Atmel Xplained Pro Evaluation Kit for the ATSAMD21J18A Microcontroller ATSAMD21-XPRO ATSAMD21-XPRO Fiche De Données
Codes de produits
ATSAMD21-XPRO
84
Atmel | SMART SAM D21 [DATASHEET]
Atmel-42181C–SAM-D21_Datasheet–07/2014
14.
GCLK – Generic Clock Controller
14.1 Overview
Several peripherals may require specific clock frequencies to operate correctly. The Generic Clock Controller consists of
number of generic clock generators and generic clock multiplexers that can provide a wide range of clock frequencies.
The generic clock generators can be set to use different external and internal clock sources. The selected clock can be
divided down in the generic clock generator. The outputs from the generic clock generators are used as clock sources for
the generic clock multiplexers, which select one of the sources to generate a generic clock (GCLK_PERIPHERAL), as
shown in
number of generic clock generators and generic clock multiplexers that can provide a wide range of clock frequencies.
The generic clock generators can be set to use different external and internal clock sources. The selected clock can be
divided down in the generic clock generator. The outputs from the generic clock generators are used as clock sources for
the generic clock multiplexers, which select one of the sources to generate a generic clock (GCLK_PERIPHERAL), as
shown in
. The number of generic clocks, m, depends on how many peripherals the device has.
14.2 Features
z
Provides generic clocks
z
Wide frequency range
z
Clock source for the generator can be changed on the fly
14.3 Block Diagram
.
Figure 14-1. Device Clocking Diagram
The Generic Clock Controller block diagram is shown in
.
GCLK_IO
Generic Clock Generator
OSC32K
OSCULP32K
XOSC32K
SYSCTRL
Clock
Divider &
Masker
Divider &
Masker
Clock
Gate
Gate
Generic Clock Multiplexer
PERIPHERALS
GENERIC CLOCK CONTROLLER
PM
GCLK_MAIN
DFLL48M
XOSC
OSC8M
FDPLL96M
GCLK_PERIPHERAL