AT90PWM216-16SE ATMEL [ATMEL Corporation], AT90PWM216-16SE Datasheet - Page 28

• Manufacturer Part Number: AT90PWM216-16SE
• Description: 8-bit Microcontroller with 16K Bytes In-System Programmable flash
• Manufacturer: ATMEL [ATMEL Corporation]

7. System Clock
7.1
7.1.1
7.1.2
28
Clock Systems and their Distribution
AT90PWM216/316
CPU Clock – clk
I/O Clock – clk
I/O
Figure 7-1
need not be active at a given time. In order to reduce power consumption, the clocks to unused
modules can be halted by using different sleep modes, as described in
Sleep Modes” on page
Figure 7-1.
The CPU clock is routed to parts of the system concerned with operation of the AVR core.
Examples of such modules are the General Purpose Register File, the Status Register and the
data memory holding the Stack Pointer. Halting the CPU clock inhibits the core from performing
general operations and calculations.
The I/O clock is used by the majority of the I/O modules, like Timer/Counters, SPI, USART. The
I/O clock is also used by the External Interrupt module, but note that some external interrupts
are detected by asynchronous logic, allowing such interrupts to be detected even if the I/O clock
is halted.
CPU
presents the principal clock systems in the AVR and their distribution. All of the clocks
PSC0/1/2
PLL Input
Multiplexer
PLL
Clock Distribution AT90PWM216/316
CLK
PLL
39. The clock systems are detailed below.
General I/O
Modules
clk
I/O
External Clock
Clock
Multiplexer
ADC
Control Unit
AVR Clock
clk
ADC
Source Clock
Oscillator)
(Crystal
CPU Core
clk
clk
CPU
FLASH
Reset Logic
Watchdog Clock
RAM
“Power Management and
Watchdog
Oscillator
Watchdog Timer
7710D–AVR–08/09
Flash and
EEPROM
Calibrated RC
Oscillator