AND
FREQUENCY
DETECT
LOSS OF
CLOCK
DETECT
LOCK
DETECT
CHARGE
PUMP
FILTER VCO RFD[2:0]
SCALED PLL
CLOCK OUT
PLL CLOCK
OUT
REFERENCE
CLOCK
LOCEN
LOLRE
PLLMODE
LOCRE
MCF5282 and MCF5216 ColdFire Microcontroller User’s Manual, Rev. 3